August 2024 - Kernel - mailweb.openeuler.org

[PATCH openEuler-1.0-LTS] f2fs: let's avoid panic if extent_tree is not created
by Long Li 26 Aug '24

26 Aug '24

From: Jaegeuk Kim <jaegeuk(a)kernel.org> stable inclusion from stable-v4.19.270 commit ff85a1dbd90d29f73033177ff8d8de4a27d9721c category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IALL7L CVE: CVE-2022-48877 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?h=… -------------------------------- [ Upstream commit df9d44b645b83fffccfb4e28c1f93376585fdec8 ] This patch avoids the below panic. pc : __lookup_extent_tree+0xd8/0x760 lr : f2fs_do_write_data_page+0x104/0x87c sp : ffffffc010cbb3c0 x29: ffffffc010cbb3e0 x28: 0000000000000000 x27: ffffff8803e7f020 x26: ffffff8803e7ed40 x25: ffffff8803e7f020 x24: ffffffc010cbb460 x23: ffffffc010cbb480 x22: 0000000000000000 x21: 0000000000000000 x20: ffffffff22e90900 x19: 0000000000000000 x18: ffffffc010c5d080 x17: 0000000000000000 x16: 0000000000000020 x15: ffffffdb1acdbb88 x14: ffffff888759e2b0 x13: 0000000000000000 x12: ffffff802da49000 x11: 000000000a001200 x10: ffffff8803e7ed40 x9 : ffffff8023195800 x8 : ffffff802da49078 x7 : 0000000000000001 x6 : 0000000000000000 x5 : 0000000000000006 x4 : ffffffc010cbba28 x3 : 0000000000000000 x2 : ffffffc010cbb480 x1 : 0000000000000000 x0 : ffffff8803e7ed40 Call trace: __lookup_extent_tree+0xd8/0x760 f2fs_do_write_data_page+0x104/0x87c f2fs_write_single_data_page+0x420/0xb60 f2fs_write_cache_pages+0x418/0xb1c __f2fs_write_data_pages+0x428/0x58c f2fs_write_data_pages+0x30/0x40 do_writepages+0x88/0x190 __writeback_single_inode+0x48/0x448 writeback_sb_inodes+0x468/0x9e8 __writeback_inodes_wb+0xb8/0x2a4 wb_writeback+0x33c/0x740 wb_do_writeback+0x2b4/0x400 wb_workfn+0xe4/0x34c process_one_work+0x24c/0x5bc worker_thread+0x3e8/0xa50 kthread+0x150/0x1b4 Signed-off-by: Jaegeuk Kim <jaegeuk(a)kernel.org> Signed-off-by: Sasha Levin <sashal(a)kernel.org> Signed-off-by: Long Li <leo.lilong(a)huawei.com> --- fs/f2fs/extent_cache.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/f2fs/extent_cache.c b/fs/f2fs/extent_cache.c index a70cd2580eae..785e956d04e6 100644 --- a/fs/f2fs/extent_cache.c +++ b/fs/f2fs/extent_cache.c @@ -375,7 +375,8 @@ static bool f2fs_lookup_extent_tree(struct inode *inode, pgoff_t pgofs, struct extent_node *en; bool ret = false; - f2fs_bug_on(sbi, !et); + if (!et) + return false; trace_f2fs_lookup_extent_tree_start(inode, pgofs); -- 2.39.2

2 1

[PATCH] f2fs: let's avoid panic if extent_tree is not created
by Long Li 26 Aug '24

26 Aug '24

From: Jaegeuk Kim <jaegeuk(a)kernel.org> stable inclusion from stable-v4.19.270 commit ff85a1dbd90d29f73033177ff8d8de4a27d9721c category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IALL7L CVE: CVE-2022-48877 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?h=… -------------------------------- [ Upstream commit df9d44b645b83fffccfb4e28c1f93376585fdec8 ] This patch avoids the below panic. pc : __lookup_extent_tree+0xd8/0x760 lr : f2fs_do_write_data_page+0x104/0x87c sp : ffffffc010cbb3c0 x29: ffffffc010cbb3e0 x28: 0000000000000000 x27: ffffff8803e7f020 x26: ffffff8803e7ed40 x25: ffffff8803e7f020 x24: ffffffc010cbb460 x23: ffffffc010cbb480 x22: 0000000000000000 x21: 0000000000000000 x20: ffffffff22e90900 x19: 0000000000000000 x18: ffffffc010c5d080 x17: 0000000000000000 x16: 0000000000000020 x15: ffffffdb1acdbb88 x14: ffffff888759e2b0 x13: 0000000000000000 x12: ffffff802da49000 x11: 000000000a001200 x10: ffffff8803e7ed40 x9 : ffffff8023195800 x8 : ffffff802da49078 x7 : 0000000000000001 x6 : 0000000000000000 x5 : 0000000000000006 x4 : ffffffc010cbba28 x3 : 0000000000000000 x2 : ffffffc010cbb480 x1 : 0000000000000000 x0 : ffffff8803e7ed40 Call trace: __lookup_extent_tree+0xd8/0x760 f2fs_do_write_data_page+0x104/0x87c f2fs_write_single_data_page+0x420/0xb60 f2fs_write_cache_pages+0x418/0xb1c __f2fs_write_data_pages+0x428/0x58c f2fs_write_data_pages+0x30/0x40 do_writepages+0x88/0x190 __writeback_single_inode+0x48/0x448 writeback_sb_inodes+0x468/0x9e8 __writeback_inodes_wb+0xb8/0x2a4 wb_writeback+0x33c/0x740 wb_do_writeback+0x2b4/0x400 wb_workfn+0xe4/0x34c process_one_work+0x24c/0x5bc worker_thread+0x3e8/0xa50 kthread+0x150/0x1b4 Signed-off-by: Jaegeuk Kim <jaegeuk(a)kernel.org> Signed-off-by: Sasha Levin <sashal(a)kernel.org> Signed-off-by: Long Li <leo.lilong(a)huawei.com> --- fs/f2fs/extent_cache.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/f2fs/extent_cache.c b/fs/f2fs/extent_cache.c index a70cd2580eae..785e956d04e6 100644 --- a/fs/f2fs/extent_cache.c +++ b/fs/f2fs/extent_cache.c @@ -375,7 +375,8 @@ static bool f2fs_lookup_extent_tree(struct inode *inode, pgoff_t pgofs, struct extent_node *en; bool ret = false; - f2fs_bug_on(sbi, !et); + if (!et) + return false; trace_f2fs_lookup_extent_tree_start(inode, pgofs); -- 2.39.2

1 0

[PATCH openEuler-22.03-LTS-SP1] f2fs: let's avoid panic if extent_tree is not created
by Long Li 26 Aug '24

26 Aug '24

From: Jaegeuk Kim <jaegeuk(a)kernel.org> stable inclusion from stable-v5.10.164 commit 72009139a661ade5cb1da4239734ed02fa1cfff0 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IALL7L CVE: CVE-2022-48877 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?h=… -------------------------------- [ Upstream commit df9d44b645b83fffccfb4e28c1f93376585fdec8 ] This patch avoids the below panic. pc : __lookup_extent_tree+0xd8/0x760 lr : f2fs_do_write_data_page+0x104/0x87c sp : ffffffc010cbb3c0 x29: ffffffc010cbb3e0 x28: 0000000000000000 x27: ffffff8803e7f020 x26: ffffff8803e7ed40 x25: ffffff8803e7f020 x24: ffffffc010cbb460 x23: ffffffc010cbb480 x22: 0000000000000000 x21: 0000000000000000 x20: ffffffff22e90900 x19: 0000000000000000 x18: ffffffc010c5d080 x17: 0000000000000000 x16: 0000000000000020 x15: ffffffdb1acdbb88 x14: ffffff888759e2b0 x13: 0000000000000000 x12: ffffff802da49000 x11: 000000000a001200 x10: ffffff8803e7ed40 x9 : ffffff8023195800 x8 : ffffff802da49078 x7 : 0000000000000001 x6 : 0000000000000000 x5 : 0000000000000006 x4 : ffffffc010cbba28 x3 : 0000000000000000 x2 : ffffffc010cbb480 x1 : 0000000000000000 x0 : ffffff8803e7ed40 Call trace: __lookup_extent_tree+0xd8/0x760 f2fs_do_write_data_page+0x104/0x87c f2fs_write_single_data_page+0x420/0xb60 f2fs_write_cache_pages+0x418/0xb1c __f2fs_write_data_pages+0x428/0x58c f2fs_write_data_pages+0x30/0x40 do_writepages+0x88/0x190 __writeback_single_inode+0x48/0x448 writeback_sb_inodes+0x468/0x9e8 __writeback_inodes_wb+0xb8/0x2a4 wb_writeback+0x33c/0x740 wb_do_writeback+0x2b4/0x400 wb_workfn+0xe4/0x34c process_one_work+0x24c/0x5bc worker_thread+0x3e8/0xa50 kthread+0x150/0x1b4 Signed-off-by: Jaegeuk Kim <jaegeuk(a)kernel.org> Signed-off-by: Sasha Levin <sashal(a)kernel.org> Signed-off-by: Long Li <leo.lilong(a)huawei.com> --- fs/f2fs/extent_cache.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/f2fs/extent_cache.c b/fs/f2fs/extent_cache.c index bd16c78b5bf2..ad0b83a41226 100644 --- a/fs/f2fs/extent_cache.c +++ b/fs/f2fs/extent_cache.c @@ -414,7 +414,8 @@ static bool f2fs_lookup_extent_tree(struct inode *inode, pgoff_t pgofs, struct extent_node *en; bool ret = false; - f2fs_bug_on(sbi, !et); + if (!et) + return false; trace_f2fs_lookup_extent_tree_start(inode, pgofs); -- 2.39.2

