July 2023 - Kernel - mailweb.openeuler.org

[PATCH OLK-5.10] media: dvb-core: Fix use-after-free due on race condition at dvb_net
by Cai Xinchen 18 Jul '23

18 Jul '23

From: Hyunwoo Kim <imv4bel(a)gmail.com> mainline inclusion from mainline-v6.4-rc3 commit 4172385b0c9ac366dcab78eda48c26814b87ed1a category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I635JD CVE: CVE-2022-45886 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit?i… ---------------------------------------- A race condition may occur between the .disconnect function, which is called when the device is disconnected, and the dvb_device_open() function, which is called when the device node is open()ed. This results in several types of UAFs. The root cause of this is that you use the dvb_device_open() function, which does not implement a conditional statement that checks 'dvbnet->exit'. So, add 'remove_mutex` to protect 'dvbnet->exit' and use locked_dvb_net_open() function to check 'dvbnet->exit'. [mchehab: fix a checkpatch warning] Link: https://lore.kernel.org/linux-media/20221117045925.14297-3-imv4bel@gmail.com Signed-off-by: Hyunwoo Kim <imv4bel(a)gmail.com> Signed-off-by: Mauro Carvalho Chehab <mchehab(a)kernel.org> Signed-off-by: Cai Xinchen <caixinchen1(a)huawei.com> --- drivers/media/dvb-core/dvb_net.c | 38 +++++++++++++++++++++++++++++--- include/media/dvb_net.h | 4 ++++ 2 files changed, 39 insertions(+), 3 deletions(-) diff --git a/drivers/media/dvb-core/dvb_net.c b/drivers/media/dvb-core/dvb_net.c index 10f78109bb3f..d8bdca2bf566 100644 --- a/drivers/media/dvb-core/dvb_net.c +++ b/drivers/media/dvb-core/dvb_net.c @@ -1562,15 +1562,43 @@ static long dvb_net_ioctl(struct file *file, return dvb_usercopy(file, cmd, arg, dvb_net_do_ioctl); } +static int locked_dvb_net_open(struct inode *inode, struct file *file) +{ + struct dvb_device *dvbdev = file->private_data; + struct dvb_net *dvbnet = dvbdev->priv; + int ret; + + if (mutex_lock_interruptible(&dvbnet->remove_mutex)) + return -ERESTARTSYS; + + if (dvbnet->exit) { + mutex_unlock(&dvbnet->remove_mutex); + return -ENODEV; + } + + ret = dvb_generic_open(inode, file); + + mutex_unlock(&dvbnet->remove_mutex); + + return ret; +} + static int dvb_net_close(struct inode *inode, struct file *file) { struct dvb_device *dvbdev = file->private_data; struct dvb_net *dvbnet = dvbdev->priv; + mutex_lock(&dvbnet->remove_mutex); + dvb_generic_release(inode, file); - if(dvbdev->users == 1 && dvbnet->exit == 1) + if (dvbdev->users == 1 && dvbnet->exit == 1) { + mutex_unlock(&dvbnet->remove_mutex); wake_up(&dvbdev->wait_queue); + } else { + mutex_unlock(&dvbnet->remove_mutex); + } + return 0; } @@ -1578,7 +1606,7 @@ static int dvb_net_close(struct inode *inode, struct file *file) static const struct file_operations dvb_net_fops = { .owner = THIS_MODULE, .unlocked_ioctl = dvb_net_ioctl, - .open = dvb_generic_open, + .open = locked_dvb_net_open, .release = dvb_net_close, .llseek = noop_llseek, }; @@ -1597,10 +1625,13 @@ void dvb_net_release (struct dvb_net *dvbnet) { int i; + mutex_lock(&dvbnet->remove_mutex); dvbnet->exit = 1; + mutex_unlock(&dvbnet->remove_mutex); + if (dvbnet->dvbdev->users < 1) wait_event(dvbnet->dvbdev->wait_queue, - dvbnet->dvbdev->users==1); + dvbnet->dvbdev->users == 1); dvb_unregister_device(dvbnet->dvbdev); @@ -1619,6 +1650,7 @@ int dvb_net_init (struct dvb_adapter *adap, struct dvb_net *dvbnet, int i; mutex_init(&dvbnet->ioctl_mutex); + mutex_init(&dvbnet->remove_mutex); dvbnet->demux = dmx; for (i=0; i<DVB_NET_DEVICES_MAX; i++) diff --git a/include/media/dvb_net.h b/include/media/dvb_net.h index 5e31d37f25fa..cc01dffcc9f3 100644 --- a/include/media/dvb_net.h +++ b/include/media/dvb_net.h @@ -41,6 +41,9 @@ * @exit: flag to indicate when the device is being removed. * @demux: pointer to &struct dmx_demux. * @ioctl_mutex: protect access to this struct. + * @remove_mutex: mutex that avoids a race condition between a callback + * called when the hardware is disconnected and the + * file_operations of dvb_net. * * Currently, the core supports up to %DVB_NET_DEVICES_MAX (10) network * devices. @@ -53,6 +56,7 @@ struct dvb_net { unsigned int exit:1; struct dmx_demux *demux; struct mutex ioctl_mutex; + struct mutex remove_mutex; }; /** -- 2.17.1

2 1

[PATCH openEuler-1.0-LTS 0/2] Tracing fixes
by Zheng Yejian 18 Jul '23

18 Jul '23

Tracing fixes: - Fix a deadloop in reading trace_pipe that was caused by a mismatch between ring_buffer_empty() returning false which then asked to read the data, but the read code uses rb_num_of_entries() that returned zero, and causing an infinite "retry". - Fix a warning caused by not using all pages allocated to store ftrace functions, where this can happen if the linker inserts a bunch of "NULL" entries, causing the accounting of how many pages needed to be off. Zheng Yejian (2): ring-buffer: Fix deadloop issue on reading trace_pipe ftrace: Fix possible warning on checking all pages used in ftrace_process_locs() kernel/trace/ftrace.c | 41 +++++++++++++++++++++++++++----------- kernel/trace/ring_buffer.c | 24 +++++++++++++--------- 2 files changed, 44 insertions(+), 21 deletions(-) -- 2.25.1

2 3

[PATCH OLK-5.10] media: dvb-core: Fix use-after-free due on race condition at dvb_net
by Cai Xinchen 18 Jul '23

