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[PATCH openEuler-1.0-LTS 1/2] sctp: move the active_key update after sh_keys is added
by Yang Yingliang 16 Aug '21

16 Aug '21

From: Xin Long <lucien.xin(a)gmail.com> stable inclusion from linux-4.19.203 commit f91e7bd934c705f25dc6651e29e9c857d48a51f4 -------------------------------- [ Upstream commit ae954bbc451d267f7d60d7b49db811d5a68ebd7b ] In commit 58acd1009226 ("sctp: update active_key for asoc when old key is being replaced"), sctp_auth_asoc_init_active_key() is called to update the active_key right after the old key is deleted and before the new key is added, and it caused that the active_key could be found with the key_id. In Ying Xu's testing, the BUG_ON in sctp_auth_asoc_init_active_key() was triggered: [ ] kernel BUG at net/sctp/auth.c:416! [ ] RIP: 0010:sctp_auth_asoc_init_active_key.part.8+0xe7/0xf0 [sctp] [ ] Call Trace: [ ] sctp_auth_set_key+0x16d/0x1b0 [sctp] [ ] sctp_setsockopt.part.33+0x1ba9/0x2bd0 [sctp] [ ] __sys_setsockopt+0xd6/0x1d0 [ ] __x64_sys_setsockopt+0x20/0x30 [ ] do_syscall_64+0x5b/0x1a0 So fix it by moving the active_key update after sh_keys is added. Fixes: 58acd1009226 ("sctp: update active_key for asoc when old key is being replaced") Reported-by: Ying Xu <yinxu(a)redhat.com> Signed-off-by: Xin Long <lucien.xin(a)gmail.com> Signed-off-by: David S. Miller <davem(a)davemloft.net> Signed-off-by: Sasha Levin <sashal(a)kernel.org> Signed-off-by: Yang Yingliang <yangyingliang(a)huawei.com> Reviewed-by: Yue Haibing <yuehaibing(a)huawei.com> Signed-off-by: Yang Yingliang <yangyingliang(a)huawei.com> --- net/sctp/auth.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) diff --git a/net/sctp/auth.c b/net/sctp/auth.c index b2ca66c4a21d2..9e0c98df20daf 100644 --- a/net/sctp/auth.c +++ b/net/sctp/auth.c @@ -880,14 +880,18 @@ int sctp_auth_set_key(struct sctp_endpoint *ep, memcpy(key->data, &auth_key->sca_key[0], auth_key->sca_keylength); cur_key->key = key; - if (replace) { - list_del_init(&shkey->key_list); - sctp_auth_shkey_release(shkey); - if (asoc && asoc->active_key_id == auth_key->sca_keynumber) - sctp_auth_asoc_init_active_key(asoc, GFP_KERNEL); + if (!replace) { + list_add(&cur_key->key_list, sh_keys); + return 0; } + + list_del_init(&shkey->key_list); + sctp_auth_shkey_release(shkey); list_add(&cur_key->key_list, sh_keys); + if (asoc && asoc->active_key_id == auth_key->sca_keynumber) + sctp_auth_asoc_init_active_key(asoc, GFP_KERNEL); + return 0; } -- 2.25.1

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[PATCH 0/9] Transplantation of KFENCE
by Xie XiuQi 16 Aug '21

16 Aug '21

Hi shang, Thanks for your patchset. Please subscribe the kernel(a)openeuler.org mailing list first, and then resend this patchset again, or your patchset would be blocked. Others who in the mailing list could not receive the emails. Click this link for subscribe mailing list: https://openeuler.org/zh/community/mailing-list/ --- Xie XiuQi On 2021/8/16 20:27, kernel-owner(a)openeuler.org wrote: > As list administrator, your authorization is requested for the > following mailing list posting: > > List: kernel(a)openeuler.org > From: 1415317271(a)qq.com > Subject: [PATCH 0/9] > > The message is being held because: > > The message is not from a list member > > At your convenience, visit your dashboard to approve or deny the > request. >

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[PATCH openEuler-1.0-LTS] usb: max-3421: Prevent corruption of freed memory
by Yang Yingliang 16 Aug '21