2 1

[PATCH openEuler-22.03-LTS-SP1] tty: serial: qcom-geni-serial: fix slab-out-of-bounds on RX FIFO buffer
by Cai Xinchen 26 Aug '24

26 Aug '24

From: Krzysztof Kozlowski <krzysztof.kozlowski(a)linaro.org> stable inclusion from stable-v5.10.165 commit 894681682dbefdad917b88f86cde1069140a047a category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IALLEM CVE: CVE-2022-48871 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id… -------------------------------- commit b8caf69a6946e18ffebad49847e258f5b6d52ac2 upstream. Driver's probe allocates memory for RX FIFO (port->rx_fifo) based on default RX FIFO depth, e.g. 16. Later during serial startup the qcom_geni_serial_port_setup() updates the RX FIFO depth (port->rx_fifo_depth) to match real device capabilities, e.g. to 32. The RX UART handle code will read "port->rx_fifo_depth" number of words into "port->rx_fifo" buffer, thus exceeding the bounds. This can be observed in certain configurations with Qualcomm Bluetooth HCI UART device and KASAN: Bluetooth: hci0: QCA Product ID :0x00000010 Bluetooth: hci0: QCA SOC Version :0x400a0200 Bluetooth: hci0: QCA ROM Version :0x00000200 Bluetooth: hci0: QCA Patch Version:0x00000d2b Bluetooth: hci0: QCA controller version 0x02000200 Bluetooth: hci0: QCA Downloading qca/htbtfw20.tlv bluetooth hci0: Direct firmware load for qca/htbtfw20.tlv failed with error -2 Bluetooth: hci0: QCA Failed to request file: qca/htbtfw20.tlv (-2) Bluetooth: hci0: QCA Failed to download patch (-2) ================================================================== BUG: KASAN: slab-out-of-bounds in handle_rx_uart+0xa8/0x18c Write of size 4 at addr ffff279347d578c0 by task swapper/0/0 CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.1.0-rt5-00350-gb2450b7e00be-dirty #26 Hardware name: Qualcomm Technologies, Inc. Robotics RB5 (DT) Call trace: dump_backtrace.part.0+0xe0/0xf0 show_stack+0x18/0x40 dump_stack_lvl+0x8c/0xb8 print_report+0x188/0x488 kasan_report+0xb4/0x100 __asan_store4+0x80/0xa4 handle_rx_uart+0xa8/0x18c qcom_geni_serial_handle_rx+0x84/0x9c qcom_geni_serial_isr+0x24c/0x760 __handle_irq_event_percpu+0x108/0x500 handle_irq_event+0x6c/0x110 handle_fasteoi_irq+0x138/0x2cc generic_handle_domain_irq+0x48/0x64 If the RX FIFO depth changes after probe, be sure to resize the buffer. Fixes: f9d690b6ece7 ("tty: serial: qcom_geni_serial: Allocate port->rx_fifo buffer in probe") Cc: <stable(a)vger.kernel.org> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski(a)linaro.org> Reviewed-by: Jiri Slaby <jirislaby(a)kernel.org> Link: https://lore.kernel.org/r/20221221164022.1087814-1-krzysztof.kozlowski@lina… Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> Signed-off-by: Cai Xinchen <caixinchen1(a)huawei.com> --- drivers/tty/serial/qcom_geni_serial.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c index 0d85b55ea823..f50ffc8076d8 100644 --- a/drivers/tty/serial/qcom_geni_serial.c +++ b/drivers/tty/serial/qcom_geni_serial.c @@ -866,9 +866,10 @@ static irqreturn_t qcom_geni_serial_isr(int isr, void *dev) return IRQ_HANDLED; } -static void get_tx_fifo_size(struct qcom_geni_serial_port *port) +static int setup_fifos(struct qcom_geni_serial_port *port) { struct uart_port *uport; + u32 old_rx_fifo_depth = port->rx_fifo_depth; uport = &port->uport; port->tx_fifo_depth = geni_se_get_tx_fifo_depth(&port->se); @@ -876,6 +877,16 @@ static void get_tx_fifo_size(struct qcom_geni_serial_port *port) port->rx_fifo_depth = geni_se_get_rx_fifo_depth(&port->se); uport->fifosize = (port->tx_fifo_depth * port->tx_fifo_width) / BITS_PER_BYTE; + + if (port->rx_fifo && (old_rx_fifo_depth != port->rx_fifo_depth) && port->rx_fifo_depth) { + port->rx_fifo = devm_krealloc(uport->dev, port->rx_fifo, + port->rx_fifo_depth * sizeof(u32), + GFP_KERNEL); + if (!port->rx_fifo) + return -ENOMEM; + } + + return 0; } @@ -890,6 +901,7 @@ static int qcom_geni_serial_port_setup(struct uart_port *uport) u32 rxstale = DEFAULT_BITS_PER_CHAR * STALE_TIMEOUT; u32 proto; u32 pin_swap; + int ret; proto = geni_se_read_proto(&port->se); if (proto != GENI_SE_UART) { @@ -899,7 +911,9 @@ static int qcom_geni_serial_port_setup(struct uart_port *uport) qcom_geni_serial_stop_rx(uport); - get_tx_fifo_size(port); + ret = setup_fifos(port); + if (ret) + return ret; writel(rxstale, uport->membase + SE_UART_RX_STALE_CNT); -- 2.34.1

2 1

[PATCH openEuler-1.0-LTS] usb: vhci-hcd: Do not drop references before new references are gained
by Zheng Yejian 26 Aug '24

26 Aug '24

From: Oliver Neukum <oneukum(a)suse.com> stable inclusion from stable-v4.19.320 commit 5a3c473b28ae1c1f7c4dc129e30cb19ae6e96f89 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAM59O CVE: CVE-2024-43883 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id… -------------------------------- commit afdcfd3d6fcdeca2735ca8d994c5f2d24a368f0a upstream. At a few places the driver carries stale pointers to references that can still be used. Make sure that does not happen. This strictly speaking closes ZDI-CAN-22273, though there may be similar races in the driver. Signed-off-by: Oliver Neukum <oneukum(a)suse.com> Cc: stable <stable(a)kernel.org> Acked-by: Shuah Khan <skhan(a)linuxfoundation.org> Link: https://lore.kernel.org/r/20240709113851.14691-1-oneukum@suse.com Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> Signed-off-by: Zheng Yejian <zhengyejian1(a)huawei.com> --- drivers/usb/usbip/vhci_hcd.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/drivers/usb/usbip/vhci_hcd.c b/drivers/usb/usbip/vhci_hcd.c index d5a036bf904b..c1bc3bd2098d 100644 --- a/drivers/usb/usbip/vhci_hcd.c +++ b/drivers/usb/usbip/vhci_hcd.c @@ -741,6 +741,7 @@ static int vhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb, gfp_t mem_flag * */ if (usb_pipedevice(urb->pipe) == 0) { + struct usb_device *old; __u8 type = usb_pipetype(urb->pipe); struct usb_ctrlrequest *ctrlreq = (struct usb_ctrlrequest *) urb->setup_packet; @@ -751,14 +752,15 @@ static int vhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb, gfp_t mem_flag goto no_need_xmit; } + old = vdev->udev; switch (ctrlreq->bRequest) { case USB_REQ_SET_ADDRESS: /* set_address may come when a device is reset */ dev_info(dev, "SetAddress Request (%d) to port %d\n", ctrlreq->wValue, vdev->rhport); - usb_put_dev(vdev->udev); vdev->udev = usb_get_dev(urb->dev); + usb_put_dev(old); spin_lock(&vdev->ud.lock); vdev->ud.status = VDEV_ST_USED; @@ -777,8 +779,8 @@ static int vhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb, gfp_t mem_flag usbip_dbg_vhci_hc( "Not yet?:Get_Descriptor to device 0 (get max pipe size)\n"); - usb_put_dev(vdev->udev); vdev->udev = usb_get_dev(urb->dev); + usb_put_dev(old); goto out; default: @@ -1061,6 +1063,7 @@ static void vhci_shutdown_connection(struct usbip_device *ud) static void vhci_device_reset(struct usbip_device *ud) { struct vhci_device *vdev = container_of(ud, struct vhci_device, ud); + struct usb_device *old = vdev->udev; unsigned long flags; spin_lock_irqsave(&ud->lock, flags); @@ -1068,8 +1071,8 @@ static void vhci_device_reset(struct usbip_device *ud) vdev->speed = 0; vdev->devid = 0; - usb_put_dev(vdev->udev); vdev->udev = NULL; + usb_put_dev(old); if (ud->tcp_socket) { sockfd_put(ud->tcp_socket); -- 2.25.1

2 1

[PATCH OLK-5.10] btrfs: get rid of warning on transaction commit when using flushoncommit
by Yifan Qiao 26 Aug '24