18 Jul '23

From: Hyunwoo Kim <imv4bel(a)gmail.com> mainline inclusion from mainline-v6.4-rc3 commit 4172385b0c9ac366dcab78eda48c26814b87ed1a category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I635JD CVE: CVE-2022-45886 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit?i… ---------------------------------------- A race condition may occur between the .disconnect function, which is called when the device is disconnected, and the dvb_device_open() function, which is called when the device node is open()ed. This results in several types of UAFs. The root cause of this is that you use the dvb_device_open() function, which does not implement a conditional statement that checks 'dvbnet->exit'. So, add 'remove_mutex` to protect 'dvbnet->exit' and use locked_dvb_net_open() function to check 'dvbnet->exit'. [mchehab: fix a checkpatch warning] Link: https://lore.kernel.org/linux-media/20221117045925.14297-3-imv4bel@gmail.com Signed-off-by: Hyunwoo Kim <imv4bel(a)gmail.com> Signed-off-by: Mauro Carvalho Chehab <mchehab(a)kernel.org> Signed-off-by: Cai Xinchen <caixinchen1(a)huawei.com> --- drivers/media/dvb-core/dvb_net.c | 38 +++++++++++++++++++++++++++++--- include/media/dvb_net.h | 4 ++++ 2 files changed, 39 insertions(+), 3 deletions(-) diff --git a/drivers/media/dvb-core/dvb_net.c b/drivers/media/dvb-core/dvb_net.c index 10f78109bb3f..d8bdca2bf566 100644 --- a/drivers/media/dvb-core/dvb_net.c +++ b/drivers/media/dvb-core/dvb_net.c @@ -1562,15 +1562,43 @@ static long dvb_net_ioctl(struct file *file, return dvb_usercopy(file, cmd, arg, dvb_net_do_ioctl); } +static int locked_dvb_net_open(struct inode *inode, struct file *file) +{ + struct dvb_device *dvbdev = file->private_data; + struct dvb_net *dvbnet = dvbdev->priv; + int ret; + + if (mutex_lock_interruptible(&dvbnet->remove_mutex)) + return -ERESTARTSYS; + + if (dvbnet->exit) { + mutex_unlock(&dvbnet->remove_mutex); + return -ENODEV; + } + + ret = dvb_generic_open(inode, file); + + mutex_unlock(&dvbnet->remove_mutex); + + return ret; +} + static int dvb_net_close(struct inode *inode, struct file *file) { struct dvb_device *dvbdev = file->private_data; struct dvb_net *dvbnet = dvbdev->priv; + mutex_lock(&dvbnet->remove_mutex); + dvb_generic_release(inode, file); - if(dvbdev->users == 1 && dvbnet->exit == 1) + if (dvbdev->users == 1 && dvbnet->exit == 1) { + mutex_unlock(&dvbnet->remove_mutex); wake_up(&dvbdev->wait_queue); + } else { + mutex_unlock(&dvbnet->remove_mutex); + } + return 0; } @@ -1578,7 +1606,7 @@ static int dvb_net_close(struct inode *inode, struct file *file) static const struct file_operations dvb_net_fops = { .owner = THIS_MODULE, .unlocked_ioctl = dvb_net_ioctl, - .open = dvb_generic_open, + .open = locked_dvb_net_open, .release = dvb_net_close, .llseek = noop_llseek, }; @@ -1597,10 +1625,13 @@ void dvb_net_release (struct dvb_net *dvbnet) { int i; + mutex_lock(&dvbnet->remove_mutex); dvbnet->exit = 1; + mutex_unlock(&dvbnet->remove_mutex); + if (dvbnet->dvbdev->users < 1) wait_event(dvbnet->dvbdev->wait_queue, - dvbnet->dvbdev->users==1); + dvbnet->dvbdev->users == 1); dvb_unregister_device(dvbnet->dvbdev); @@ -1619,6 +1650,7 @@ int dvb_net_init (struct dvb_adapter *adap, struct dvb_net *dvbnet, int i; mutex_init(&dvbnet->ioctl_mutex); + mutex_init(&dvbnet->remove_mutex); dvbnet->demux = dmx; for (i=0; i<DVB_NET_DEVICES_MAX; i++) diff --git a/include/media/dvb_net.h b/include/media/dvb_net.h index 5e31d37f25fa..cc01dffcc9f3 100644 --- a/include/media/dvb_net.h +++ b/include/media/dvb_net.h @@ -41,6 +41,9 @@ * @exit: flag to indicate when the device is being removed. * @demux: pointer to &struct dmx_demux. * @ioctl_mutex: protect access to this struct. + * @remove_mutex: mutex that avoids a race condition between a callback + * called when the hardware is disconnected and the + * file_operations of dvb_net. * * Currently, the core supports up to %DVB_NET_DEVICES_MAX (10) network * devices. @@ -53,6 +56,7 @@ struct dvb_net { unsigned int exit:1; struct dmx_demux *demux; struct mutex ioctl_mutex; + struct mutex remove_mutex; }; /** -- 2.17.1

2 1

[PATCH openEuler-23.09] arm64/vmalloc: use module region only for module_alloc() if CONFIG_RANDOMIZE_BASE is set
by Liu Shixin 18 Jul '23