16 Aug '21

From: Mark Tomlinson <mark.tomlinson(a)alliedtelesis.co.nz> stable inclusion from linux-4.19.199 commit 51fc12f4d37622fa0c481604833f98f11b1cac4f CVE: CVE-2021-38204 -------------------------------- commit b5fdf5c6e6bee35837e160c00ac89327bdad031b upstream. The MAX-3421 USB driver remembers the state of the USB toggles for a device/endpoint. To save SPI writes, this was only done when a new device/endpoint was being used. Unfortunately, if the old device was removed, this would cause writes to freed memory. To fix this, a simpler scheme is used. The toggles are read from hardware when a URB is completed, and the toggles are always written to hardware when any URB transaction is started. This will cause a few more SPI transactions, but no causes kernel panics. Fixes: 2d53139f3162 ("Add support for using a MAX3421E chip as a host driver.") Cc: stable <stable(a)vger.kernel.org> Signed-off-by: Mark Tomlinson <mark.tomlinson(a)alliedtelesis.co.nz> Link: https://lore.kernel.org/r/20210625031456.8632-1-mark.tomlinson@alliedtelesi… Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> Signed-off-by: Yang Yingliang <yangyingliang(a)huawei.com> Reviewed-by: Xiu Jianfeng <xiujianfeng(a)huawei.com> Signed-off-by: Yang Yingliang <yangyingliang(a)huawei.com> --- drivers/usb/host/max3421-hcd.c | 44 +++++++++++----------------------- 1 file changed, 14 insertions(+), 30 deletions(-) diff --git a/drivers/usb/host/max3421-hcd.c b/drivers/usb/host/max3421-hcd.c index afa321ab55fcf..4a33a18dc0b31 100644 --- a/drivers/usb/host/max3421-hcd.c +++ b/drivers/usb/host/max3421-hcd.c @@ -153,8 +153,6 @@ struct max3421_hcd { */ struct urb *curr_urb; enum scheduling_pass sched_pass; - struct usb_device *loaded_dev; /* dev that's loaded into the chip */ - int loaded_epnum; /* epnum whose toggles are loaded */ int urb_done; /* > 0 -> no errors, < 0: errno */ size_t curr_len; u8 hien; @@ -492,39 +490,17 @@ max3421_set_speed(struct usb_hcd *hcd, struct usb_device *dev) * Caller must NOT hold HCD spinlock. */ static void -max3421_set_address(struct usb_hcd *hcd, struct usb_device *dev, int epnum, - int force_toggles) +max3421_set_address(struct usb_hcd *hcd, struct usb_device *dev, int epnum) { - struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd); - int old_epnum, same_ep, rcvtog, sndtog; - struct usb_device *old_dev; + int rcvtog, sndtog; u8 hctl; - old_dev = max3421_hcd->loaded_dev; - old_epnum = max3421_hcd->loaded_epnum; - - same_ep = (dev == old_dev && epnum == old_epnum); - if (same_ep && !force_toggles) - return; - - if (old_dev && !same_ep) { - /* save the old end-points toggles: */ - u8 hrsl = spi_rd8(hcd, MAX3421_REG_HRSL); - - rcvtog = (hrsl >> MAX3421_HRSL_RCVTOGRD_BIT) & 1; - sndtog = (hrsl >> MAX3421_HRSL_SNDTOGRD_BIT) & 1; - - /* no locking: HCD (i.e., we) own toggles, don't we? */ - usb_settoggle(old_dev, old_epnum, 0, rcvtog); - usb_settoggle(old_dev, old_epnum, 1, sndtog); - } /* setup new endpoint's toggle bits: */ rcvtog = usb_gettoggle(dev, epnum, 0); sndtog = usb_gettoggle(dev, epnum, 1); hctl = (BIT(rcvtog + MAX3421_HCTL_RCVTOG0_BIT) | BIT(sndtog + MAX3421_HCTL_SNDTOG0_BIT)); - max3421_hcd->loaded_epnum = epnum; spi_wr8(hcd, MAX3421_REG_HCTL, hctl); /* @@ -532,7 +508,6 @@ max3421_set_address(struct usb_hcd *hcd, struct usb_device *dev, int epnum, * address-assignment so it's best to just always load the * address whenever the end-point changed/was forced. */ - max3421_hcd->loaded_dev = dev; spi_wr8(hcd, MAX3421_REG_PERADDR, dev->devnum); } @@ -667,7 +642,7 @@ max3421_select_and_start_urb(struct usb_hcd *hcd) struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd); struct urb *urb, *curr_urb = NULL; struct max3421_ep *max3421_ep; - int epnum, force_toggles = 0; + int epnum; struct usb_host_endpoint *ep; struct list_head *pos; unsigned long flags; @@ -777,7 +752,6 @@ max3421_select_and_start_urb(struct usb_hcd *hcd) usb_settoggle(urb->dev, epnum, 0, 1); usb_settoggle(urb->dev, epnum, 1, 1); max3421_ep->pkt_state = PKT_STATE_SETUP; - force_toggles = 1; } else max3421_ep->pkt_state = PKT_STATE_TRANSFER; } @@ -785,7 +759,7 @@ max3421_select_and_start_urb(struct usb_hcd *hcd) spin_unlock_irqrestore(&max3421_hcd->lock, flags); max3421_ep->last_active = max3421_hcd->frame_number; - max3421_set_address(hcd, urb->dev, epnum, force_toggles); + max3421_set_address(hcd, urb->dev, epnum); max3421_set_speed(hcd, urb->dev); max3421_next_transfer(hcd, 0); return 1; @@ -1380,6 +1354,16 @@ max3421_urb_done(struct usb_hcd *hcd) status = 0; urb = max3421_hcd->curr_urb; if (urb) { + /* save the old end-points toggles: */ + u8 hrsl = spi_rd8(hcd, MAX3421_REG_HRSL); + int rcvtog = (hrsl >> MAX3421_HRSL_RCVTOGRD_BIT) & 1; + int sndtog = (hrsl >> MAX3421_HRSL_SNDTOGRD_BIT) & 1; + int epnum = usb_endpoint_num(&urb->ep->desc); + + /* no locking: HCD (i.e., we) own toggles, don't we? */ + usb_settoggle(urb->dev, epnum, 0, rcvtog); + usb_settoggle(urb->dev, epnum, 1, sndtog); + max3421_hcd->curr_urb = NULL; spin_lock_irqsave(&max3421_hcd->lock, flags); usb_hcd_unlink_urb_from_ep(hcd, urb); -- 2.25.1