26 Aug '24

From: Filipe Manana <fdmanana(a)suse.com> mainline inclusion from mainline-v5.17-rc5 commit a0f0cf8341e34e5d2265bfd3a7ad68342da1e2aa category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IALPT4 CVE: CVE-2022-48920 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?… -------------------------------- When using the flushoncommit mount option, during almost every transaction commit we trigger a warning from __writeback_inodes_sb_nr(): $ cat fs/fs-writeback.c: (...) static void __writeback_inodes_sb_nr(struct super_block *sb, ... { (...) WARN_ON(!rwsem_is_locked(&sb->s_umount)); (...) } (...) The trace produced in dmesg looks like the following: [947.473890] WARNING: CPU: 5 PID: 930 at fs/fs-writeback.c:2610 __writeback_inodes_sb_nr+0x7e/0xb3 [947.481623] Modules linked in: nfsd nls_cp437 cifs asn1_decoder cifs_arc4 fscache cifs_md4 ipmi_ssif [947.489571] CPU: 5 PID: 930 Comm: btrfs-transacti Not tainted 95.16.3-srb-asrock-00001-g36437ad63879 #186 [947.497969] RIP: 0010:__writeback_inodes_sb_nr+0x7e/0xb3 [947.502097] Code: 24 10 4c 89 44 24 18 c6 (...) [947.519760] RSP: 0018:ffffc90000777e10 EFLAGS: 00010246 [947.523818] RAX: 0000000000000000 RBX: 0000000000963300 RCX: 0000000000000000 [947.529765] RDX: 0000000000000000 RSI: 000000000000fa51 RDI: ffffc90000777e50 [947.535740] RBP: ffff888101628a90 R08: ffff888100955800 R09: ffff888100956000 [947.541701] R10: 0000000000000002 R11: 0000000000000001 R12: ffff888100963488 [947.547645] R13: ffff888100963000 R14: ffff888112fb7200 R15: ffff888100963460 [947.553621] FS: 0000000000000000(0000) GS:ffff88841fd40000(0000) knlGS:0000000000000000 [947.560537] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [947.565122] CR2: 0000000008be50c4 CR3: 000000000220c000 CR4: 00000000001006e0 [947.571072] Call Trace: [947.572354] <TASK> [947.573266] btrfs_commit_transaction+0x1f1/0x998 [947.576785] ? start_transaction+0x3ab/0x44e [947.579867] ? schedule_timeout+0x8a/0xdd [947.582716] transaction_kthread+0xe9/0x156 [947.585721] ? btrfs_cleanup_transaction.isra.0+0x407/0x407 [947.590104] kthread+0x131/0x139 [947.592168] ? set_kthread_struct+0x32/0x32 [947.595174] ret_from_fork+0x22/0x30 [947.597561] </TASK> [947.598553] ---[ end trace 644721052755541c ]--- This is because we started using writeback_inodes_sb() to flush delalloc when committing a transaction (when using -o flushoncommit), in order to avoid deadlocks with filesystem freeze operations. This change was made by commit ce8ea7cc6eb313 ("btrfs: don't call btrfs_start_delalloc_roots in flushoncommit"). After that change we started producing that warning, and every now and then a user reports this since the warning happens too often, it spams dmesg/syslog, and a user is unsure if this reflects any problem that might compromise the filesystem's reliability. We can not just lock the sb->s_umount semaphore before calling writeback_inodes_sb(), because that would at least deadlock with filesystem freezing, since at fs/super.c:freeze_super() sync_filesystem() is called while we are holding that semaphore in write mode, and that can trigger a transaction commit, resulting in a deadlock. It would also trigger the same type of deadlock in the unmount path. Possibly, it could also introduce some other locking dependencies that lockdep would report. To fix this call try_to_writeback_inodes_sb() instead of writeback_inodes_sb(), because that will try to read lock sb->s_umount and then will only call writeback_inodes_sb() if it was able to lock it. This is fine because the cases where it can't read lock sb->s_umount are during a filesystem unmount or during a filesystem freeze - in those cases sb->s_umount is write locked and sync_filesystem() is called, which calls writeback_inodes_sb(). In other words, in all cases where we can't take a read lock on sb->s_umount, writeback is already being triggered elsewhere. An alternative would be to call btrfs_start_delalloc_roots() with a number of pages different from LONG_MAX, for example matching the number of delalloc bytes we currently have, in which case we would end up starting all delalloc with filemap_fdatawrite_wbc() and not with an async flush via filemap_flush() - that is only possible after the rather recent commit e076ab2a2ca70a ("btrfs: shrink delalloc pages instead of full inodes"). However that creates a whole new can of worms due to new lock dependencies, which lockdep complains, like for example: [ 8948.247280] ====================================================== [ 8948.247823] WARNING: possible circular locking dependency detected [ 8948.248353] 5.17.0-rc1-btrfs-next-111 #1 Not tainted [ 8948.248786] ------------------------------------------------------ [ 8948.249320] kworker/u16:18/933570 is trying to acquire lock: [ 8948.249812] ffff9b3de1591690 (sb_internal#2){.+.+}-{0:0}, at: find_free_extent+0x141e/0x1590 [btrfs] [ 8948.250638] but task is already holding lock: [ 8948.251140] ffff9b3e09c717d8 (&root->delalloc_mutex){+.+.}-{3:3}, at: start_delalloc_inodes+0x78/0x400 [btrfs] [ 8948.252018] which lock already depends on the new lock. [ 8948.252710] the existing dependency chain (in reverse order) is: [ 8948.253343] -> #2 (&root->delalloc_mutex){+.+.}-{3:3}: [ 8948.253950] __mutex_lock+0x90/0x900 [ 8948.254354] start_delalloc_inodes+0x78/0x400 [btrfs] [ 8948.254859] btrfs_start_delalloc_roots+0x194/0x2a0 [btrfs] [ 8948.255408] btrfs_commit_transaction+0x32f/0xc00 [btrfs] [ 8948.255942] btrfs_mksubvol+0x380/0x570 [btrfs] [ 8948.256406] btrfs_mksnapshot+0x81/0xb0 [btrfs] [ 8948.256870] __btrfs_ioctl_snap_create+0x17f/0x190 [btrfs] [ 8948.257413] btrfs_ioctl_snap_create_v2+0xbb/0x140 [btrfs] [ 8948.257961] btrfs_ioctl+0x1196/0x3630 [btrfs] [ 8948.258418] __x64_sys_ioctl+0x83/0xb0 [ 8948.258793] do_syscall_64+0x3b/0xc0 [ 8948.259146] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 8948.259709] -> #1 (&fs_info->delalloc_root_mutex){+.+.}-{3:3}: [ 8948.260330] __mutex_lock+0x90/0x900 [ 8948.260692] btrfs_start_delalloc_roots+0x97/0x2a0 [btrfs] [ 8948.261234] btrfs_commit_transaction+0x32f/0xc00 [btrfs] [ 8948.261766] btrfs_set_free_space_cache_v1_active+0x38/0x60 [btrfs] [ 8948.262379] btrfs_start_pre_rw_mount+0x119/0x180 [btrfs] [ 8948.262909] open_ctree+0x1511/0x171e [btrfs] [ 8948.263359] btrfs_mount_root.cold+0x12/0xde [btrfs] [ 8948.263863] legacy_get_tree+0x30/0x50 [ 8948.264242] vfs_get_tree+0x28/0xc0 [ 8948.264594] vfs_kern_mount.part.0+0x71/0xb0 [ 8948.265017] btrfs_mount+0x11d/0x3a0 [btrfs] [ 8948.265462] legacy_get_tree+0x30/0x50 [ 8948.265851] vfs_get_tree+0x28/0xc0 [ 8948.266203] path_mount+0x2d4/0xbe0 [ 8948.266554] __x64_sys_mount+0x103/0x140 [ 8948.266940] do_syscall_64+0x3b/0xc0 [ 8948.267300] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 8948.267790] -> #0 (sb_internal#2){.+.+}-{0:0}: [ 8948.268322] __lock_acquire+0x12e8/0x2260 [ 8948.268733] lock_acquire+0xd7/0x310 [ 8948.269092] start_transaction+0x44c/0x6e0 [btrfs] [ 8948.269591] find_free_extent+0x141e/0x1590 [btrfs] [ 8948.270087] btrfs_reserve_extent+0x14b/0x280 [btrfs] [ 8948.270588] cow_file_range+0x17e/0x490 [btrfs] [ 8948.271051] btrfs_run_delalloc_range+0x345/0x7a0 [btrfs] [ 8948.271586] writepage_delalloc+0xb5/0x170 [btrfs] [ 8948.272071] __extent_writepage+0x156/0x3c0 [btrfs] [ 8948.272579] extent_write_cache_pages+0x263/0x460 [btrfs] [ 8948.273113] extent_writepages+0x76/0x130 [btrfs] [ 8948.273573] do_writepages+0xd2/0x1c0 [ 8948.273942] filemap_fdatawrite_wbc+0x68/0x90 [ 8948.274371] start_delalloc_inodes+0x17f/0x400 [btrfs] [ 8948.274876] btrfs_start_delalloc_roots+0x194/0x2a0 [btrfs] [ 8948.275417] flush_space+0x1f2/0x630 [btrfs] [ 8948.275863] btrfs_async_reclaim_data_space+0x108/0x1b0 [btrfs] [ 8948.276438] process_one_work+0x252/0x5a0 [ 8948.276829] worker_thread+0x55/0x3b0 [ 8948.277189] kthread+0xf2/0x120 [ 8948.277506] ret_from_fork+0x22/0x30 [ 8948.277868] other info that might help us debug this: [ 8948.278548] Chain exists of: sb_internal#2 --> &fs_info->delalloc_root_mutex --> &root->delalloc_mutex [ 8948.279601] Possible unsafe locking scenario: [ 8948.280102] CPU0 CPU1 [ 8948.280508] ---- ---- [ 8948.280915] lock(&root->delalloc_mutex); [ 8948.281271] lock(&fs_info->delalloc_root_mutex); [ 8948.281915] lock(&root->delalloc_mutex); [ 8948.282487] lock(sb_internal#2); [ 8948.282800] *** DEADLOCK *** [ 8948.283333] 4 locks held by kworker/u16:18/933570: [ 8948.283750] #0: ffff9b3dc00a9d48 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1d2/0x5a0 [ 8948.284609] #1: ffffa90349dafe70 ((work_completion)(&fs_info->async_data_reclaim_work)){+.+.}-{0:0}, at: process_one_work+0x1d2/0x5a0 [ 8948.285637] #2: ffff9b3e14db5040 (&fs_info->delalloc_root_mutex){+.+.}-{3:3}, at: btrfs_start_delalloc_roots+0x97/0x2a0 [btrfs] [ 8948.286674] #3: ffff9b3e09c717d8 (&root->delalloc_mutex){+.+.}-{3:3}, at: start_delalloc_inodes+0x78/0x400 [btrfs] [ 8948.287596] stack backtrace: [ 8948.287975] CPU: 3 PID: 933570 Comm: kworker/u16:18 Not tainted 5.17.0-rc1-btrfs-next-111 #1 [ 8948.288677] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 [ 8948.289649] Workqueue: events_unbound btrfs_async_reclaim_data_space [btrfs] [ 8948.290298] Call Trace: [ 8948.290517] <TASK> [ 8948.290700] dump_stack_lvl+0x59/0x73 [ 8948.291026] check_noncircular+0xf3/0x110 [ 8948.291375] ? start_transaction+0x228/0x6e0 [btrfs] [ 8948.291826] __lock_acquire+0x12e8/0x2260 [ 8948.292241] lock_acquire+0xd7/0x310 [ 8948.292714] ? find_free_extent+0x141e/0x1590 [btrfs] [ 8948.293241] ? lock_is_held_type+0xea/0x140 [ 8948.293601] start_transaction+0x44c/0x6e0 [btrfs] [ 8948.294055] ? find_free_extent+0x141e/0x1590 [btrfs] [ 8948.294518] find_free_extent+0x141e/0x1590 [btrfs] [ 8948.294957] ? _raw_spin_unlock+0x29/0x40 [ 8948.295312] ? btrfs_get_alloc_profile+0x124/0x290 [btrfs] [ 8948.295813] btrfs_reserve_extent+0x14b/0x280 [btrfs] [ 8948.296270] cow_file_range+0x17e/0x490 [btrfs] [ 8948.296691] btrfs_run_delalloc_range+0x345/0x7a0 [btrfs] [ 8948.297175] ? find_lock_delalloc_range+0x247/0x270 [btrfs] [ 8948.297678] writepage_delalloc+0xb5/0x170 [btrfs] [ 8948.298123] __extent_writepage+0x156/0x3c0 [btrfs] [ 8948.298570] extent_write_cache_pages+0x263/0x460 [btrfs] [ 8948.299061] extent_writepages+0x76/0x130 [btrfs] [ 8948.299495] do_writepages+0xd2/0x1c0 [ 8948.299817] ? sched_clock_cpu+0xd/0x110 [ 8948.300160] ? lock_release+0x155/0x4a0 [ 8948.300494] filemap_fdatawrite_wbc+0x68/0x90 [ 8948.300874] ? do_raw_spin_unlock+0x4b/0xa0 [ 8948.301243] start_delalloc_inodes+0x17f/0x400 [btrfs] [ 8948.301706] ? lock_release+0x155/0x4a0 [ 8948.302055] btrfs_start_delalloc_roots+0x194/0x2a0 [btrfs] [ 8948.302564] flush_space+0x1f2/0x630 [btrfs] [ 8948.302970] btrfs_async_reclaim_data_space+0x108/0x1b0 [btrfs] [ 8948.303510] process_one_work+0x252/0x5a0 [ 8948.303860] ? process_one_work+0x5a0/0x5a0 [ 8948.304221] worker_thread+0x55/0x3b0 [ 8948.304543] ? process_one_work+0x5a0/0x5a0 [ 8948.304904] kthread+0xf2/0x120 [ 8948.305184] ? kthread_complete_and_exit+0x20/0x20 [ 8948.305598] ret_from_fork+0x22/0x30 [ 8948.305921] </TASK> It all comes from the fact that btrfs_start_delalloc_roots() takes the delalloc_root_mutex, in the transaction commit path we are holding a read lock on one of the superblock's freeze semaphores (via sb_start_intwrite()), the async reclaim task can also do a call to btrfs_start_delalloc_roots(), which ends up triggering writeback with calls to filemap_fdatawrite_wbc(), resulting in extent allocation which in turn can call btrfs_start_transaction(), which will result in taking the freeze semaphore via sb_start_intwrite(), forming a nasty dependency on all those locks which can be taken in different orders by different code paths. So just adopt the simple approach of calling try_to_writeback_inodes_sb() at btrfs_start_delalloc_flush(). Link: https://lore.kernel.org/linux-btrfs/20220130005258.GA7465@cuci.nl/ Link: https://lore.kernel.org/linux-btrfs/43acc426-d683-d1b6-729d-c6bc4a2fff4d@gm… Link: https://lore.kernel.org/linux-btrfs/6833930a-08d7-6fbc-0141-eb9cdfd6bb4d@gm… Link: https://lore.kernel.org/linux-btrfs/20190322041731.GF16651@hungrycats.org/ Reviewed-by: Omar Sandoval <osandov(a)fb.com> Signed-off-by: Filipe Manana <fdmanana(a)suse.com> [ add more link reports ] Signed-off-by: David Sterba <dsterba(a)suse.com> Signed-off-by: Yifan Qiao <qiaoyifan4(a)huawei.com> --- fs/btrfs/transaction.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c index a73b400450ce..89117cc2cf05 100644 --- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -2019,16 +2019,24 @@ static void btrfs_cleanup_pending_block_groups(struct btrfs_trans_handle *trans) static inline int btrfs_start_delalloc_flush(struct btrfs_fs_info *fs_info) { /* - * We use writeback_inodes_sb here because if we used + * We use try_to_writeback_inodes_sb() here because if we used * btrfs_start_delalloc_roots we would deadlock with fs freeze. * Currently are holding the fs freeze lock, if we do an async flush * we'll do btrfs_join_transaction() and deadlock because we need to * wait for the fs freeze lock. Using the direct flushing we benefit * from already being in a transaction and our join_transaction doesn't * have to re-take the fs freeze lock. + * + * Note that try_to_writeback_inodes_sb() will only trigger writeback + * if it can read lock sb->s_umount. It will always be able to lock it, + * except when the filesystem is being unmounted or being frozen, but in + * those cases sync_filesystem() is called, which results in calling + * writeback_inodes_sb() while holding a write lock on sb->s_umount. + * Note that we don't call writeback_inodes_sb() directly, because it + * will emit a warning if sb->s_umount is not locked. */ if (btrfs_test_opt(fs_info, FLUSHONCOMMIT)) - writeback_inodes_sb(fs_info->sb, WB_REASON_SYNC); + try_to_writeback_inodes_sb(fs_info->sb, WB_REASON_SYNC); return 0; } -- 2.39.2