18 Jul '23

hulk inclusion category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I6DAD6 -------------------------------- After I add a 10GB pmem device, I got the following error message when insert module: insmod: vmalloc error: size 16384, vm_struct allocation failed, mode:0xcc0(GFP_KERNEL), nodemask=(null),cpuset=/,mems_allowed=0 If CONFIG_RANDOMIZE_BASE is set, the module region can be located in the vmalloc region entirely. Although module_alloc() can fall back to a 2GB window if ARM64_MODULE_PLTS is set, the module region is still easily exhausted because the module region is located at bottom of vmalloc region and the vmalloc region is allocated from bottom to top. Skip module region if not calling from module_alloc(). Signed-off-by: Liu Shixin <liushixin2(a)huawei.com> Signed-off-by: Zheng Zengkai <zhengzengkai(a)huawei.com> [cherry-pick from devel-6.1] Signed-off-by: Liu Shixin <liushixin2(a)huawei.com> --- arch/arm64/include/asm/vmalloc.h | 26 ++++++++++++++++++++++++++ include/linux/vmalloc.h | 9 +++++++++ mm/vmalloc.c | 4 ++++ 3 files changed, 39 insertions(+) diff --git a/arch/arm64/include/asm/vmalloc.h b/arch/arm64/include/asm/vmalloc.h index 38fafffe699f..4feff546b11b 100644 --- a/arch/arm64/include/asm/vmalloc.h +++ b/arch/arm64/include/asm/vmalloc.h @@ -31,4 +31,30 @@ static inline pgprot_t arch_vmap_pgprot_tagged(pgprot_t prot) return pgprot_tagged(prot); } +#ifdef CONFIG_RANDOMIZE_BASE +extern u64 module_alloc_base; +#define arch_vmap_skip_module_region arch_vmap_skip_module_region +static inline void arch_vmap_skip_module_region(unsigned long *addr, + unsigned long vstart, + unsigned long size, + unsigned long align) +{ + u64 module_alloc_end = module_alloc_base + MODULES_VSIZE; + + if (vstart == module_alloc_base) + return; + + if (IS_ENABLED(CONFIG_KASAN_GENERIC) || + IS_ENABLED(CONFIG_KASAN_SW_TAGS)) + /* don't exceed the static module region - see module_alloc() */ + module_alloc_end = MODULES_END; + + if ((module_alloc_base >= *addr + size) || + (module_alloc_end <= *addr)) + return; + + *addr = ALIGN(module_alloc_end, align); +} +#endif + #endif /* _ASM_ARM64_VMALLOC_H */ diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h index c720be70c8dd..a7b6c2183d55 100644 --- a/include/linux/vmalloc.h +++ b/include/linux/vmalloc.h @@ -124,6 +124,15 @@ static inline pgprot_t arch_vmap_pgprot_tagged(pgprot_t prot) } #endif +#ifndef arch_vmap_skip_module_region +static inline void arch_vmap_skip_module_region(unsigned long *addr, + unsigned long vstart, + unsigned long size, + unsigned long align) +{ +} +#endif + /* * Highlevel APIs for driver use */ diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 1d13d71687d7..afab3c7295b4 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -1230,6 +1230,8 @@ is_within_this_va(struct vmap_area *va, unsigned long size, else nva_start_addr = ALIGN(vstart, align); + arch_vmap_skip_module_region(&nva_start_addr, vstart, size, align); + /* Can be overflowed due to big size or alignment. */ if (nva_start_addr + size < nva_start_addr || nva_start_addr < vstart) @@ -1517,6 +1519,8 @@ __alloc_vmap_area(struct rb_root *root, struct list_head *head, else nva_start_addr = ALIGN(vstart, align); + arch_vmap_skip_module_region(&nva_start_addr, vstart, size, align); + /* Check the "vend" restriction. */ if (nva_start_addr + size > vend) return vend; -- 2.25.1

2 1

[PATCH OLK-5.10 0/4] Tracing fixes
by Zheng Yejian 18 Jul '23

18 Jul '23

Tracing fixes: - Fix a deadloop in reading trace_pipe that was caused by a mismatch between ring_buffer_empty() returning false which then asked to read the data, but the read code uses rb_num_of_entries() that returned zero, and causing an infinite "retry". - Fix a warning caused by not using all pages allocated to store ftrace functions, where this can happen if the linker inserts a bunch of "NULL" entries, causing the accounting of how many pages needed to be off. - Fix memory leak in freeing iter->temp in tracing_release_pipe(). Linus Torvalds (1): ftrace: Store the order of pages allocated in ftrace_page Zheng Yejian (3): ring-buffer: Fix deadloop issue on reading trace_pipe tracing: Fix memory leak of iter->temp when reading trace_pipe ftrace: Fix possible warning on checking all pages used in ftrace_process_locs() kernel/trace/ftrace.c | 72 +++++++++++++++++++++++--------------- kernel/trace/ring_buffer.c | 24 ++++++++----- kernel/trace/trace.c | 1 + 3 files changed, 60 insertions(+), 37 deletions(-) -- 2.25.1

2 5

[PATCH openEuler-1.0-LTS] KVM: fix overflow of zero page refcount with ksm running
by Lei Chen 18 Jul '23