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[PATCH kernel-4.19] net: ll_temac: Fix bug causing buffer descriptor overrun
by Yang Yingliang 16 Aug '21

16 Aug '21

From: Esben Haabendal <esben(a)geanix.com> mainline inclusion from mainline-v5.2-rc1 commit 2c9938e738a273ba315679781a9990c7d3b1831b category: bugfix bugzilla: NA CVE: CVE-2021-38207 --------------------------- As we are actually using a BD for both the skb and each frag contained in it, the oldest TX BD would be overwritten when there was exactly one BD less than needed. Signed-off-by: Esben Haabendal <esben(a)geanix.com> Signed-off-by: David S. Miller <davem(a)davemloft.net> Signed-off-by: Yang Yingliang <yangyingliang(a)huawei.com> Reviewed-by: Yue Haibing <yuehaibing(a)huawei.com> Reviewed-by: Xiu Jianfeng <xiujianfeng(a)huawei.com> Signed-off-by: Yang Yingliang <yangyingliang(a)huawei.com> --- drivers/net/ethernet/xilinx/ll_temac_main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/ethernet/xilinx/ll_temac_main.c b/drivers/net/ethernet/xilinx/ll_temac_main.c index 939de185bc6b8..2caff1a5585e7 100644 --- a/drivers/net/ethernet/xilinx/ll_temac_main.c +++ b/drivers/net/ethernet/xilinx/ll_temac_main.c @@ -689,7 +689,7 @@ temac_start_xmit(struct sk_buff *skb, struct net_device *ndev) start_p = lp->tx_bd_p + sizeof(*lp->tx_bd_v) * lp->tx_bd_tail; cur_p = &lp->tx_bd_v[lp->tx_bd_tail]; - if (temac_check_tx_bd_space(lp, num_frag)) { + if (temac_check_tx_bd_space(lp, num_frag + 1)) { if (!netif_queue_stopped(ndev)) netif_stop_queue(ndev); return NETDEV_TX_BUSY; -- 2.25.1

