syzbot

 sign-in | mailing list | source | docs
🐞 Open [125]
🐞 Fixed [23]
🐞 Invalid [370]
≡ Crashes
Kernel Health Bugs/Month Bug Lifetimes Fuzzing
💬 Send us feedback

BUG: soft lockup in kernfs_fop_read_iter

Status: auto-obsoleted due to no activity on 2024/08/04 18:27
Reported-by: syzbot+4810ca595049fe673a51@syzkaller.appspotmail.com
First crash: 766d, last: 766d
▶ ▼ Similar bugs (5)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in kernfs_fop_read_iter kernel 1 1 1406d 1406d 0/29 auto-obsoleted due to no activity on 2022/11/04 01:43
upstream INFO: rcu detected stall in kernfs_fop_read_iter (3) kernfs 1 6 721d 900d 0/29 auto-obsoleted due to no activity on 2024/09/18 21:50
upstream INFO: rcu detected stall in kernfs_fop_read_iter (2) kernel 1 1 1114d 1114d 0/29 auto-obsoleted due to no activity on 2023/08/22 18:06
upstream INFO: rcu detected stall in kernfs_fop_read_iter (4) usb 1 syz 14 418d 621d 0/29 auto-obsoleted due to no activity on 2025/07/28 14:35
upstream INFO: rcu detected stall in kernfs_fop_read_iter (5) mm 1 2 111d 165d 0/29 auto-obsoleted due to no activity on 2026/05/21 13:14

