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BUG: soft lockup in pipe_read

Status: upstream: reported syz repro on 2024/01/25 02:05
Subsystems: fs mm
[Documentation on labels]
Reported-by: syzbot+8b31216d2ea3f2c6905b@syzkaller.appspotmail.com
First crash: 880d, last: 499d
▶ ▼ ✨ AI Jobs (4)
ID Workflow Result Correct Bug Created Started Finished Revision Error
dee785e9-b1aa-4ab3-bae8-8093b11d4202 assessment-security 💥 BUG: soft lockup in pipe_read 2026/06/14 03:32 2026/06/14 03:32 2026/06/14 03:52 4f06757f683a802254a4c8edbfe67ff801904c5e 
failed to run ["make" "KERNELVERSION=syzkaller" "KERNELRELEASE=syzkaller" "LOCALVERSION=-syzkaller" "-j" "32" "ARCH=arm64" "CROSS_COMPILE=aarch64-linux-gnu-" "CC=ccache clang" "LD=ld.lld" "O=/app/work...
truncated to first 200 bytes; open job for full error
d6ad89be-6a86-4a69-9876-38d64f8a2838 assessment-security 💥 BUG: soft lockup in pipe_read 2026/06/09 19:12 2026/06/09 19:12 2026/06/09 19:41 c36c07f6c1f2230a36374cbd22235f635e8f9284 
failed to run ["make" "KERNELVERSION=syzkaller" "KERNELRELEASE=syzkaller" "LOCALVERSION=-syzkaller" "-j" "32" "ARCH=arm64" "CROSS_COMPILE=aarch64-linux-gnu-" "CC=ccache clang" "LD=ld.lld" "O=/app/work...
truncated to first 200 bytes; open job for full error
b1ab65c9-4b9c-4091-92c7-2041e7bc34cb assessment-security 💥 BUG: soft lockup in pipe_read 2026/06/02 18:11 2026/06/02 18:11 2026/06/02 18:44 62fe15281f5011cd203d8845b8767b10e7443aa5 
failed to run ["make" "KERNELVERSION=syzkaller" "KERNELRELEASE=syzkaller" "LOCALVERSION=-syzkaller" "-j" "32" "ARCH=x86_64" "CC=ccache clang" "LD=ld.lld" "O=/app/workdir/cache/build/ddc9086063c9b51b1c...
truncated to first 200 bytes; open job for full error
30be771c-9661-4c2b-9867-eabfacf224b1 assessment-security 💥 BUG: soft lockup in pipe_read 2026/05/26 12:48 2026/05/26 12:48 2026/05/26 13:06 c69befb30ac10e158cc9d1557b508ee3f0eca1de 
failed to run ["make" "KERNELVERSION=syzkaller" "KERNELRELEASE=syzkaller" "LOCALVERSION=-syzkaller" "-j" "32" "ARCH=x86_64" "CC=ccache clang" "LD=ld.lld" "O=/app/workdir/cache/build/ddc9086063c9b51b1c...
truncated to first 200 bytes; open job for full error
▶ ▼ Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [fs?] BUG: soft lockup in pipe_read 0 (1) 2024/01/25 02:05
▶ ▼ Similar bugs (2)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in pipe_read (2) kasan mm 1 1 1466d 1466d 0/29 auto-closed as invalid on 2022/09/12 02:39
upstream INFO: rcu detected stall in pipe_read mm 1 6 2354d 2390d 0/29 closed as dup on 2019/12/03 08:34
▶ ▼ Last patch testing requests (10)
Created Duration User Patch Repo Result
2026/05/31 06:10 55m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci report log
2026/04/17 01:57 3h49m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci error
2026/03/21 19:19 26m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci error
2026/02/05 17:10 28m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci error
2026/01/10 15:25 43m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci report log
2025/11/27 14:55 1h43m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci report log
2025/11/01 06:55 1h27m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci report log
2025/09/18 11:15 21m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci report log
2025/08/23 00:59 27m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci report log
2025/07/10 07:57 22m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci report log