18 Jul '23

From: Zhuang Yanying <ann.zhuangyanying(a)huawei.com> mainline inclusion from mainline-v5.10 commit 7df003c85218b5f5b10a7f6418208f31e813f38f category: bugfix -------------------------------- We are testing Virtual Machine with KSM on v5.4-rc2 kernel, and found the zero_page refcount overflow. The cause of refcount overflow is increased in try_async_pf (get_user_page) without being decreased in mmu_set_spte() while handling ept violation. In kvm_release_pfn_clean(), only unreserved page will call put_page. However, zero page is reserved. So, as well as creating and destroy vm, the refcount of zero page will continue to increase until it overflows. step1: echo 10000 > /sys/kernel/pages_to_scan/pages_to_scan echo 1 > /sys/kernel/pages_to_scan/run echo 1 > /sys/kernel/pages_to_scan/use_zero_pages step2: just create several normal qemu kvm vms. And destroy it after 10s. Repeat this action all the time. After a long period of time, all domains hang because of the refcount of zero page overflow. Qemu print error log as follow: â€¦ error: kvm run failed Bad address EAX=00006cdc EBX=00000008 ECX=80202001 EDX=078bfbfd ESI=ffffffff EDI=00000000 EBP=00000008 ESP=00006cc4 EIP=000efd75 EFL=00010002 [-------] CPL=0 II=0 A20=1 SMM=0 HLT=0 ES =0010 00000000 ffffffff 00c09300 DPL=0 DS [-WA] CS =0008 00000000 ffffffff 00c09b00 DPL=0 CS32 [-RA] SS =0010 00000000 ffffffff 00c09300 DPL=0 DS [-WA] DS =0010 00000000 ffffffff 00c09300 DPL=0 DS [-WA] FS =0010 00000000 ffffffff 00c09300 DPL=0 DS [-WA] GS =0010 00000000 ffffffff 00c09300 DPL=0 DS [-WA] LDT=0000 00000000 0000ffff 00008200 DPL=0 LDT TR =0000 00000000 0000ffff 00008b00 DPL=0 TSS32-busy GDT= 000f7070 00000037 IDT= 000f70ae 00000000 CR0=00000011 CR2=00000000 CR3=00000000 CR4=00000000 DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000 DR6=00000000ffff0ff0 DR7=0000000000000400 EFER=0000000000000000 Code=00 01 00 00 00 e9 e8 00 00 00 c7 05 4c 55 0f 00 01 00 00 00 <8b> 35 00 00 01 00 8b 3d 04 00 01 00 b8 d8 d3 00 00 c1 e0 08 0c ea a3 00 00 01 00 c7 05 04 â€¦ Meanwhile, a kernel warning is departed. [40914.836375] WARNING: CPU: 3 PID: 82067 at ./include/linux/mm.h:987 try_get_page+0x1f/0x30 [40914.836412] CPU: 3 PID: 82067 Comm: CPU 0/KVM Kdump: loaded Tainted: G OE 5.2.0-rc2 #5 [40914.836415] RIP: 0010:try_get_page+0x1f/0x30 [40914.836417] Code: 40 00 c3 0f 1f 84 00 00 00 00 00 48 8b 47 08 a8 01 75 11 8b 47 34 85 c0 7e 10 f0 ff 47 34 b8 01 00 00 00 c3 48 8d 78 ff eb e9 <0f> 0b 31 c0 c3 66 90 66 2e 0f 1f 84 00 0 0 00 00 00 48 8b 47 08 a8 [40914.836418] RSP: 0018:ffffb4144e523988 EFLAGS: 00010286 [40914.836419] RAX: 0000000080000000 RBX: 0000000000000326 RCX: 0000000000000000 [40914.836420] RDX: 0000000000000000 RSI: 00004ffdeba10000 RDI: ffffdf07093f6440 [40914.836421] RBP: ffffdf07093f6440 R08: 800000424fd91225 R09: 0000000000000000 [40914.836421] R10: ffff9eb41bfeebb8 R11: 0000000000000000 R12: ffffdf06bbd1e8a8 [40914.836422] R13: 0000000000000080 R14: 800000424fd91225 R15: ffffdf07093f6440 [40914.836423] FS: 00007fb60ffff700(0000) GS:ffff9eb4802c0000(0000) knlGS:0000000000000000 [40914.836425] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [40914.836426] CR2: 0000000000000000 CR3: 0000002f220e6002 CR4: 00000000003626e0 [40914.836427] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [40914.836427] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [40914.836428] Call Trace: [40914.836433] follow_page_pte+0x302/0x47b [40914.836437] __get_user_pages+0xf1/0x7d0 [40914.836441] ? irq_work_queue+0x9/0x70 [40914.836443] get_user_pages_unlocked+0x13f/0x1e0 [40914.836469] __gfn_to_pfn_memslot+0x10e/0x400 [kvm] [40914.836486] try_async_pf+0x87/0x240 [kvm] [40914.836503] tdp_page_fault+0x139/0x270 [kvm] [40914.836523] kvm_mmu_page_fault+0x76/0x5e0 [kvm] [40914.836588] vcpu_enter_guest+0xb45/0x1570 [kvm] [40914.836632] kvm_arch_vcpu_ioctl_run+0x35d/0x580 [kvm] [40914.836645] kvm_vcpu_ioctl+0x26e/0x5d0 [kvm] [40914.836650] do_vfs_ioctl+0xa9/0x620 [40914.836653] ksys_ioctl+0x60/0x90 [40914.836654] __x64_sys_ioctl+0x16/0x20 [40914.836658] do_syscall_64+0x5b/0x180 [40914.836664] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [40914.836666] RIP: 0033:0x7fb61cb6bfc7 Signed-off-by: LinFeng <linfeng23(a)huawei.com> Signed-off-by: Zhuang Yanying <ann.zhuangyanying(a)huawei.com> Signed-off-by: Paolo Bonzini <pbonzini(a)redhat.com> Signed-off-by: Lei Chen <lei.chen(a)smartx.com> --- virt/kvm/kvm_main.c | 1 + 1 file changed, 1 insertion(+) diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 96fb21ac7224..e4e3dc429ec4 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -170,6 +170,7 @@ bool kvm_is_reserved_pfn(kvm_pfn_t pfn) */ if (pfn_valid(pfn)) return PageReserved(pfn_to_page(pfn)) && + !is_zero_pfn(pfn) && !kvm_is_zone_device_pfn(pfn); return true; -- 2.34.1

2 1

[PATCH OLK-5.10] Fix the default return value of dm_pool_dec_data_range()
by Li Lingfeng 18 Jul '23

18 Jul '23

hulk inclusion category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I7LJO8 CVE: NA -------------------------------- Commit 26d0b2da7317 ("dm thin metadata: check fail_io before using data_sm") change the defalut return value of dm_pool_dec_data_range(), so fix it. Fixes: 26d0b2da7317 ("dm thin metadata: check fail_io before using data_sm") Signed-off-by: Li Lingfeng <lilingfeng3(a)huawei.com> --- drivers/md/dm-thin-metadata.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/md/dm-thin-metadata.c b/drivers/md/dm-thin-metadata.c index 69401bfac76e..551ae1cd3c43 100644 --- a/drivers/md/dm-thin-metadata.c +++ b/drivers/md/dm-thin-metadata.c @@ -1806,7 +1806,7 @@ int dm_pool_inc_data_range(struct dm_pool_metadata *pmd, dm_block_t b, dm_block_ int dm_pool_dec_data_range(struct dm_pool_metadata *pmd, dm_block_t b, dm_block_t e) { - int r = -EINVAL; + int r = 0; pmd_write_lock(pmd); if (!pmd->fail_io) { -- 2.31.1

2 1

[PATCH OLK-5.10] netfilter: nf_tables: prevent OOB access in nft_byteorder_eval
by Ziyang Xuan 18 Jul '23