2 1

[PATCH openEuler-22.03-LTS-SP1] btrfs: get rid of warning on transaction commit when using flushoncommit
by Yifan Qiao 26 Aug '24

26 Aug '24

From: Filipe Manana <fdmanana(a)suse.com> mainline inclusion from mainline-v5.17-rc5 commit a0f0cf8341e34e5d2265bfd3a7ad68342da1e2aa category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IALPT4 CVE: CVE-2022-48920 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?… -------------------------------- When using the flushoncommit mount option, during almost every transaction commit we trigger a warning from __writeback_inodes_sb_nr(): $ cat fs/fs-writeback.c: (...) static void __writeback_inodes_sb_nr(struct super_block *sb, ... { (...) WARN_ON(!rwsem_is_locked(&sb->s_umount)); (...) } (...) The trace produced in dmesg looks like the following: [947.473890] WARNING: CPU: 5 PID: 930 at fs/fs-writeback.c:2610 __writeback_inodes_sb_nr+0x7e/0xb3 [947.481623] Modules linked in: nfsd nls_cp437 cifs asn1_decoder cifs_arc4 fscache cifs_md4 ipmi_ssif [947.489571] CPU: 5 PID: 930 Comm: btrfs-transacti Not tainted 95.16.3-srb-asrock-00001-g36437ad63879 #186 [947.497969] RIP: 0010:__writeback_inodes_sb_nr+0x7e/0xb3 [947.502097] Code: 24 10 4c 89 44 24 18 c6 (...) [947.519760] RSP: 0018:ffffc90000777e10 EFLAGS: 00010246 [947.523818] RAX: 0000000000000000 RBX: 0000000000963300 RCX: 0000000000000000 [947.529765] RDX: 0000000000000000 RSI: 000000000000fa51 RDI: ffffc90000777e50 [947.535740] RBP: ffff888101628a90 R08: ffff888100955800 R09: ffff888100956000 [947.541701] R10: 0000000000000002 R11: 0000000000000001 R12: ffff888100963488 [947.547645] R13: ffff888100963000 R14: ffff888112fb7200 R15: ffff888100963460 [947.553621] FS: 0000000000000000(0000) GS:ffff88841fd40000(0000) knlGS:0000000000000000 [947.560537] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [947.565122] CR2: 0000000008be50c4 CR3: 000000000220c000 CR4: 00000000001006e0 [947.571072] Call Trace: [947.572354] <TASK> [947.573266] btrfs_commit_transaction+0x1f1/0x998 [947.576785] ? start_transaction+0x3ab/0x44e [947.579867] ? schedule_timeout+0x8a/0xdd [947.582716] transaction_kthread+0xe9/0x156 [947.585721] ? btrfs_cleanup_transaction.isra.0+0x407/0x407 [947.590104] kthread+0x131/0x139 [947.592168] ? set_kthread_struct+0x32/0x32 [947.595174] ret_from_fork+0x22/0x30 [947.597561] </TASK> [947.598553] ---[ end trace 644721052755541c ]--- This is because we started using writeback_inodes_sb() to flush delalloc when committing a transaction (when using -o flushoncommit), in order to avoid deadlocks with filesystem freeze operations. This change was made by commit ce8ea7cc6eb313 ("btrfs: don't call btrfs_start_delalloc_roots in flushoncommit"). After that change we started producing that warning, and every now and then a user reports this since the warning happens too often, it spams dmesg/syslog, and a user is unsure if this reflects any problem that might compromise the filesystem's reliability. We can not just lock the sb->s_umount semaphore before calling writeback_inodes_sb(), because that would at least deadlock with filesystem freezing, since at fs/super.c:freeze_super() sync_filesystem() is called while we are holding that semaphore in write mode, and that can trigger a transaction commit, resulting in a deadlock. It would also trigger the same type of deadlock in the unmount path. Possibly, it could also introduce some other locking dependencies that lockdep would report. To fix this call try_to_writeback_inodes_sb() instead of writeback_inodes_sb(), because that will try to read lock sb->s_umount and then will only call writeback_inodes_sb() if it was able to lock it. This is fine because the cases where it can't read lock sb->s_umount are during a filesystem unmount or during a filesystem freeze - in those cases sb->s_umount is write locked and sync_filesystem() is called, which calls writeback_inodes_sb(). In other words, in all cases where we can't take a read lock on sb->s_umount, writeback is already being triggered elsewhere. An alternative would be to call btrfs_start_delalloc_roots() with a number of pages different from LONG_MAX, for example matching the number of delalloc bytes we currently have, in which case we would end up starting all delalloc with filemap_fdatawrite_wbc() and not with an async flush via filemap_flush() - that is only possible after the rather recent commit e076ab2a2ca70a ("btrfs: shrink delalloc pages instead of full inodes"). However that creates a whole new can of worms due to new lock dependencies, which lockdep complains, like for example: [ 8948.247280] ====================================================== [ 8948.247823] WARNING: possible circular locking dependency detected [ 8948.248353] 5.17.0-rc1-btrfs-next-111 #1 Not tainted [ 8948.248786] ------------------------------------------------------ [ 8948.249320] kworker/u16:18/933570 is trying to acquire lock: [ 8948.249812] ffff9b3de1591690 (sb_internal#2){.+.+}-{0:0}, at: find_free_extent+0x141e/0x1590 [btrfs] [ 8948.250638] but task is already holding lock: [ 8948.251140] ffff9b3e09c717d8 (&root->delalloc_mutex){+.+.}-{3:3}, at: start_delalloc_inodes+0x78/0x400 [btrfs] [ 8948.252018] which lock already depends on the new lock. [ 8948.252710] the existing dependency chain (in reverse order) is: [ 8948.253343] -> #2 (&root->delalloc_mutex){+.+.}-{3:3}: [ 8948.253950] __mutex_lock+0x90/0x900 [ 8948.254354] start_delalloc_inodes+0x78/0x400 [btrfs] [ 8948.254859] btrfs_start_delalloc_roots+0x194/0x2a0 [btrfs] [ 8948.255408] btrfs_commit_transaction+0x32f/0xc00 [btrfs] [ 8948.255942] btrfs_mksubvol+0x380/0x570 [btrfs] [ 8948.256406] btrfs_mksnapshot+0x81/0xb0 [btrfs] [ 8948.256870] __btrfs_ioctl_snap_create+0x17f/0x190 [btrfs] [ 8948.257413] btrfs_ioctl_snap_create_v2+0xbb/0x140 [btrfs] [ 8948.257961] btrfs_ioctl+0x1196/0x3630 [btrfs] [ 8948.258418] __x64_sys_ioctl+0x83/0xb0 [ 8948.258793] do_syscall_64+0x3b/0xc0 [ 8948.259146] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 8948.259709] -> #1 (&fs_info->delalloc_root_mutex){+.+.}-{3:3}: [ 8948.260330] __mutex_lock+0x90/0x900 [ 8948.260692] btrfs_start_delalloc_roots+0x97/0x2a0 [btrfs] [ 8948.261234] btrfs_commit_transaction+0x32f/0xc00 [btrfs] [ 8948.261766] btrfs_set_free_space_cache_v1_active+0x38/0x60 [btrfs] [ 8948.262379] btrfs_start_pre_rw_mount+0x119/0x180 [btrfs] [ 8948.262909] open_ctree+0x1511/0x171e [btrfs] [ 8948.263359] btrfs_mount_root.cold+0x12/0xde [btrfs] [ 8948.263863] legacy_get_tree+0x30/0x50 [ 8948.264242] vfs_get_tree+0x28/0xc0 [ 8948.264594] vfs_kern_mount.part.0+0x71/0xb0 [ 8948.265017] btrfs_mount+0x11d/0x3a0 [btrfs] [ 8948.265462] legacy_get_tree+0x30/0x50 [ 8948.265851] vfs_get_tree+0x28/0xc0 [ 8948.266203] path_mount+0x2d4/0xbe0 [ 8948.266554] __x64_sys_mount+0x103/0x140 [ 8948.266940] do_syscall_64+0x3b/0xc0 [ 8948.267300] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 8948.267790] -> #0 (sb_internal#2){.+.