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[PATCH kernel-4.19] tcp_comp: Avoiding the null pointer problem of ctx in comp_stream_read
by Yang Yingliang 16 Aug '21

16 Aug '21

From: Wang Yufen <wangyufen(a)huawei.com> hulk inclusion category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I45UYC?from=project-issue CVE: NA ------------------------------------------------- In comp_stream_read ctx might be null, add null check to avoid oops. And delete unnecessary tcp_comp_err_abort. Signed-off-by: Wang Yufen <wangyufen(a)huawei.com> Reviewed-by: Yue Haibing <yuehaibing(a)huawei.com> Reviewed-by: Wei Yongjun <weiyongjun1(a)huawei.com> Signed-off-by: Yang Yingliang <yangyingliang(a)huawei.com> --- net/ipv4/tcp_comp.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/net/ipv4/tcp_comp.c b/net/ipv4/tcp_comp.c index e7f6094b5aeec..f6ebe52f3f7f7 100644 --- a/net/ipv4/tcp_comp.c +++ b/net/ipv4/tcp_comp.c @@ -723,8 +723,6 @@ static int tcp_comp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, if (!ctx->rx.decompressed) { err = tcp_comp_decompress(sk, skb); if (err < 0) { - if (err != -ENOSPC) - tcp_comp_err_abort(sk, EBADMSG); goto recv_end; } ctx->rx.decompressed = true; @@ -758,6 +756,9 @@ bool comp_stream_read(const struct sock *sk) { struct tcp_comp_context *ctx = comp_get_ctx(sk); + if (!ctx) + return false; + if (ctx->rx.pkt) return true; -- 2.25.1

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[PATCH kernel-4.19 1/2] ext4: fix potential uninitialized access to retval in kmmpd
by Yang Yingliang 16 Aug '21

16 Aug '21

From: Ye Bin <yebin10(a)huawei.com> mainline inclusion from mainline-5.14-rc5 commit b66541422824cf6cf20e9a35112e9cb5d82cdf62 category: bugfix bugzilla: 175849 CVE: NA ------------------------------------------------- if (!ext4_has_feature_mmp(sb)) then retval can be unitialized before we jump to the wait_to_exit label. Fixes: 61bb4a1c417e ("ext4: fix possible UAF when remounting r/o a mmp-protected file system") Signed-off-by: Ye Bin <yebin10(a)huawei.com> Link: https://lore.kernel.org/r/20210713022728.2533770-1-yebin10@huawei.com Signed-off-by: Theodore Ts'o <tytso(a)mit.edu> Signed-off-by: Baokun Li <libaokun1(a)huawei.com> Reviewed-by: Zhang Yi <yi.zhang(a)huawei.com> Signed-off-by: Yang Yingliang <yangyingliang(a)huawei.com> --- fs/ext4/mmp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/ext4/mmp.c b/fs/ext4/mmp.c index 5af24925ffa83..0e9569dc02da2 100644 --- a/fs/ext4/mmp.c +++ b/fs/ext4/mmp.c @@ -138,7 +138,7 @@ static int kmmpd(void *data) unsigned mmp_check_interval; unsigned long last_update_time; unsigned long diff; - int retval; + int retval = 0; mmp_block = le64_to_cpu(es->s_mmp_block); mmp = (struct mmp_struct *)(bh->b_data); -- 2.25.1

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[PATCH openEuler-1.0-LTS 1/2] blk-mq: fix hang caused by freeze/unfreeze sequence
by Yang Yingliang 16 Aug '21