18 Jul '23

From: Thadeu Lima de Souza Cascardo <cascardo(a)canonical.com> mainline inclusion from mainline-v6.5-rc2 commit caf3ef7468f7534771b5c44cd8dbd6f7f87c2cbd category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I7ISR1 CVE: CVE-2023-35001 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?… --------------------------- When evaluating byteorder expressions with size 2, a union with 32-bit and 16-bit members is used. Since the 16-bit members are aligned to 32-bit, the array accesses will be out-of-bounds. It may lead to a stack-out-of-bounds access like the one below: [ 23.095215] ================================================================== [ 23.095625] BUG: KASAN: stack-out-of-bounds in nft_byteorder_eval+0x13c/0x320 [ 23.096020] Read of size 2 at addr ffffc90000007948 by task ping/115 [ 23.096358] [ 23.096456] CPU: 0 PID: 115 Comm: ping Not tainted 6.4.0+ #413 [ 23.096770] Call Trace: [ 23.096910] <IRQ> [ 23.097030] dump_stack_lvl+0x60/0xc0 [ 23.097218] print_report+0xcf/0x630 [ 23.097388] ? nft_byteorder_eval+0x13c/0x320 [ 23.097577] ? kasan_addr_to_slab+0xd/0xc0 [ 23.097760] ? nft_byteorder_eval+0x13c/0x320 [ 23.097949] kasan_report+0xc9/0x110 [ 23.098106] ? nft_byteorder_eval+0x13c/0x320 [ 23.098298] __asan_load2+0x83/0xd0 [ 23.098453] nft_byteorder_eval+0x13c/0x320 [ 23.098659] nft_do_chain+0x1c8/0xc50 [ 23.098852] ? __pfx_nft_do_chain+0x10/0x10 [ 23.099078] ? __kasan_check_read+0x11/0x20 [ 23.099295] ? __pfx___lock_acquire+0x10/0x10 [ 23.099535] ? __pfx___lock_acquire+0x10/0x10 [ 23.099745] ? __kasan_check_read+0x11/0x20 [ 23.099929] nft_do_chain_ipv4+0xfe/0x140 [ 23.100105] ? __pfx_nft_do_chain_ipv4+0x10/0x10 [ 23.100327] ? lock_release+0x204/0x400 [ 23.100515] ? nf_hook.constprop.0+0x340/0x550 [ 23.100779] nf_hook_slow+0x6c/0x100 [ 23.100977] ? __pfx_nft_do_chain_ipv4+0x10/0x10 [ 23.101223] nf_hook.constprop.0+0x334/0x550 [ 23.101443] ? __pfx_ip_local_deliver_finish+0x10/0x10 [ 23.101677] ? __pfx_nf_hook.constprop.0+0x10/0x10 [ 23.101882] ? __pfx_ip_rcv_finish+0x10/0x10 [ 23.102071] ? __pfx_ip_local_deliver_finish+0x10/0x10 [ 23.102291] ? rcu_read_lock_held+0x4b/0x70 [ 23.102481] ip_local_deliver+0xbb/0x110 [ 23.102665] ? __pfx_ip_rcv+0x10/0x10 [ 23.102839] ip_rcv+0x199/0x2a0 [ 23.102980] ? __pfx_ip_rcv+0x10/0x10 [ 23.103140] __netif_receive_skb_one_core+0x13e/0x150 [ 23.103362] ? __pfx___netif_receive_skb_one_core+0x10/0x10 [ 23.103647] ? mark_held_locks+0x48/0xa0 [ 23.103819] ? process_backlog+0x36c/0x380 [ 23.103999] __netif_receive_skb+0x23/0xc0 [ 23.104179] process_backlog+0x91/0x380 [ 23.104350] __napi_poll.constprop.0+0x66/0x360 [ 23.104589] ? net_rx_action+0x1cb/0x610 [ 23.104811] net_rx_action+0x33e/0x610 [ 23.105024] ? _raw_spin_unlock+0x23/0x50 [ 23.105257] ? __pfx_net_rx_action+0x10/0x10 [ 23.105485] ? mark_held_locks+0x48/0xa0 [ 23.105741] __do_softirq+0xfa/0x5ab [ 23.105956] ? __dev_queue_xmit+0x765/0x1c00 [ 23.106193] do_softirq.part.0+0x49/0xc0 [ 23.106423] </IRQ> [ 23.106547] <TASK> [ 23.106670] __local_bh_enable_ip+0xf5/0x120 [ 23.106903] __dev_queue_xmit+0x789/0x1c00 [ 23.107131] ? __pfx___dev_queue_xmit+0x10/0x10 [ 23.107381] ? find_held_lock+0x8e/0xb0 [ 23.107585] ? lock_release+0x204/0x400 [ 23.107798] ? neigh_resolve_output+0x185/0x350 [ 23.108049] ? mark_held_locks+0x48/0xa0 [ 23.108265] ? neigh_resolve_output+0x185/0x350 [ 23.108514] neigh_resolve_output+0x246/0x350 [ 23.108753] ? neigh_resolve_output+0x246/0x350 [ 23.109003] ip_finish_output2+0x3c3/0x10b0 [ 23.109250] ? __pfx_ip_finish_output2+0x10/0x10 [ 23.109510] ? __pfx_nf_hook+0x10/0x10 [ 23.109732] __ip_finish_output+0x217/0x390 [ 23.109978] ip_finish_output+0x2f/0x130 [ 23.110207] ip_output+0xc9/0x170 [ 23.110404] ip_push_pending_frames+0x1a0/0x240 [ 23.110652] raw_sendmsg+0x102e/0x19e0 [ 23.110871] ? __pfx_raw_sendmsg+0x10/0x10 [ 23.111093] ? lock_release+0x204/0x400 [ 23.111304] ? __mod_lruvec_page_state+0x148/0x330 [ 23.111567] ? find_held_lock+0x8e/0xb0 [ 23.111777] ? find_held_lock+0x8e/0xb0 [ 23.111993] ? __rcu_read_unlock+0x7c/0x2f0 [ 23.112225] ? aa_sk_perm+0x18a/0x550 [ 23.112431] ? filemap_map_pages+0x4f1/0x900 [ 23.112665] ? __pfx_aa_sk_perm+0x10/0x10 [ 23.112880] ? find_held_lock+0x8e/0xb0 [ 23.113098] inet_sendmsg+0xa0/0xb0 [ 23.113297] ? inet_sendmsg+0xa0/0xb0 [ 23.113500] ? __pfx_inet_sendmsg+0x10/0x10 [ 23.113727] sock_sendmsg+0xf4/0x100 [ 23.113924] ? move_addr_to_kernel.part.0+0x4f/0xa0 [ 23.114190] __sys_sendto+0x1d4/0x290 [ 23.114391] ? __pfx___sys_sendto+0x10/0x10 [ 23.114621] ? __pfx_mark_lock.part.0+0x10/0x10 [ 23.114869] ? lock_release+0x204/0x400 [ 23.115076] ? find_held_lock+0x8e/0xb0 [ 