+}-{0:0}: [ 8948.268322] __lock_acquire+0x12e8/0x2260 [ 8948.268733] lock_acquire+0xd7/0x310 [ 8948.269092] start_transaction+0x44c/0x6e0 [btrfs] [ 8948.269591] find_free_extent+0x141e/0x1590 [btrfs] [ 8948.270087] btrfs_reserve_extent+0x14b/0x280 [btrfs] [ 8948.270588] cow_file_range+0x17e/0x490 [btrfs] [ 8948.271051] btrfs_run_delalloc_range+0x345/0x7a0 [btrfs] [ 8948.271586] writepage_delalloc+0xb5/0x170 [btrfs] [ 8948.272071] __extent_writepage+0x156/0x3c0 [btrfs] [ 8948.272579] extent_write_cache_pages+0x263/0x460 [btrfs] [ 8948.273113] extent_writepages+0x76/0x130 [btrfs] [ 8948.273573] do_writepages+0xd2/0x1c0 [ 8948.273942] filemap_fdatawrite_wbc+0x68/0x90 [ 8948.274371] start_delalloc_inodes+0x17f/0x400 [btrfs] [ 8948.274876] btrfs_start_delalloc_roots+0x194/0x2a0 [btrfs] [ 8948.275417] flush_space+0x1f2/0x630 [btrfs] [ 8948.275863] btrfs_async_reclaim_data_space+0x108/0x1b0 [btrfs] [ 8948.276438] process_one_work+0x252/0x5a0 [ 8948.276829] worker_thread+0x55/0x3b0 [ 8948.277189] kthread+0xf2/0x120 [ 8948.277506] ret_from_fork+0x22/0x30 [ 8948.277868] other info that might help us debug this: [ 8948.278548] Chain exists of: sb_internal#2 --> &fs_info->delalloc_root_mutex --> &root->delalloc_mutex [ 8948.279601] Possible unsafe locking scenario: [ 8948.280102] CPU0 CPU1 [ 8948.280508] ---- ---- [ 8948.280915] lock(&root->delalloc_mutex); [ 8948.281271] lock(&fs_info->delalloc_root_mutex); [ 8948.281915] lock(&root->delalloc_mutex); [ 8948.282487] lock(sb_internal#2); [ 8948.282800] *** DEADLOCK *** [ 8948.283333] 4 locks held by kworker/u16:18/933570: [ 8948.283750] #0: ffff9b3dc00a9d48 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1d2/0x5a0 [ 8948.284609] #1: ffffa90349dafe70 ((work_completion)(&fs_info->async_data_reclaim_work)){+.+.}-{0:0}, at: process_one_work+0x1d2/0x5a0 [ 8948.285637] #2: ffff9b3e14db5040 (&fs_info->delalloc_root_mutex){+.+.}-{3:3}, at: btrfs_start_delalloc_roots+0x97/0x2a0 [btrfs] [ 8948.286674] #3: ffff9b3e09c717d8 (&root->delalloc_mutex){+.+.}-{3:3}, at: start_delalloc_inodes+0x78/0x400 [btrfs] [ 8948.287596] stack backtrace: [ 8948.287975] CPU: 3 PID: 933570 Comm: kworker/u16:18 Not tainted 5.17.0-rc1-btrfs-next-111 #1 [ 8948.288677] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 [ 8948.289649] Workqueue: events_unbound btrfs_async_reclaim_data_space [btrfs] [ 8948.290298] Call Trace: [ 8948.290517] <TASK> [ 8948.290700] dump_stack_lvl+0x59/0x73 [ 8948.291026] check_noncircular+0xf3/0x110 [ 8948.291375] ? start_transaction+0x228/0x6e0 [btrfs] [ 8948.291826] __lock_acquire+0x12e8/0x2260 [ 8948.292241] lock_acquire+0xd7/0x310 [ 8948.292714] ? find_free_extent+0x141e/0x1590 [btrfs] [ 8948.293241] ? lock_is_held_type+0xea/0x140 [ 8948.293601] start_transaction+0x44c/0x6e0 [btrfs] [ 8948.294055] ? find_free_extent+0x141e/0x1590 [btrfs] [ 8948.294518] find_free_extent+0x141e/0x1590 [btrfs] [ 8948.294957] ? _raw_spin_unlock+0x29/0x40 [ 8948.295312] ? btrfs_get_alloc_profile+0x124/0x290 [btrfs] [ 8948.295813] btrfs_reserve_extent+0x14b/0x280 [btrfs] [ 8948.296270] cow_file_range+0x17e/0x490 [btrfs] [ 8948.296691] btrfs_run_delalloc_range+0x345/0x7a0 [btrfs] [ 8948.297175] ? find_lock_delalloc_range+0x247/0x270 [btrfs] [ 8948.297678] writepage_delalloc+0xb5/0x170 [btrfs] [ 8948.298123] __extent_writepage+0x156/0x3c0 [btrfs] [ 8948.298570] extent_write_cache_pages+0x263/0x460 [btrfs] [ 8948.299061] extent_writepages+0x76/0x130 [btrfs] [ 8948.299495] do_writepages+0xd2/0x1c0 [ 8948.299817] ? sched_clock_cpu+0xd/0x110 [ 8948.300160] ? lock_release+0x155/0x4a0 [ 8948.300494] filemap_fdatawrite_wbc+0x68/0x90 [ 8948.300874] ? do_raw_spin_unlock+0x4b/0xa0 [ 8948.301243] start_delalloc_inodes+0x17f/0x400 [btrfs] [ 8948.301706] ? lock_release+0x155/0x4a0 [ 8948.302055] btrfs_start_delalloc_roots+0x194/0x2a0 [btrfs] [ 8948.302564] flush_space+0x1f2/0x630 [btrfs] [ 8948.302970] btrfs_async_reclaim_data_space+0x108/0x1b0 [btrfs] [ 8948.303510] process_one_work+0x252/0x5a0 [ 8948.303860] ? process_one_work+0x5a0/0x5a0 [ 8948.304221] worker_thread+0x55/0x3b0 [ 8948.304543] ? process_one_work+0x5a0/0x5a0 [ 8948.304904] kthread+0xf2/0x120 [ 8948.305184] ? kthread_complete_and_exit+0x20/0x20 [ 8948.305598] ret_from_fork+0x22/0x30 [ 8948.305921] </TASK> It all comes from the fact that btrfs_start_delalloc_roots() takes the delalloc_root_mutex, in the transaction commit path we are holding a read lock on one of the superblock's freeze semaphores (via sb_start_intwrite()), the async reclaim task can also do a call to btrfs_start_delalloc_roots(), which ends up triggering writeback with calls to filemap_fdatawrite_wbc(), resulting in extent allocation which in turn can call btrfs_start_transaction(), which will result in taking the freeze semaphore via sb_start_intwrite(), forming a nasty dependency on all those locks which can be taken in different orders by different code paths. So just adopt the simple approach of calling try_to_writeback_inodes_sb() at btrfs_start_delalloc_flush(). Link: https://lore.kernel.org/linux-btrfs/20220130005258.GA7465@cuci.nl/ Link: https://lore.kernel.org/linux-btrfs/43acc426-d683-d1b6-729d-c6bc4a2fff4d@gm… Link: https://lore.kernel.org/linux-btrfs/6833930a-08d7-6fbc-0141-eb9cdfd6bb4d@gm… Link: https://lore.kernel.org/linux-btrfs/20190322041731.GF16651@hungrycats.org/ Reviewed-by: Omar Sandoval <osandov(a)fb.com> Signed-off-by: Filipe Manana <fdmanana(a)suse.com> [ add more link reports ] Signed-off-by: David Sterba <dsterba(a)suse.com> Signed-off-by: Yifan Qiao <qiaoyifan4(a)huawei.com> --- fs/btrfs/transaction.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c index 897ea85e04e4..a6ddf91d5c40 100644 --- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -2012,16 +2012,24 @@ static void btrfs_cleanup_pending_block_groups(struct btrfs_trans_handle *trans) static inline int btrfs_start_delalloc_flush(struct btrfs_fs_info *fs_info) { /* - * We use writeback_inodes_sb here because if we used + * We use try_to_writeback_inodes_sb() here because if we used * btrfs_start_delalloc_roots we would deadlock with fs freeze. * Currently are holding the fs freeze lock, if we do an async flush * we'll do btrfs_join_transaction() and deadlock because we need to * wait for the fs freeze lock. Using the direct flushing we benefit * from already being in a transaction and our join_transaction doesn't * have to re-take the fs freeze lock. + * + * Note that try_to_writeback_inodes_sb() will only trigger writeback + * if it can read lock sb->s_umount. It will always be able to lock it, + * except when the filesystem is being unmounted or being frozen, but in + * those cases sync_filesystem() is called, which results in calling + * writeback_inodes_sb() while holding a write lock on sb->s_umount. + * Note that we don't call writeback_inodes_sb() directly, because it + * will emit a warning if sb->s_umount is not locked. */ if (btrfs_test_opt(fs_info, FLUSHONCOMMIT)) - writeback_inodes_sb(fs_info->sb, WB_REASON_SYNC); + try_to_writeback_inodes_sb(fs_info->sb, WB_REASON_SYNC); return 0; } -- 2.39.2