Sample crash report:
watchdog: BUG: soft lockup - CPU#0 stuck for 21s! [syz-executor:6638]
Modules linked in:
irq event stamp: 4860
hardirqs last  enabled at (4859): [<ffff80008b8294d8>] __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:151 [inline]
hardirqs last  enabled at (4859): [<ffff80008b8294d8>] _raw_spin_unlock_irqrestore+0x38/0x98 kernel/locking/spinlock.c:194
hardirqs last disabled at (4860): [<ffff80008b8056d0>] __el1_irq arch/arm64/kernel/entry-common.c:557 [inline]
hardirqs last disabled at (4860): [<ffff80008b8056d0>] el1_interrupt+0x24/0x68 arch/arm64/kernel/entry-common.c:575
softirqs last  enabled at (4700): [<ffff800080129934>] local_bh_enable+0x10/0x34 include/linux/bottom_half.h:32
softirqs last disabled at (4698): [<ffff800080129900>] local_bh_disable+0x10/0x34 include/linux/bottom_half.h:19
CPU: 0 UID: 0 PID: 6638 Comm: syz-executor Not tainted 6.14.0-rc1-syzkaller-g2014c95afece #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : __pi_memset_generic+0x78/0x188 arch/arm64/lib/memset.S:96
lr : __asan_memset+0x48/0x64 mm/kasan/shadow.c:87
sp : ffff8000a9f47690
x29: ffff8000a9f47690 x28: ffff0000d6982959 x27: 0000000000000000
x26: dfff800000000000 x25: 1fffe0001ad30526 x24: ffff0000d6982930
x23: 1fffe0001ad30529 x22: dfff800000000000 x21: ffff8000a9f477d0
x20: 0000000000000000 x19: 0000000000000010 x18: 0000000000000000
x17: 0000000000000000 x16: ffff80008b769d48 x15: 0000000000000002
x14: 1ffff000153e8efa x13: 0000000000000000 x12: 0000000000000000
x11: ffff7000153e8efc x10: 1ffff000153e8efb x9 : dfff800000000000
x8 : ffff8000a9f477d0 x7 : 0000000000000000 x6 : 0000000000000000
x5 : 0000000000000000 x4 : 0000000000000000 x3 : 0000000000000010
x2 : 0000000000000010 x1 : 0000000000000000 x0 : ffff8000a9f477d0
Call trace:
 __pi_memset_generic+0x78/0x188 arch/arm64/lib/memset.S:95 (P)
 __schedule+0xb8/0x257c kernel/sched/core.c:6654
 __schedule_loop kernel/sched/core.c:6841 [inline]
 schedule+0xbc/0x238 kernel/sched/core.c:6856
 pipe_read+0x9e4/0xee0 fs/pipe.c:391
 new_sync_read fs/read_write.c:484 [inline]
 vfs_read+0x698/0x974 fs/read_write.c:565
 ksys_read+0x15c/0x26c fs/read_write.c:708
 __do_sys_read fs/read_write.c:717 [inline]
 __se_sys_read fs/read_write.c:715 [inline]
 __arm64_sys_read+0x7c/0x90 fs/read_write.c:715
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
 el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:744
 el0t_64_sync_handler+0x84/0x108 arch/arm64/kernel/entry-common.c:762
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted 6.14.0-rc1-syzkaller-g2014c95afece #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : arch_local_irq_enable+0x8/0xc arch/arm64/include/asm/irqflags.h:50
lr : default_idle_call+0xf8/0x128 kernel/sched/idle.c:124
sp : ffff800097dc7d10
x29: ffff800097dc7d10 x28: dfff800000000000 x27: 1ffff00012fb8fb0
x26: ffff80008fbcd000 x25: 0000000000000000 x24: 0000000000000002
x23: 1ffff00011f79ac0 x22: ffff80008fbcd600 x21: 0000000000000000
x20: ffff0000c1b88000 x19: ffff800080410fc8 x18: 1fffe000366f6486
x17: ffff80008fbcd000 x16: ffff8000804108a8 x15: 0000000000000001
x14: 1fffe000366f812f x13: 0000000000000000 x12: 0000000000000003
x11: 0000000000000001 x10: 0000000000000003 x9 : 0000000000000000
x8 : 00000000000581fd x7 : ffff8000805c3da8 x6 : 0000000000000000
x5 : 0000000000000001 x4 : 0000000000000001 x3 : ffff80008b809fe0
x2 : 0000000000000000 x1 : ffff80008b8ba180 x0 : ffff800123c9a000
Call trace:
 __daif_local_irq_enable arch/arm64/include/asm/irqflags.h:26 [inline] (P)
 arch_local_irq_enable+0x8/0xc arch/arm64/include/asm/irqflags.h:48 (P)
 cpuidle_idle_call kernel/sched/idle.c:185 [inline]
 do_idle+0x1ec/0x4e0 kernel/sched/idle.c:325
 cpu_startup_entry+0x5c/0x74 kernel/sched/idle.c:423
 secondary_start_kernel+0x1bc/0x1e4 arch/arm64/kernel/smp.c:279
 __secondary_switched+0xc0/0xc4 arch/arm64/kernel/head.S:417

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/02/05 11:06 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 2014c95afece 5896748e .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 BUG: soft lockup in pipe_read
2024/01/21 01:56 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 0802e17d9aca 9bd8dcda .config console log report syz [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 BUG: soft lockup in pipe_read
2024/06/13 02:09 linux-next a957267fa7e9 2aa5052f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: rcu detected stall in pipe_read
2024/05/29 03:32 linux-next 6dc544b66971 34889ee3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: rcu detected stall in pipe_read
2024/05/29 03:28 linux-next 6dc544b66971 34889ee3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: rcu detected stall in pipe_read
* Struck through repros no longer work on HEAD.