23.115287] ? rcu_is_watching+0x23/0x60 [ 23.115503] ? __rseq_handle_notify_resume+0x6e2/0x860 [ 23.115778] ? __kasan_check_write+0x14/0x30 [ 23.116008] ? blkcg_maybe_throttle_current+0x8d/0x770 [ 23.116285] ? mark_held_locks+0x28/0xa0 [ 23.116503] ? do_syscall_64+0x37/0x90 [ 23.116713] __x64_sys_sendto+0x7f/0xb0 [ 23.116924] do_syscall_64+0x59/0x90 [ 23.117123] ? irqentry_exit_to_user_mode+0x25/0x30 [ 23.117387] ? irqentry_exit+0x77/0xb0 [ 23.117593] ? exc_page_fault+0x92/0x140 [ 23.117806] entry_SYSCALL_64_after_hwframe+0x6e/0xd8 [ 23.118081] RIP: 0033:0x7f744aee2bba [ 23.118282] Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb b8 0f 1f 00 f3 0f 1e fa 41 89 ca 64 8b 04 25 18 00 00 00 85 c0 75 15 b8 2c 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 7e c3 0f 1f 44 00 00 41 54 48 83 ec 30 44 89 [ 23.119237] RSP: 002b:00007ffd04a7c9f8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c [ 23.119644] RAX: ffffffffffffffda RBX: 00007ffd04a7e0a0 RCX: 00007f744aee2bba [ 23.120023] RDX: 0000000000000040 RSI: 000056488e9e6300 RDI: 0000000000000003 [ 23.120413] RBP: 000056488e9e6300 R08: 00007ffd04a80320 R09: 0000000000000010 [ 23.120809] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000040 [ 23.121219] R13: 00007ffd04a7dc38 R14: 00007ffd04a7ca00 R15: 00007ffd04a7e0a0 [ 23.121617] </TASK> [ 23.121749] [ 23.121845] The buggy address belongs to the virtual mapping at [ 23.121845] [ffffc90000000000, ffffc90000009000) created by: [ 23.121845] irq_init_percpu_irqstack+0x1cf/0x270 [ 23.122707] [ 23.122803] The buggy address belongs to the physical page: [ 23.123104] page:0000000072ac19f0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x24a09 [ 23.123609] flags: 0xfffffc0001000(reserved|node=0|zone=1|lastcpupid=0x1fffff) [ 23.123998] page_type: 0xffffffff() [ 23.124194] raw: 000fffffc0001000 ffffea0000928248 ffffea0000928248 0000000000000000 [ 23.124610] raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000 [ 23.125023] page dumped because: kasan: bad access detected [ 23.125326] [ 23.125421] Memory state around the buggy address: [ 23.125682] ffffc90000007800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 23.126072] ffffc90000007880: 00 00 00 00 00 f1 f1 f1 f1 f1 f1 00 00 f2 f2 00 [ 23.126455] >ffffc90000007900: 00 00 00 00 00 00 00 00 00 f2 f2 f2 f2 00 00 00 [ 23.126840] ^ [ 23.127138] ffffc90000007980: 00 00 00 00 00 00 00 00 00 00 00 00 00 f3 f3 f3 [ 23.127522] ffffc90000007a00: f3 00 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1 [ 23.127906] ================================================================== [ 23.128324] Disabling lock debugging due to kernel taint Using simple s16 pointers for the 16-bit accesses fixes the problem. For the 32-bit accesses, src and dst can be used directly. Fixes: 96518518cc41 ("netfilter: add nftables") Cc: stable(a)vger.kernel.org Reported-by: Tanguy DUBROCA (@SidewayRE) from @Synacktiv working with ZDI Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo(a)canonical.com> Reviewed-by: Florian Westphal <fw(a)strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo(a)netfilter.org> Signed-off-by: Ziyang Xuan <william.xuanziyang(a)huawei.com> --- net/netfilter/nft_byteorder.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/net/netfilter/nft_byteorder.c b/net/netfilter/nft_byteorder.c index 9d5947ab8d4e..7b0b8fecb220 100644 --- a/net/netfilter/nft_byteorder.c +++ b/net/netfilter/nft_byteorder.c @@ -30,11 +30,11 @@ void nft_byteorder_eval(const struct nft_expr *expr, const struct nft_byteorder *priv = nft_expr_priv(expr); u32 *src = &regs->data[priv->sreg]; u32 *dst = &regs->data[priv->dreg]; - union { u32 u32; u16 u16; } *s, *d; + u16 *s16, *d16; unsigned int i; - s = (void *)src; - d = (void *)dst; + s16 = (void *)src; + d16 = (void *)dst; switch (priv->size) { case 8: { @@ -61,11 +61,11 @@ void nft_byteorder_eval(const struct nft_expr *expr, switch (priv->op) { case NFT_BYTEORDER_NTOH: for (i = 0; i < priv->len / 4; i++) - d[i].u32 = ntohl((__force __be32)s[i].u32); + dst[i] = ntohl((__force __be32)src[i]); break; case NFT_BYTEORDER_HTON: for (i = 0; i < priv->len / 4; i++) - d[i].u32 = (__force __u32)htonl(s[i].u32); + dst[i] = (__force __u32)htonl(src[i]); break; } break; @@ -73,11 +73,11 @@ void nft_byteorder_eval(const struct nft_expr *expr, switch (priv->op) { case NFT_BYTEORDER_NTOH: for (i = 0; i < priv->len / 2; i++) - d[i].u16 = ntohs((__force __be16)s[i].u16); + d16[i] = ntohs((__force __be16)s16[i]); break; case NFT_BYTEORDER_HTON: for (i = 0; i < priv->len / 2; i++) - d[i].u16 = (__force __u16)htons(s[i].u16); + d16[i] = (__force __u16)htons(s16[i]); break; } break; -- 2.25.1