2 1

[PATCH openEuler-22.03-LTS-SP1] usb: vhci-hcd: Do not drop references before new references are gained
by Zheng Yejian 26 Aug '24

26 Aug '24

From: Oliver Neukum <oneukum(a)suse.com> stable inclusion from stable-v5.10.224 commit 4dacdb9720aaab10b6be121eae55820174d97174 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAM59O CVE: CVE-2024-43883 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id… -------------------------------- commit afdcfd3d6fcdeca2735ca8d994c5f2d24a368f0a upstream. At a few places the driver carries stale pointers to references that can still be used. Make sure that does not happen. This strictly speaking closes ZDI-CAN-22273, though there may be similar races in the driver. Signed-off-by: Oliver Neukum <oneukum(a)suse.com> Cc: stable <stable(a)kernel.org> Acked-by: Shuah Khan <skhan(a)linuxfoundation.org> Link: https://lore.kernel.org/r/20240709113851.14691-1-oneukum@suse.com Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> Signed-off-by: Zheng Yejian <zhengyejian1(a)huawei.com> --- drivers/usb/usbip/vhci_hcd.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/drivers/usb/usbip/vhci_hcd.c b/drivers/usb/usbip/vhci_hcd.c index b07b2925ff78..affcb928771d 100644 --- a/drivers/usb/usbip/vhci_hcd.c +++ b/drivers/usb/usbip/vhci_hcd.c @@ -745,6 +745,7 @@ static int vhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb, gfp_t mem_flag * */ if (usb_pipedevice(urb->pipe) == 0) { + struct usb_device *old; __u8 type = usb_pipetype(urb->pipe); struct usb_ctrlrequest *ctrlreq = (struct usb_ctrlrequest *) urb->setup_packet; @@ -755,14 +756,15 @@ static int vhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb, gfp_t mem_flag goto no_need_xmit; } + old = vdev->udev; switch (ctrlreq->bRequest) { case USB_REQ_SET_ADDRESS: /* set_address may come when a device is reset */ dev_info(dev, "SetAddress Request (%d) to port %d\n", ctrlreq->wValue, vdev->rhport); - usb_put_dev(vdev->udev); vdev->udev = usb_get_dev(urb->dev); + usb_put_dev(old); spin_lock(&vdev->ud.lock); vdev->ud.status = VDEV_ST_USED; @@ -781,8 +783,8 @@ static int vhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb, gfp_t mem_flag usbip_dbg_vhci_hc( "Not yet?:Get_Descriptor to device 0 (get max pipe size)\n"); - usb_put_dev(vdev->udev); vdev->udev = usb_get_dev(urb->dev); + usb_put_dev(old); goto out; default: @@ -1095,6 +1097,7 @@ static void vhci_shutdown_connection(struct usbip_device *ud) static void vhci_device_reset(struct usbip_device *ud) { struct vhci_device *vdev = container_of(ud, struct vhci_device, ud); + struct usb_device *old = vdev->udev; unsigned long flags; spin_lock_irqsave(&ud->lock, flags); @@ -1102,8 +1105,8 @@ static void vhci_device_reset(struct usbip_device *ud) vdev->speed = 0; vdev->devid = 0; - usb_put_dev(vdev->udev); vdev->udev = NULL; + usb_put_dev(old); if (ud->tcp_socket) { sockfd_put(ud->tcp_socket); -- 2.25.1

2 1

[PATCH OLK-5.10] btrfs: get rid of warning on transaction commit when using flushoncommit
by Yifan Qiao 26 Aug '24

