syzbot


BUG: soft lockup in chrdev_open

Status: auto-obsoleted due to no activity on 2024/02/14 17:22
Reported-by: syzbot+5c6a914efbe6ca9078de@syzkaller.appspotmail.com
First crash: 196d, last: 196d
Similar bugs (6)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.19 INFO: rcu detected stall in chrdev_open (3) C error 17 601d 1155d 0/1 upstream: reported C repro on 2021/03/22 19:09
linux-4.14 INFO: rcu detected stall in chrdev_open C error 4 776d 881d 0/1 upstream: reported C repro on 2021/12/21 07:54
upstream INFO: rcu detected stall in chrdev_open (3) kernel 1 540d 540d 0/26 auto-obsoleted due to no activity on 2023/02/09 20:53
upstream INFO: rcu detected stall in chrdev_open (5) serial 1 212d 212d 0/26 auto-obsoleted due to no activity on 2024/01/19 06:34
upstream INFO: rcu detected stall in chrdev_open (4) media 1 315d 315d 0/26 auto-obsoleted due to no activity on 2023/10/08 11:46
upstream INFO: rcu detected stall in chrdev_open (2) serial C done inconclusive 55 853d 1620d 0/26 closed as invalid on 2022/02/08 10:45

Sample crash report:
watchdog: BUG: soft lockup - CPU#0 stuck for 29s! [syz-executor.2:9030]
Modules linked in:
irq event stamp: 7192
hardirqs last  enabled at (7191): [<ffff800011a46af8>] __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline]
hardirqs last  enabled at (7191): [<ffff800011a46af8>] _raw_spin_unlock_irqrestore+0xac/0x158 kernel/locking/spinlock.c:194
hardirqs last disabled at (7192): [<ffff80001196f560>] enter_el1_irq_or_nmi+0x10/0x1c arch/arm64/kernel/entry-common.c:227
softirqs last  enabled at (7166): [<ffff800008020ccc>] softirq_handle_end kernel/softirq.c:401 [inline]
softirqs last  enabled at (7166): [<ffff800008020ccc>] __do_softirq+0xb5c/0xe20 kernel/softirq.c:587
softirqs last disabled at (7161): [<ffff8000081b5750>] do_softirq_own_stack include/asm-generic/softirq_stack.h:10 [inline]
softirqs last disabled at (7161): [<ffff8000081b5750>] invoke_softirq kernel/softirq.c:439 [inline]
softirqs last disabled at (7161): [<ffff8000081b5750>] __irq_exit_rcu+0x28c/0x534 kernel/softirq.c:637
CPU: 0 PID: 9030 Comm: syz-executor.2 Not tainted 5.15.137-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline]
pc : _raw_spin_unlock_irqrestore+0xbc/0x158 kernel/locking/spinlock.c:194
lr : __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline]
lr : _raw_spin_unlock_irqrestore+0xac/0x158 kernel/locking/spinlock.c:194
sp : ffff80001ec77190
x29: ffff80001ec771a0 x28: 1ffff00003d8ee4c x27: 1ffff00003d8ee4d
x26: dfff800000000000 x25: 0000000000000003 x24: 0000000000000000
x23: ffff0000ca5d00c0 x22: ffff80000ab45a5c x21: ffff0000c0e9c160
x20: ffff0000c0e9c148 x19: 0000000000000000 x18: 1fffe000368fe78e
x17: 1fffe000368fe78e x16: ffff8000082eb4c0 x15: ffff8000149becc0
x14: 1ffff0000292406a x13: ffffffffffffffff x12: 0000000000040000
x11: 000000000003ffff x10: 0000000000000003 x9 : 0000000000000080
x8 : 00000000000000c0 x7 : 0000000000000000 x6 : 0000000000000000
x5 : 0000000000000080 x4 : 0000000000000000 x3 : ffff800008045860
x2 : 0000000000000006 x1 : ffff800011acab40 x0 : ffff80019ff83000
Call trace:
 arch_local_irq_restore arch/arm64/include/asm/irqflags.h:122 [inline]
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline]
 _raw_spin_unlock_irqrestore+0xbc/0x158 kernel/locking/spinlock.c:194
 spin_unlock_irqrestore include/linux/spinlock.h:418 [inline]
 klist_next+0x1ec/0x2f4 lib/klist.c:401
 class_dev_iter_next drivers/base/class.c:316 [inline]
 class_find_device+0x17c/0x290 drivers/base/class.c:420
 class_find_device_by_devt include/linux/device/class.h:167 [inline]
 tty_get_device drivers/tty/tty_io.c:3108 [inline]
 alloc_tty_struct+0x570/0x6bc drivers/tty/tty_io.c:3155
 pty_common_install+0x154/0x684 drivers/tty/pty.c:379
 pty_unix98_install+0x2c/0x3c drivers/tty/pty.c:721
 tty_driver_install_tty drivers/tty/tty_io.c:1317 [inline]
 tty_init_dev+0xb4/0x420 drivers/tty/tty_io.c:1431
 ptmx_open+0xfc/0x2e0 drivers/tty/pty.c:824
 chrdev_open+0x3e8/0x4fc fs/char_dev.c:414
 do_dentry_open+0x780/0xed8 fs/open.c:826
 vfs_open+0x7c/0x90 fs/open.c:956
 do_open fs/namei.c:3538 [inline]
 path_openat+0x1f28/0x26f0 fs/namei.c:3672
 do_filp_open+0x1a8/0x3b4 fs/namei.c:3699
 do_sys_openat2+0x128/0x3d8 fs/open.c:1211
 do_sys_open fs/open.c:1227 [inline]
 __do_sys_openat fs/open.c:1243 [inline]
 __se_sys_openat fs/open.c:1238 [inline]
 __arm64_sys_openat+0x1f0/0x240 fs/open.c:1238
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
 el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608
 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626
 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/11/06 17:22 linux-5.15.y 12952a23a5da 78fae24e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 BUG: soft lockup in chrdev_open
* Struck through repros no longer work on HEAD.