2 1

[PATCH OLK-5.10] anolis: bond: broadcast ARP or ND messages to all slaves
by Wang Yufen 18 Jul '23

18 Jul '23

From: Tony Lu <tonylu(a)linux.alibaba.com> anolis inclusion from devel-5.10-v5.10.134-12 commit b90e28f7170e1ae40c572f9f80a50bbdc8f8b99f category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I697AN CVE: NA Reference: https://gitee.com/anolis/cloud-kernel/commit/b90e28f7170e1ae40c572f9f80a50b… --------------------------- OpenAnolis Bug Tracker:0000282 This is achieved by broadcasting ARP or ND packets to all of its slave devices on transmit side. The switch will take further actions based on proper configuration. A new sysctl knob "net.bonding.broadcast_arp_or_nd" is introduced which controls the behaviour of broadcasting. Signed-off-by: Tony Lu <tonylu(a)linux.alibaba.com> Acked-by: Dust Li <dust.li(a)linux.alibaba.com> Signed-off-by: Qiao Ma <mqaio(a)linux.alibaba.com> Reviewed-by: Shile Zhang <shile.zhang(a)linux.alibaba.com> Acked-by: Dust Li <dust.li(a)linux.alibaba.com> Signed-off-by: Wang Yufen <wangyufen(a)huawei.com> Signed-off-by: Wang Yufen <wangyufen(a)huawei.com> --- Documentation/networking/ip-sysctl.rst | 11 ++++++++++ drivers/net/bonding/Makefile | 2 +- drivers/net/bonding/bond_main.c | 40 ++++++++++++++++++++++++++++++++++ drivers/net/bonding/bond_sysctl.c | 32 +++++++++++++++++++++++++++ include/net/bonding.h | 4 ++++ 5 files changed, 88 insertions(+), 1 deletion(-) create mode 100644 drivers/net/bonding/bond_sysctl.c diff --git a/Documentation/networking/ip-sysctl.rst b/Documentation/networking/ip-sysctl.rst index df26cf4..b27b887 100644 --- a/Documentation/networking/ip-sysctl.rst +++ b/Documentation/networking/ip-sysctl.rst @@ -2665,3 +2665,14 @@ max_dgram_qlen - INTEGER Default: 10 + +``/proc/sys/net/bonding/*`` +======================== + +broadcast_arp_or_nd - INTEGER + Control broadcasting ARP or ND messages to all slaves + + 0: Not broadcasting + 1: Broadcasting + + Default: 0 diff --git a/drivers/net/bonding/Makefile b/drivers/net/bonding/Makefile index 30e8ae3..9dd55d9 100644 --- a/drivers/net/bonding/Makefile +++ b/drivers/net/bonding/Makefile @@ -5,7 +5,7 @@ obj-$(CONFIG_BONDING) += bonding.o -bonding-objs := bond_main.o bond_3ad.o bond_alb.o bond_sysfs.o bond_sysfs_slave.o bond_debugfs.o bond_netlink.o bond_options.o +bonding-objs := bond_main.o bond_3ad.o bond_alb.o bond_sysfs.o bond_sysfs_slave.o bond_debugfs.o bond_netlink.o bond_options.o bond_sysctl.o proc-$(CONFIG_PROC_FS) += bond_procfs.o bonding-objs += $(proc-y) diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c index 1610067..ec0a4d942 100644 --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -4559,6 +4559,39 @@ int bond_update_slave_arr(struct bonding *bond, struct slave *skipslave) return ret; } +/* Check whether the skb is arp or nd msg */ +static inline bool skb_is_arp_or_nd(struct sk_buff *skb) +{ + switch (ntohs(skb->protocol)) { + case ETH_P_ARP: + return true; + case ETH_P_IPV6: + if (pskb_may_pull(skb, sizeof(struct ipv6hdr) + + sizeof(struct nd_msg))) { + struct ipv6hdr *hdr = ipv6_hdr(skb); + u8 nexthdr = hdr->nexthdr; + struct icmp6hdr *icmp6; + + if (nexthdr == IPPROTO_ICMPV6) { + icmp6 = icmp6_hdr(skb); + + if ((icmp6->icmp6_type == + NDISC_NEIGHBOUR_SOLICITATION || + icmp6->icmp6_type == + NDISC_NEIGHBOUR_ADVERTISEMENT) && + icmp6->icmp6_code == 0) { + return true; + } + } + } + } + + return false; +} + +static netdev_tx_t bond_xmit_broadcast(struct sk_buff *skb, + struct net_device *bond_dev); + static struct slave *bond_xmit_3ad_xor_slave_get(struct bonding *bond, struct sk_buff *skb, struct bond_up_slave *slaves) @@ -4587,6 +4620,10 @@ static netdev_tx_t bond_3ad_xor_xmit(struct sk_buff *skb, struct bond_up_slave *slaves; struct slave *slave; + /* Broadcast to all slaves. */ + if (sysctl_bond_broadcast_arp_or_nd && skb_is_arp_or_nd(skb)) + return bond_xmit_broadcast(skb, dev); + slaves = rcu_dereference(bond->usable_slaves); slave = bond_xmit_3ad_xor_slave_get(bond, skb, slaves); if (likely(slave)) @@ -5503,6 +5540,7 @@ static int __init bonding_init(void) goto err_link; bond_create_debugfs(); + bond_create_sysctl(); for (i = 0; i < max_bonds; i++) { res = bond_create(&init_net, NULL); @@ -5519,6 +5557,7 @@ static int __init bonding_init(void) return res; err: bond_destroy_debugfs(); + bond_destroy_sysctl(); bond_netlink_fini(); err_link: unregister_pernet_subsys(&bond_net_ops); @@ -5531,6 +5570,7 @@ static void __exit bonding_exit(void) unregister_netdevice_notifier(&bond_netdev_notifier); bond_destroy_debugfs(); + bond_destroy_sysctl(); bond_netlink_fini(); unregister_pernet_subsys(&bond_net_ops); diff --git a/drivers/net/bonding/bond_sysctl.c b/drivers/net/bonding/bond_sysctl.c new file mode 100644 index 0000000..17404d3 --- /dev/null +++ b/drivers/net/bonding/bond_sysctl.c @@ -0,0 +1,32 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <net/net_namespace.h> +#include <linux/sysctl.h> +#include <net/bonding.h> + +int sysctl_bond_broadcast_arp_or_nd __read_mostly; +EXPORT_SYMBOL(sysctl_bond_broadcast_arp_or_nd); + +struct ctl_table_header *bond_broadcast_arp_or_nd_table_header; + +static struct ctl_table bond_broadcast_arp_or_nd_table[] = { + { + .procname = "broadcast_arp_or_nd", + .data = &sysctl_bond_broadcast_arp_or_nd, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + }, + {} +}; + +void bond_create_sysctl(void) +{ + bond_broadcast_arp_or_nd_table_header = + register_net_sysctl(&init_net, "net/bonding", + bond_broadcast_arp_or_nd_table); +} + +void bond_destroy_sysctl(void) +{ + unregister_net_sysctl_table(bond_broadcast_arp_or_nd_table_header); +} diff --git a/include/net/bonding.h b/include/net/bonding.h index d9cc3f5..467c9da 100644 --- a/include/net/bonding.h +++ b/include/net/bonding.h @@ -114,6 +114,8 @@ static inline int is_netpoll_tx_blocked(struct net_device *dev) #define is_netpoll_tx_blocked(dev) (0) #endif +extern int sysctl_bond_broadcast_arp_or_nd; + struct bond_params { int mode; int xmit_policy; @@ -659,6 +661,8 @@ struct bond_vlan_tag *bond_verify_device_path(struct net_device *start_dev, int bond_update_slave_arr(struct bonding *bond, struct slave *skipslave); void bond_slave_arr_work_rearm(struct bonding *bond, unsigned long delay); void bond_work_init_all(struct bonding *bond); +void bond_create_sysctl(void); +void bond_destroy_sysctl(void); #ifdef CONFIG_PROC_FS void bond_create_proc_entry(struct bonding *bond); -- 1.8.3.1