26 Aug '24

From: Filipe Manana <fdmanana(a)suse.com> mainline inclusion from mainline-v5.17-rc5 commit a0f0cf8341e34e5d2265bfd3a7ad68342da1e2aa category: bugfix bugzilla: 190271 CVE: CVE-2022-48920 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?… -------------------------------- When using the flushoncommit mount option, during almost every transaction commit we trigger a warning from __writeback_inodes_sb_nr(): $ cat fs/fs-writeback.c: (...) static void __writeback_inodes_sb_nr(struct super_block *sb, ... { (...) WARN_ON(!rwsem_is_locked(&sb->s_umount)); (...) } (...) The trace produced in dmesg looks like the following: [947.473890] WARNING: CPU: 5 PID: 930 at fs/fs-writeback.c:2610 __writeback_inodes_sb_nr+0x7e/0xb3 [947.481623] Modules linked in: nfsd nls_cp437 cifs asn1_decoder cifs_arc4 fscache cifs_md4 ipmi_ssif [947.489571] CPU: 5 PID: 930 Comm: btrfs-transacti Not tainted 95.16.3-srb-asrock-00001-g36437ad63879 #186 [947.497969] RIP: 0010:__writeback_inodes_sb_nr+0x7e/0xb3 [947.502097] Code: 24 10 4c 89 44 24 18 c6 (...) [947.519760] RSP: 0018:ffffc90000777e10 EFLAGS: 00010246 [947.523818] RAX: 0000000000000000 RBX: 0000000000963300 RCX: 0000000000000000 [947.529765] RDX: 0000000000000000 RSI: 000000000000fa51 RDI: ffffc90000777e50 [947.535740] RBP: ffff888101628a90 R08: ffff888100955800 R09: ffff888100956000 [947.541701] R10: 0000000000000002 R11: 0000000000000001 R12: ffff888100963488 [947.547645] R13: ffff888100963000 R14: ffff888112fb7200 R15: ffff888100963460 [947.553621] FS: 0000000000000000(0000) GS:ffff88841fd40000(0000) knlGS:0000000000000000 [947.560537] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [947.565122] CR2: 0000000008be50c4 CR3: 000000000220c000 CR4: 00000000001006e0 [947.571072] Call Trace: [947.572354] <TASK> [947.573266] btrfs_commit_transaction+0x1f1/0x998 [947.576785] ? start_transaction+0x3ab/0x44e [947.579867] ? schedule_timeout+0x8a/0xdd [947.582716] transaction_kthread+0xe9/0x156 [947.585721] ? btrfs_cleanup_transaction.isra.0+0x407/0x407 [947.590104] kthread+0x131/0x139 [947.592168] ? set_kthread_struct+0x32/0x32 [947.595174] ret_from_fork+0x22/0x30 [947.597561] </TASK> [947.598553] ---[ end trace 644721052755541c ]--- This is because we started using writeback_inodes_sb() to flush delalloc when committing a transaction (when using -o flushoncommit), in order to avoid deadlocks with filesystem freeze operations. This change was made by commit ce8ea7cc6eb313 ("btrfs: don't call btrfs_start_delalloc_roots in flushoncommit"). After that change we started producing that warning, and every now and then a user reports this since the warning happens too often, it spams dmesg/syslog, and a user is unsure if this reflects any problem that might compromise the filesystem's reliability. We can not just lock the sb->s_umount semaphore before calling writeback_inodes_sb(), because that would at least deadlock with filesystem freezing, since at fs/super.c:freeze_super() sync_filesystem() is called while we are holding that semaphore in write mode, and that can trigger a transaction commit, resulting in a deadlock. It would also trigger the same type of deadlock in the unmount path. Possibly, it could also introduce some other locking dependencies that lockdep would report. To fix this call try_to_writeback_inodes_sb() instead of writeback_inodes_sb(), because that will try to read lock sb->s_umount and then will only call writeback_inodes_sb() if it was able to lock it. This is fine because the cases where it can't read lock sb->s_umount are during a filesystem unmount or during a filesystem freeze - in those cases sb->s_umount is write locked and sync_filesystem() is called, which calls writeback_inodes_sb(). In other words, in all cases where we can't take a read lock on sb->s_umount, writeback is already being triggered elsewhere. An alternative would be to call btrfs_start_delalloc_roots() with a number of pages different from LONG_MAX, for example matching the number of delalloc bytes we currently have, in which case we would end up starting all delalloc with filemap_fdatawrite_wbc() and not with an async flush via filemap_flush() - that is only possible after the rather recent commit e076ab2a2ca70a ("btrfs: shrink delalloc pages instead of full inodes"). However that creates a whole new can of worms due to new lock dependencies, which lockdep complains, like for example: [ 8948.247280] ====================================================== [ 8948.247823] WARNING: possible circular locking dependency detected [ 8948.248353] 5.17.0-rc1-btrfs-next-111 #1 Not tainted [ 8948.248786] ------------------------------------------------------ [ 8948.249320] kworker/u16:18/933570 is trying to acquire lock: [ 8948.249812] ffff9b3de1591690 (sb_internal#2){.+.+}-{0:0}, at: find_free_extent+0x141e/0x1590 [btrfs] [ 8948.250638] but task is already holding lock: [ 8948.251140] ffff9b3e09c717d8 (&root->delalloc_mutex){+.+.}-{3:3}, at: start_delalloc_inodes+0x78/0x400 [btrfs] [ 8948.252018] which lock already depends on the new lock. [ 8948.252710] the existing dependency chain (in reverse order) is: [ 8948.253343] -> #2 (&root->delalloc_mutex){+.+.}-{3:3}: [ 8948.253950] __mutex_lock+0x90/0x900 [ 8948.254354] start_delalloc_inodes+0x78/0x400 [btrfs] [ 8948.254859] btrfs_start_delalloc_roots+0x194/0x2a0 [btrfs] [ 8948.255408] btrfs_commit_transaction+0x32f/0xc00 [btrfs] [ 8948.255942] btrfs_mksubvol+0x380/0x570 [btrfs] [ 8948.256406] btrfs_mksnapshot+0x81/0xb0 [btrfs] [ 8948.256870] __btrfs_ioctl_snap_create+0x17f/0x190 [btrfs] [ 8948.257413] btrfs_ioctl_snap_create_v2+0xbb/0x140 [btrfs] [ 8948.257961] btrfs_ioctl+0x1196/0x3630 [btrfs] [ 8948.258418] __x64_sys_ioctl+0x83/0xb0 [ 8948.258793] do_syscall_64+0x3b/0xc0 [ 8948.259146] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 8948.259709] -> #1 (&fs_info->delalloc_root_mutex){+.+.}-{3:3}: [ 8948.260330] __mutex_lock+0x90/0x900 [ 8948.260692] btrfs_start_delalloc_roots+0x97/0x2a0 [btrfs] [ 8948.261234] btrfs_commit_transaction+0x32f/0xc00 [btrfs] [ 8948.261766] btrfs_set_free_space_cache_v1_active+0x38/0x60 [btrfs] [ 8948.262379] btrfs_start_pre_rw_mount+0x119/0x180 [btrfs] [ 8948.262909] open_ctree+0x1511/0x171e [btrfs] [ 8948.263359] btrfs_mount_root.cold+0x12/0xde [btrfs] [ 8948.263863] legacy_get_tree+0x30/0x50 [ 8948.264242] vfs_get_tree+0x28/0xc0 [ 8948.264594] vfs_kern_mount.part.0+0x71/0xb0 [ 8948.265017] btrfs_mount+0x11d/0x3a0 [btrfs] [ 8948.265462] legacy_get_tree+0x30/0x50 [ 8948.265851] vfs_get_tree+0x28/0xc0 [ 8948.266203] path_mount+0x2d4/0xbe0 [ 8948.266554] __x64_sys_mount+0x103/0x140 [ 8948.266940] do_syscall_64+0x3b/0xc0 [ 8948.267300] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 8948.267790] -> #0 (sb_internal#2){.+.+}-{0:0}: [ 8948.268322] __lock_acquire+0x12e8/0x2260 [ 8948.268733] lock_acquire+0xd7/0x310 [ 8948.269092] start_transaction+0x44c/0x6e0 [btrfs] [ 8948.269591] find_free_extent+0x141e/0x1590 [btrfs] [ 8948.270087] btrfs_reserve_extent+0x14b/0x280 [btrfs] [ 8948.270588] cow_file_range+0x17e/0x490 [btrfs] [ 8948.271051] btrfs_run_delalloc_range+0x345/0x7a0 [btrfs] [ 8948.271586] writepage_delalloc+0xb5/0x170 [btrfs] [ 8948.272071] __extent_writepage+0x156/0x3c0 [btrfs] [ 8948.272579] extent_write_cache_pages+0x263/0x460 [btrfs] [ 8948.273113] extent_writepages+0x76/0x130 [btrfs] [ 8948.273573] do_writepages+0xd2/0x1c0 [ 8948.273942] filemap_fdatawrite_wbc+0x68/0x90 [ 8948.274371] start_delalloc_inodes+0x17f/0x400 [btrfs] [ 8948.274876] btrfs_start_delalloc_roots+0x194/0x2a0 [btrfs] [ 8948.275417] flush_space+0x1f2/0x630 [btrfs] [ 8948.275863] btrfs_async_reclaim_data_space+0x108/0x1b0 [btrfs] [ 8948.276438] process_one_work+0x252/0x5a0 [ 8948.276829] worker_thread+0x55/0x3b0 [ 8948.277189] kthread+0xf2/0x120 [ 8948.277506] ret_from_fork+0x22/0x30 [ 8948.277868] other info that might help us debug this: [ 8948.278548] Chain exists of: sb_internal#2 --> &fs_info->delalloc_root_mutex --> &root->delalloc_mutex [ 8948.279601] Possible unsafe locking scenario: [ 8948.280102] CPU0 CPU1 [ 8948.280508] ---- ---- [ 8948.280915] lock(&root->delalloc_mutex); [ 8948.281271] lock(&fs_info->delalloc_root_mutex); [ 8948.281915] lock(&root->delalloc_mutex); [ 8948.282487] lock(sb_internal#2); [ 8948.282800] *** DEADLOCK *** [ 8948.283333] 4 locks held by kworker/u16:18/933570: [ 8948.283750] #0: ffff9b3dc00a9d48 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1d2/0x5a0 [ 8948.284609] #1: ffffa90349dafe70 ((work_completion)(&fs_info->async_data_reclaim_work)){+.+.}-{0:0}, at: process_one_work+0x1d2/0x5a0 [ 8948.285637] #2: ffff9b3e14db5040 (&fs_info->delalloc_root_mutex){+.+.}-{3:3}, at: btrfs_start_delalloc_roots+0x97/0x2a0 [btrfs] [ 8948.286674] #3: ffff9b3e09c717d8 (&root->delalloc_mutex){+.+.}-{3:3}, at: start_delalloc_inodes+0x78/0x400 [btrfs] [ 8948.287596] stack backtrace: [ 8948.287975] CPU: 3 PID: 933570 Comm: kworker/u16:18 Not tainted 5.17.0-rc1-btrfs-next-111 #1 [ 8948.288677] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 [ 8948.289649] Workqueue: events_unbound btrfs_async_reclaim_data_space [btrfs] [ 8948.290298] Call Trace: [ 8948.290517] <TASK> [ 8948.290700] dump_stack_lvl+0x59/0x73 [ 8948.291026] check_noncircular+0xf3/0x110 [ 8948.291375] ? start_transaction+0x228/0x6e0 [btrfs] [ 8948.291826] __lock_acquire+0x12e8/0x2260 [ 8948.292241] lock_acquire+0xd7/0x310 [ 8948.292714] ? find_free_extent+0x141e/0x1590 [btrfs] [ 8948.293241] ? lock_is_held_type+0xea/0x140 [ 8948.293601] start_transaction+0x44c/0x6e0 [btrfs] [ 8948.294055] ? find_free_extent+0x141e/0x1590 [btrfs] [ 8948.294518] find_free_extent+0x141e/0x1590 [btrfs] [ 8948.294957] ? _raw_spin_unlock+0x29/0x40 [ 8948.295312] ? btrfs_get_alloc_profile+0x124/0x290 [btrfs] [ 8948.295813] btrfs_reserve_extent+0x14b/0x280 [btrfs] [ 8948.296270] cow_file_range+0x17e/0x490 [btrfs] [ 8948.296691] btrfs_run_delalloc_range+0x345/0x7a0 [btrfs] [ 8948.297175] ? find_lock_delalloc_range+0x247/0x270 [btrfs] [ 8948.297678] writepage_delalloc+0xb5/0x170 [btrfs] [ 8948.298123] __extent_writepage+0x156/0x3c0 [btrfs] [ 8948.298570] extent_write_cache_pages+0x263/0x460 [btrfs] [ 8948.299061] extent_writepages+0x76/0x130 [btrfs] [ 8948.299495] do_writepages+0xd2/0x1c0 [ 8948.299817] ? sched_clock_cpu+0xd/0x110 [ 8948.300160] ? lock_release+0x155/0x4a0 [ 8948.300494] filemap_fdatawrite_wbc+0x68/0x90 [ 8948.300874] ? do_raw_spin_unlock+0x4b/0xa0 [ 8948.301243] start_delalloc_inodes+0x17f/0x400 [btrfs] [ 8948.301706] ? lock_release+0x155/0x4a0 [ 8948.302055] btrfs_start_delalloc_roots+0x194/0x2a0 [btrfs] [ 8948.302564] flush_space+0x1f2/0x630 [btrfs] [ 8948.302970] btrfs_async_reclaim_data_space+0x108/0x1b0 [btrfs] [ 8948.303510] process_one_work+0x252/0x5a0 [ 8948.303860] ? process_one_work+0x5a0/0x5a0 [ 8948.304221] worker_thread+0x55/0x3b0 [ 8948.304543] ? process_one_work+0x5a0/0x5a0 [ 8948.304904] kthread+0xf2/0x120 [ 8948.305184] ? kthread_complete_and_exit+0x20/0x20 [ 8948.305598] ret_from_fork+0x22/0x30 [ 8948.305921] </TASK> It all comes from the fact that btrfs_start_delalloc_roots() takes the delalloc_root_mutex, in the transaction commit path we are holding a read lock on one of the superblock's freeze semaphores (via sb_start_intwrite()), the async reclaim task can also do a call to btrfs_start_delalloc_roots(), which ends up triggering writeback with calls to filemap_fdatawrite_wbc(), resulting in extent allocation which in turn can call btrfs_start_transaction(), which will result in taking the freeze semaphore via sb_start_intwrite(), forming a nasty dependency on all those locks which can be taken in different orders by different code paths. So just adopt the simple approach of calling try_to_writeback_inodes_sb() at btrfs_start_delalloc_flush(). Link: https://lore.kernel.org/linux-btrfs/20220130005258.GA7465@cuci.nl/ Link: https://lore.kernel.org/linux-btrfs/43acc426-d683-d1b6-729d-c6bc4a2fff4d@gm… Link: https://lore.kernel.org/linux-btrfs/6833930a-08d7-6fbc-0141-eb9cdfd6bb4d@gm… Link: https://lore.kernel.org/linux-btrfs/20190322041731.GF16651@hungrycats.org/ Reviewed-by: Omar Sandoval <osandov(a)fb.com> Signed-off-by: Filipe Manana <fdmanana(a)suse.com> [ add more link reports ] Signed-off-by: David Sterba <dsterba(a)suse.com> Signed-off-by: Yifan Qiao <qiaoyifan4(a)huawei.com> --- fs/btrfs/transaction.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c index a73b400450ce..89117cc2cf05 100644 --- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -2019,16 +2019,24 @@ static void btrfs_cleanup_pending_block_groups(struct btrfs_trans_handle *trans) static inline int btrfs_start_delalloc_flush(struct btrfs_fs_info *fs_info) { /* - * We use writeback_inodes_sb here because if we used + * We use try_to_writeback_inodes_sb() here because if we used * btrfs_start_delalloc_roots we would deadlock with fs freeze. * Currently are holding the fs freeze lock, if we do an async flush * we'll do btrfs_join_transaction() and deadlock because we need to * wait for the fs freeze lock. Using the direct flushing we benefit * from already being in a transaction and our join_transaction doesn't * have to re-take the fs freeze lock. + * + * Note that try_to_writeback_inodes_sb() will only trigger writeback + * if it can read lock sb->s_umount. It will always be able to lock it, + * except when the filesystem is being unmounted or being frozen, but in + * those cases sync_filesystem() is called, which results in calling + * writeback_inodes_sb() while holding a write lock on sb->s_umount. + * Note that we don't call writeback_inodes_sb() directly, because it + * will emit a warning if sb->s_umount is not locked. */ if (btrfs_test_opt(fs_info, FLUSHONCOMMIT)) - writeback_inodes_sb(fs_info->sb, WB_REASON_SYNC); + try_to_writeback_inodes_sb(fs_info->sb, WB_REASON_SYNC); return 0; } -- 2.39.2