16 Aug '21

From: Bob Liu <bob.liu(a)oracle.com> mainline inclusion from mainline-v5.2-rc2 commit 7996a8b5511a72465b0b286763c2d8f412b8874a category: bugfix bugzilla: 173119 CVE: NA ----------------------------------------------- The following is a description of a hang in blk_mq_freeze_queue_wait(). The hang happens on attempt to freeze a queue while another task does queue unfreeze. The root cause is an incorrect sequence of percpu_ref_resurrect() and percpu_ref_kill() and as a result those two can be swapped: CPU#0 CPU#1 ---------------- ----------------- q1 = blk_mq_init_queue(shared_tags) q2 = blk_mq_init_queue(shared_tags): blk_mq_add_queue_tag_set(shared_tags): blk_mq_update_tag_set_depth(shared_tags): list_for_each_entry() blk_mq_freeze_queue(q1) > percpu_ref_kill() > blk_mq_freeze_queue_wait() blk_cleanup_queue(q1) blk_mq_freeze_queue(q1) > percpu_ref_kill() ^^^^^^ freeze_depth can't guarantee the order blk_mq_unfreeze_queue() > percpu_ref_resurrect() > blk_mq_freeze_queue_wait() ^^^^^^ Hang here!!!! This wrong sequence raises kernel warning: percpu_ref_kill_and_confirm called more than once on blk_queue_usage_counter_release! WARNING: CPU: 0 PID: 11854 at lib/percpu-refcount.c:336 percpu_ref_kill_and_confirm+0x99/0xb0 But the most unpleasant effect is a hang of a blk_mq_freeze_queue_wait(), which waits for a zero of a q_usage_counter, which never happens because percpu-ref was reinited (instead of being killed) and stays in PERCPU state forever. How to reproduce: - "insmod null_blk.ko shared_tags=1 nr_devices=0 queue_mode=2" - cpu0: python Script.py 0; taskset the corresponding process running on cpu0 - cpu1: python Script.py 1; taskset the corresponding process running on cpu1 Script.py: ------ #!/usr/bin/python3 import os import sys while True: on = "echo 1 > /sys/kernel/config/nullb/%s/power" % sys.argv[1] off = "echo 0 > /sys/kernel/config/nullb/%s/power" % sys.argv[1] os.system(on) os.system(off) ------ This bug was first reported and fixed by Roman, previous discussion: [1] Message id: 1443287365-4244-7-git-send-email-akinobu.mita(a)gmail.com [2] Message id: 1443563240-29306-6-git-send-email-tj(a)kernel.org [3] https://patchwork.kernel.org/patch/9268199/ Reviewed-by: Hannes Reinecke <hare(a)suse.com> Reviewed-by: Ming Lei <ming.lei(a)redhat.com> Reviewed-by: Bart Van Assche <bvanassche(a)acm.org> Reviewed-by: Christoph Hellwig <hch(a)lst.de> Signed-off-by: Roman Pen <roman.penyaev(a)profitbricks.com> Signed-off-by: Bob Liu <bob.liu(a)oracle.com> Signed-off-by: Jens Axboe <axboe(a)kernel.dk> Signed-off-by: Yu Kuai <yukuai3(a)huawei.com> Reviewed-by: Hou Tao <houtao1(a)huawei.com> Signed-off-by: Yang Yingliang <yangyingliang(a)huawei.com> --- block/blk-core.c | 3 ++- block/blk-mq.c | 19 ++++++++++--------- include/linux/blkdev.h | 7 ++++++- 3 files changed, 18 insertions(+), 11 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index 2f66d43c476f3..b67cb175b9737 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -955,7 +955,7 @@ int blk_queue_enter(struct request_queue *q, blk_mq_req_flags_t flags) smp_rmb(); wait_event(q->mq_freeze_wq, - (atomic_read(&q->mq_freeze_depth) == 0 && + (!q->mq_freeze_depth && (pm || !blk_queue_pm_only(q))) || blk_queue_dying(q)); if (blk_queue_dying(q)) @@ -1071,6 +1071,7 @@ struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id, queue_flag_set_unlocked(QUEUE_FLAG_BYPASS, q); init_waitqueue_head(&q->mq_freeze_wq); + mutex_init(&q->mq_freeze_lock); /* * Init percpu_ref in atomic mode so that it's faster to shutdown. diff --git a/block/blk-mq.c b/block/blk-mq.c index 607ee5dafa2e9..0de720aa544fa 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -136,13 +136,14 @@ void blk_mq_in_flight_rw(struct request_queue *q, struct hd_struct *part, void blk_freeze_queue_start(struct request_queue *q) { - int freeze_depth; - - freeze_depth = atomic_inc_return(&q->mq_freeze_depth); - if (freeze_depth == 1) { + mutex_lock(&q->mq_freeze_lock); + if (++q->mq_freeze_depth == 1) { percpu_ref_kill(&q->q_usage_counter); + mutex_unlock(&q->mq_freeze_lock); if (q->mq_ops) blk_mq_run_hw_queues(q, false); + } else { + mutex_unlock(&q->mq_freeze_lock); } } EXPORT_SYMBOL_GPL(blk_freeze_queue_start); @@ -193,14 +194,14 @@ EXPORT_SYMBOL_GPL(blk_mq_freeze_queue); void blk_mq_unfreeze_queue(struct request_queue *q) { - int freeze_depth; - - freeze_depth = atomic_dec_return(&q->mq_freeze_depth); - WARN_ON_ONCE(freeze_depth < 0); - if (!freeze_depth) { + mutex_lock(&q->mq_freeze_lock); + q->mq_freeze_depth--; + WARN_ON_ONCE(q->mq_freeze_depth < 0); + if (!q->mq_freeze_depth) { percpu_ref_reinit(&q->q_usage_counter); wake_up_all(&q->mq_freeze_wq); } + mutex_unlock(&q->mq_freeze_lock); } EXPORT_SYMBOL_GPL(blk_mq_unfreeze_queue); diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index ad2b10c4a0797..bb0ac8cbbb4c0 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -655,7 +655,7 @@ struct request_queue { spinlock_t unused_hctx_lock; int bypass_depth; - atomic_t mq_freeze_depth; + int mq_freeze_depth; #if defined(CONFIG_BLK_DEV_BSG) bsg_job_fn *bsg_job_fn; @@ -668,6 +668,11 @@ struct request_queue { #endif struct rcu_head rcu_head; wait_queue_head_t mq_freeze_wq; + /* + * Protect concurrent access to q_usage_counter by + * percpu_ref_kill() and percpu_ref_reinit(). + */ + struct mutex mq_freeze_lock; struct percpu_ref q_usage_counter; struct list_head all_q_node; -- 2.25.1