2 1

[PATCH 4.19 1/2] ring-buffer: Fix deadloop issue on reading trace_pipe
by Yongqiang Liu 18 Jul '23

18 Jul '23

From: Zheng Yejian <zhengyejian1(a)huawei.com> mainline inclusion from mainline-v6.5-rc2 commit 7e42907f3a7b4ce3a2d1757f6d78336984daf8f5 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I7KXY9 CVE: NA Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?… --------------------------- Soft lockup occurs when reading file 'trace_pipe': watchdog: BUG: soft lockup - CPU#6 stuck for 22s! [cat:4488] [...] RIP: 0010:ring_buffer_empty_cpu+0xed/0x170 RSP: 0018:ffff88810dd6fc48 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000246 RCX: ffffffff93d1aaeb RDX: ffff88810a280040 RSI: 0000000000000008 RDI: ffff88811164b218 RBP: ffff88811164b218 R08: 0000000000000000 R09: ffff88815156600f R10: ffffed102a2acc01 R11: 0000000000000001 R12: 0000000051651901 R13: 0000000000000000 R14: ffff888115e49500 R15: 0000000000000000 [...] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f8d853c2000 CR3: 000000010dcd8000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __find_next_entry+0x1a8/0x4b0 ? peek_next_entry+0x250/0x250 ? down_write+0xa5/0x120 ? down_write_killable+0x130/0x130 trace_find_next_entry_inc+0x3b/0x1d0 tracing_read_pipe+0x423/0xae0 ? tracing_splice_read_pipe+0xcb0/0xcb0 vfs_read+0x16b/0x490 ksys_read+0x105/0x210 ? __ia32_sys_pwrite64+0x200/0x200 ? switch_fpu_return+0x108/0x220 do_syscall_64+0x33/0x40 entry_SYSCALL_64_after_hwframe+0x61/0xc6 Through the vmcore, I found it's because in tracing_read_pipe(), ring_buffer_empty_cpu() found some buffer is not empty but then it cannot read anything due to "rb_num_of_entries() == 0" always true, Then it infinitely loop the procedure due to user buffer not been filled, see following code path: tracing_read_pipe() { ... ... waitagain: tracing_wait_pipe() // 1. find non-empty buffer here trace_find_next_entry_inc() // 2. loop here try to find an entry __find_next_entry() ring_buffer_empty_cpu(); // 3. find non-empty buffer peek_next_entry() // 4. but peek always return NULL ring_buffer_peek() rb_buffer_peek() rb_get_reader_page() // 5. because rb_num_of_entries() == 0 always true here // then return NULL // 6. user buffer not been filled so goto 'waitgain' // and eventually leads to an deadloop in kernel!!! } By some analyzing, I found that when resetting ringbuffer, the 'entries' of its pages are not all cleared (see rb_reset_cpu()). Then when reducing the ringbuffer, and if some reduced pages exist dirty 'entries' data, they will be added into 'cpu_buffer->overrun' (see rb_remove_pages()), which cause wrong 'overrun' count and eventually cause the deadloop issue. To fix it, we need to clear every pages in rb_reset_cpu(). Link: https://lore.kernel.org/linux-trace-kernel/20230708225144.3785600-1-zhengye… Cc: stable(a)vger.kernel.org Fixes: a5fb833172eca ("ring-buffer: Fix uninitialized read_stamp") Signed-off-by: Zheng Yejian <zhengyejian1(a)huawei.com> Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org> Reviewed-by: Xu Kuohai <xukuohai(a)huawei.com> Signed-off-by: Yongqiang Liu <liuyongqiang13(a)huawei.com> --- kernel/trace/ring_buffer.c | 24 +++++++++++++++--------- 1 file changed, 15 insertions(+), 9 deletions(-) diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 3f098e32a7df..176777060349 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -4407,28 +4407,34 @@ unsigned long ring_buffer_size(struct ring_buffer *buffer, int cpu) } EXPORT_SYMBOL_GPL(ring_buffer_size); +static void rb_clear_buffer_page(struct buffer_page *page) +{ + local_set(&page->write, 0); + local_set(&page->entries, 0); + rb_init_page(page->page); + page->read = 0; +} + static void rb_reset_cpu(struct ring_buffer_per_cpu *cpu_buffer) { + struct buffer_page *page; + rb_head_page_deactivate(cpu_buffer); cpu_buffer->head_page = list_entry(cpu_buffer->pages, struct buffer_page, list); - local_set(&cpu_buffer->head_page->write, 0); - local_set(&cpu_buffer->head_page->entries, 0); - local_set(&cpu_buffer->head_page->page->commit, 0); - - cpu_buffer->head_page->read = 0; + rb_clear_buffer_page(cpu_buffer->head_page); + list_for_each_entry(page, cpu_buffer->pages, list) { + rb_clear_buffer_page(page); + } cpu_buffer->tail_page = cpu_buffer->head_page; cpu_buffer->commit_page = cpu_buffer->head_page; INIT_LIST_HEAD(&cpu_buffer->reader_page->list); INIT_LIST_HEAD(&cpu_buffer->new_pages); - local_set(&cpu_buffer->reader_page->write, 0); - local_set(&cpu_buffer->reader_page->entries, 0); - local_set(&cpu_buffer->reader_page->page->commit, 0); - cpu_buffer->reader_page->read = 0; + rb_clear_buffer_page(cpu_buffer->reader_page); local_set(&cpu_buffer->entries_bytes, 0); local_set(&cpu_buffer->overrun, 0); -- 2.25.1

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