2 1

[PATCH OLK-5.10] usb: vhci-hcd: Do not drop references before new references are gained
by Zheng Yejian 26 Aug '24

26 Aug '24

From: Oliver Neukum <oneukum(a)suse.com> stable inclusion from stable-v5.10.224 commit 4dacdb9720aaab10b6be121eae55820174d97174 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAM59O CVE: CVE-2024-43883 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id… -------------------------------- commit afdcfd3d6fcdeca2735ca8d994c5f2d24a368f0a upstream. At a few places the driver carries stale pointers to references that can still be used. Make sure that does not happen. This strictly speaking closes ZDI-CAN-22273, though there may be similar races in the driver. Signed-off-by: Oliver Neukum <oneukum(a)suse.com> Cc: stable <stable(a)kernel.org> Acked-by: Shuah Khan <skhan(a)linuxfoundation.org> Link: https://lore.kernel.org/r/20240709113851.14691-1-oneukum@suse.com Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> Signed-off-by: Zheng Yejian <zhengyejian1(a)huawei.com> --- drivers/usb/usbip/vhci_hcd.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/drivers/usb/usbip/vhci_hcd.c b/drivers/usb/usbip/vhci_hcd.c index b07b2925ff78..affcb928771d 100644 --- a/drivers/usb/usbip/vhci_hcd.c +++ b/drivers/usb/usbip/vhci_hcd.c @@ -745,6 +745,7 @@ static int vhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb, gfp_t mem_flag * */ if (usb_pipedevice(urb->pipe) == 0) { + struct usb_device *old; __u8 type = usb_pipetype(urb->pipe); struct usb_ctrlrequest *ctrlreq = (struct usb_ctrlrequest *) urb->setup_packet; @@ -755,14 +756,15 @@ static int vhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb, gfp_t mem_flag goto no_need_xmit; } + old = vdev->udev; switch (ctrlreq->bRequest) { case USB_REQ_SET_ADDRESS: /* set_address may come when a device is reset */ dev_info(dev, "SetAddress Request (%d) to port %d\n", ctrlreq->wValue, vdev->rhport); - usb_put_dev(vdev->udev); vdev->udev = usb_get_dev(urb->dev); + usb_put_dev(old); spin_lock(&vdev->ud.lock); vdev->ud.status = VDEV_ST_USED; @@ -781,8 +783,8 @@ static int vhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb, gfp_t mem_flag usbip_dbg_vhci_hc( "Not yet?:Get_Descriptor to device 0 (get max pipe size)\n"); - usb_put_dev(vdev->udev); vdev->udev = usb_get_dev(urb->dev); + usb_put_dev(old); goto out; default: @@ -1095,6 +1097,7 @@ static void vhci_shutdown_connection(struct usbip_device *ud) static void vhci_device_reset(struct usbip_device *ud) { struct vhci_device *vdev = container_of(ud, struct vhci_device, ud); + struct usb_device *old = vdev->udev; unsigned long flags; spin_lock_irqsave(&ud->lock, flags); @@ -1102,8 +1105,8 @@ static void vhci_device_reset(struct usbip_device *ud) vdev->speed = 0; vdev->devid = 0; - usb_put_dev(vdev->udev); vdev->udev = NULL; + usb_put_dev(old); if (ud->tcp_socket) { sockfd_put(ud->tcp_socket); -- 2.25.1

2 1

2024

2023

2022

2021

2020

2019

Kernel August 2024