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[PATCH kernel-4.19] blk-mq: fix hang caused by freeze/unfreeze sequence
by Yang Yingliang 16 Aug '21

16 Aug '21

From: Bob Liu <bob.liu(a)oracle.com> mainline inclusion from mainline-v5.2-rc2 commit 7996a8b5511a72465b0b286763c2d8f412b8874a category: bugfix bugzilla: 173119 CVE: NA ----------------------------------------------- The following is a description of a hang in blk_mq_freeze_queue_wait(). The hang happens on attempt to freeze a queue while another task does queue unfreeze. The root cause is an incorrect sequence of percpu_ref_resurrect() and percpu_ref_kill() and as a result those two can be swapped: CPU#0 CPU#1 ---------------- ----------------- q1 = blk_mq_init_queue(shared_tags) q2 = blk_mq_init_queue(shared_tags): blk_mq_add_queue_tag_set(shared_tags): blk_mq_update_tag_set_depth(shared_tags): list_for_each_entry() blk_mq_freeze_queue(q1) > percpu_ref_kill() > blk_mq_freeze_queue_wait() blk_cleanup_queue(q1) blk_mq_freeze_queue(q1) > percpu_ref_kill() ^^^^^^ freeze_depth can't guarantee the order blk_mq_unfreeze_queue() > percpu_ref_resurrect() > blk_mq_freeze_queue_wait() ^^^^^^ Hang here!!!! This wrong sequence raises kernel warning: percpu_ref_kill_and_confirm called more than once on blk_queue_usage_counter_release! WARNING: CPU: 0 PID: 11854 at lib/percpu-refcount.c:336 percpu_ref_kill_and_confirm+0x99/0xb0 But the most unpleasant effect is a hang of a blk_mq_freeze_queue_wait(), which waits for a zero of a q_usage_counter, which never happens because percpu-ref was reinited (instead of being killed) and stays in PERCPU state forever. How to reproduce: - "insmod null_blk.ko shared_tags=1 nr_devices=0 queue_mode=2" - cpu0: python Script.py 0; taskset the corresponding process running on cpu0 - cpu1: python Script.py 1; taskset the corresponding process running on cpu1 Script.py: ------ #!/usr/bin/python3 import os import sys while True: on = "echo 1 > /sys/kernel/config/nullb/%s/power" % sys.argv[1] off = "echo 0 > /sys/kernel/config/nullb/%s/power" % sys.argv[1] os.system(on) os.system(off) ------ This bug was first reported and fixed by Roman, previous discussion: [1] Message id: 1443287365-4244-7-git-send-email-akinobu.mita(a)gmail.com [2] Message id: 1443563240-29306-6-git-send-email-tj(a)kernel.org [3] https://patchwork.kernel.org/patch/9268199/ Reviewed-by: Hannes Reinecke <hare(a)suse.com> Reviewed-by: Ming Lei <ming.lei(a)redhat.com> Reviewed-by: Bart Van Assche <bvanassche(a)acm.org> Reviewed-by: Christoph Hellwig <hch(a)lst.de> Signed-off-by: Roman Pen <roman.penyaev(a)profitbricks.com> Signed-off-by: Bob Liu <bob.liu(a)oracle.com> Signed-off-by: Jens Axboe <axboe(a)kernel.dk> Signed-off-by: Yu Kuai <yukuai3(a)huawei.com> Reviewed-by: Hou Tao <houtao1(a)huawei.com> Signed-off-by: Yang Yingliang <yangyingliang(a)huawei.com> --- block/blk-core.c | 3 ++- block/blk-mq.c | 19 ++++++++++--------- include/linux/blkdev.h | 7 ++++++- 3 files changed, 18 insertions(+), 11 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index 4b63336465306..34456f2bf45c3 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -955,7 +955,7 @@ int blk_queue_enter(struct request_queue *q, blk_mq_req_flags_t flags) smp_rmb(); wait_event(q->mq_freeze_wq, - (atomic_read(&q->mq_freeze_depth) == 0 && + (!q->mq_freeze_depth && (pm || !blk_queue_pm_only(q))) || blk_queue_dying(q)); if (blk_queue_dying(q)) @@ -1072,6 +1072,7 @@ struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id, queue_flag_set_unlocked(QUEUE_FLAG_BYPASS, q); init_waitqueue_head(&q->mq_freeze_wq); + mutex_init(&q->mq_freeze_lock); /* * Init percpu_ref in atomic mode so that it's faster to shutdown. diff --git a/block/blk-mq.c b/block/blk-mq.c index f684053ecd51f..dc96754abc2cd 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -136,13 +136,14 @@ void blk_mq_in_flight_rw(struct request_queue *q, struct hd_struct *part, void blk_freeze_queue_start(struct request_queue *q) { - int freeze_depth; - - freeze_depth = atomic_inc_return(&q->mq_freeze_depth); - if (freeze_depth == 1) { + mutex_lock(&q->mq_freeze_lock); + if (++q->mq_freeze_depth == 1) { percpu_ref_kill(&q->q_usage_counter); + mutex_unlock(&q->mq_freeze_lock); if (q->mq_ops) blk_mq_run_hw_queues(q, false); + } else { + mutex_unlock(&q->mq_freeze_lock); } } EXPORT_SYMBOL_GPL(blk_freeze_queue_start); @@ -193,14 +194,14 @@ EXPORT_SYMBOL_GPL(blk_mq_freeze_queue); void blk_mq_unfreeze_queue(struct request_queue *q) { - int freeze_depth; - - freeze_depth = atomic_dec_return(&q->mq_freeze_depth); - WARN_ON_ONCE(freeze_depth < 0); - if (!freeze_depth) { + mutex_lock(&q->mq_freeze_lock); + q->mq_freeze_depth--; + WARN_ON_ONCE(q->mq_freeze_depth < 0); + if (!q->mq_freeze_depth) { percpu_ref_reinit(&q->q_usage_counter); wake_up_all(&q->mq_freeze_wq); } + mutex_unlock(&q->mq_freeze_lock); } EXPORT_SYMBOL_GPL(blk_mq_unfreeze_queue); diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 1ce80e23eeab1..376f5dee46fce 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -660,7 +660,7 @@ struct request_queue { spinlock_t unused_hctx_lock; int bypass_depth; - atomic_t mq_freeze_depth; + int mq_freeze_depth; #if defined(CONFIG_BLK_DEV_BSG) bsg_job_fn *bsg_job_fn; @@ -673,6 +673,11 @@ struct request_queue { #endif struct rcu_head rcu_head; wait_queue_head_t mq_freeze_wq; + /* + * Protect concurrent access to q_usage_counter by + * percpu_ref_kill() and percpu_ref_reinit(). + */ + struct mutex mq_freeze_lock; struct percpu_ref q_usage_counter; struct list_head all_q_node; -- 2.25.1

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[PATCH kernel-4.19 00/14] backport linux-4.19.202
by Yang Yingliang 16 Aug '21

16 Aug '21

Axel Lin (1): regulator: rt5033: Fix n_voltages settings for BUCK and LDO Daniel Jordan (2): padata: validate cpumask without removed CPU during offline padata: add separate cpuhp node for CPUHP_PADATA_DEAD Goldwyn Rodrigues (1): btrfs: mark compressed range uptodate only if all bio succeed Greg Kroah-Hartman (3): Revert "Bluetooth: Shutdown controller after workqueues are flushed or cancelled" Revert "watchdog: iTCO_wdt: Account for rebooting on second timeout" Linux 4.19.202 Guenter Roeck (1): spi: mediatek: Fix fifo transfer Jani Nikula (1): drm/i915: Ensure intel_engine_init_execlist() builds with Clang Jia He (1): qed: fix possible unpaired spin_{un}lock_bh in _qed_mcp_cmd_and_union() Kyle Russell (1): ASoC: tlv320aic31xx: fix reversed bclk/wclk master bits Pravin B Shelar (1): net: Fix zero-copy head len calculation. Sudeep Holla (1): firmware: arm_scmi: Ensure drivers provide a probe function Takashi Iwai (1): r8152: Fix potential PM refcount imbalance Makefile | 2 +- drivers/firmware/arm_scmi/bus.c | 3 +++ drivers/gpu/drm/i915/intel_engine_cs.c | 2 +- drivers/net/ethernet/qlogic/qed/qed_mcp.c | 23 ++++++++++++++----- drivers/net/usb/r8152.c | 3 ++- drivers/spi/spi-mt65xx.c | 19 ++++----------- drivers/watchdog/iTCO_wdt.c | 12 +++------- fs/btrfs/compression.c | 3 +-- include/linux/cpuhotplug.h | 1 + include/linux/mfd/rt5033-private.h | 4 ++-- include/linux/padata.h | 6 +++-- kernel/padata.c | 28 ++++++++++++++++------- net/bluetooth/hci_core.c | 16 ++++++------- net/core/skbuff.c | 5 +++- sound/soc/codecs/tlv320aic31xx.h | 4 ++-- 15 files changed, 74 insertions(+), 57 deletions(-) -- 2.25.1

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[PATCH openEuler-1.0-LTS v2 0/5] Introduce default passthrough mode for some SoCs
by Hanjun Guo 16 Aug '21

16 Aug '21

Extended the SMMU_BYPASS_DEV to support SMMU default bypass for some CPU SoCs which the SMMU is not functional well in address translation mode. This patch set based on openEuler kernel LTS 1.0. v2: Adding another patch which other four patches based on. Thanks! Cc: Guo Hui <guohui(a)uniontech.com> Cc: Cheng Jian <cj.chengjian(a)huawei.com> Cc: Zhen Lei <thunder.leizhen(a)huawei.com> Cc: Xiuqi Xie <xiexiuqi(a)huawei.com> Guo Hui (1): arm64: Add MIDR encoding for PHYTIUM CPUs Hanjun Guo (3): arm64: phytium: using MIDR_PHYTIUM_FT2000PLUS instead of ARM_CPU_IMP_PHYTIUM iommu: dev_bypass: cleanup dev bypass code iommu: smmuv2: Using the SMMU_BYPASS_DEV to bypass SMMU for some SoCs Weilong Chen (1): arm64: Add MIDR encoding for HiSilicon Taishan CPUs arch/arm64/include/asm/cputype.h | 7 +++++++ arch/arm64/kernel/topology.c | 6 +++--- drivers/iommu/Kconfig | 14 +++++++++++--- drivers/iommu/arm-smmu-v3.c | 2 +- drivers/iommu/arm-smmu.c | 28 ++++++++++++++++++++++++++++ drivers/iommu/iommu.c | 13 ++++--------- drivers/usb/host/xhci-pci.c | 4 +++- 7 files changed, 57 insertions(+), 17 deletions(-) -- 1.7.12.4

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