Sample crash report:
RBP: 00005628af8fcf70 R08: 000000000000000c R09: 0000000000000000
R10: 000000000000010f R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000003fff R14: 00007ffddffe9a38 R15: 000000000000000a
 </TASK>
watchdog: BUG: soft lockup - CPU#0 stuck for 225s! [udevd:100]
Modules linked in:
CPU: 0 PID: 100 Comm: udevd Not tainted 5.15.149-syzkaller-00490-g5d96939590c0 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
RIP: 0010:native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
RIP: 0010:arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
RIP: 0010:kvm_wait+0x147/0x180 arch/x86/kernel/kvm.c:918
Code: 4c 89 e8 48 c1 e8 03 42 0f b6 04 20 84 c0 44 8b 74 24 1c 75 34 41 0f b6 45 00 44 38 f0 75 10 66 90 0f 00 2d 5b 03 f3 03 fb f4 <e9> 24 ff ff ff fb e9 1e ff ff ff 44 89 e9 80 e1 07 38 c1 7c a3 4c
RSP: 0018:ffffc900009b7220 EFLAGS: 00000246
RAX: 0000000000000003 RBX: 1ffff92000136e48 RCX: ffffffff8154fa7f
RDX: dffffc0000000000 RSI: 0000000000000003 RDI: ffff88810de8c288
RBP: ffffc900009b72d0 R08: dffffc0000000000 R09: ffffed1021bd1852
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: ffff88810de8c288 R14: 0000000000000003 R15: 1ffff92000136e4c
FS:  00007f1e3d5e0c80(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555557229818 CR3: 000000010cd17000 CR4: 00000000003506b0
Call Trace:
 <IRQ>
 </IRQ>
 <TASK>
 pv_wait arch/x86/include/asm/paravirt.h:597 [inline]
 pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:470 [inline]
 __pv_queued_spin_lock_slowpath+0x6bc/0xc40 kernel/locking/qspinlock.c:508
 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:585 [inline]
 queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline]
 queued_spin_lock include/asm-generic/qspinlock.h:85 [inline]
 do_raw_spin_lock include/linux/spinlock.h:187 [inline]
 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:136 [inline]
 _raw_spin_lock_bh+0x139/0x1b0 kernel/locking/spinlock.c:178
 sock_hash_delete_elem+0xb1/0x2f0 net/core/sock_map.c:937
 bpf_prog_2c29ac5cdc6b1842+0x3a/0xc20
 bpf_dispatcher_nop_func include/linux/bpf.h:785 [inline]
 __bpf_prog_run include/linux/filter.h:625 [inline]
 bpf_prog_run include/linux/filter.h:632 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:1883 [inline]
 bpf_trace_run2+0xec/0x210 kernel/trace/bpf_trace.c:1920
 __bpf_trace_kfree+0x6f/0x90 include/trace/events/kmem.h:118
 trace_kfree include/trace/events/kmem.h:118 [inline]
 kfree+0x1f3/0x220 mm/slub.c:4569
 sk_psock_free_link include/linux/skmsg.h:420 [inline]
 sock_map_del_link net/core/sock_map.c:160 [inline]
 sock_map_unref+0x352/0x4d0 net/core/sock_map.c:182
 sock_hash_delete_elem+0x274/0x2f0 net/core/sock_map.c:941
 bpf_prog_2c29ac5cdc6b1842+0x3a/0xc20
 bpf_dispatcher_nop_func include/linux/bpf.h:785 [inline]
 __bpf_prog_run include/linux/filter.h:625 [inline]
 bpf_prog_run include/linux/filter.h:632 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:1883 [inline]
 bpf_trace_run2+0xec/0x210 kernel/trace/bpf_trace.c:1920
 __bpf_trace_kfree+0x6f/0x90 include/trace/events/kmem.h:118
 trace_kfree include/trace/events/kmem.h:118 [inline]
 kfree+0x1f3/0x220 mm/slub.c:4569
 dev_uevent+0x32a/0x6f0 drivers/base/core.c:2324
 uevent_show+0x1a0/0x310 drivers/base/core.c:2403
 dev_attr_show+0x56/0xd0 drivers/base/core.c:2105
 sysfs_kf_seq_show+0x265/0x3e0 fs/sysfs/file.c:61
 kernfs_seq_show+0x119/0x160 fs/kernfs/file.c:168
 seq_read_iter+0x430/0xd00 fs/seq_file.c:230
 kernfs_fop_read_iter+0x145/0x470 fs/kernfs/file.c:241
 call_read_iter include/linux/fs.h:2196 [inline]
 new_sync_read fs/read_write.c:404 [inline]
 vfs_read+0xa7e/0xd40 fs/read_write.c:485
 ksys_read+0x199/0x2c0 fs/read_write.c:623
 __do_sys_read fs/read_write.c:633 [inline]
 __se_sys_read fs/read_write.c:631 [inline]
 __x64_sys_read+0x7b/0x90 fs/read_write.c:631
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f1e3d70bb6a
Code: 00 3d 00 00 41 00 75 0d 50 48 8d 3d 2d 08 0a 00 e8 ea 7d 01 00 31 c0 e9 07 ff ff ff 64 8b 04 25 18 00 00 00 85 c0 75 1b 0f 05 <48> 3d 00 f0 ff ff 76 6c 48 8b 15 8f a2 0d 00 f7 d8 64 89 02 48 83
RSP: 002b:00007ffddffe9558 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00005628af8fcf70 RCX: 00007f1e3d70bb6a
RDX: 0000000000001000 RSI: 00005628af9635e0 RDI: 000000000000000c
RBP: 00005628af8fcf70 R08: 000000000000000c R09: 0000000000000000
R10: 000000000000010f R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000003fff R14: 00007ffddffe9a38 R15: 000000000000000a
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 13750 Comm: syz-executor.3 Not tainted 5.15.149-syzkaller-00490-g5d96939590c0 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
RIP: 0010:native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
RIP: 0010:arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
RIP: 0010:kvm_wait+0x147/0x180 arch/x86/kernel/kvm.c:918
Code: 4c 89 e8 48 c1 e8 03 42 0f b6 04 20 84 c0 44 8b 74 24 1c 75 34 41 0f b6 45 00 44 38 f0 75 10 66 90 0f 00 2d 5b 03 f3 03 fb f4 <e9> 24 ff ff ff fb e9 1e ff ff ff 44 89 e9 80 e1 07 38 c1 7c a3 4c
RSP: 0018:ffffc90000b973a0 EFLAGS: 00000246
RAX: 0000000000000001 RBX: 1ffff92000172e78 RCX: 1ffffffff0d1aa9c
RDX: 0000000000000001 RSI: 0000000000000001 RDI: ffff8881f7137ed4
RBP: ffffc90000b97450 R08: dffffc0000000000 R09: ffffed103ee26fdb
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: ffff8881f7137ed4 R14: 0000000000000001 R15: 1ffff92000172e7c
FS:  00007f83f99726c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020001000 CR3: 0000000116a9d000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 pv_wait arch/x86/include/asm/paravirt.h:597 [inline]
 pv_wait_node kernel/locking/qspinlock_paravirt.h:325 [inline]
 __pv_queued_spin_lock_slowpath+0x41b/0xc40 kernel/locking/qspinlock.c:473
 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:585 [inline]
 queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline]
 queued_spin_lock include/asm-generic/qspinlock.h:85 [inline]
 do_raw_spin_lock include/linux/spinlock.h:187 [inline]
 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:136 [inline]
 _raw_spin_lock_bh+0x139/0x1b0 kernel/locking/spinlock.c:178
 sock_hash_delete_elem+0xb1/0x2f0 net/core/sock_map.c:937
 bpf_prog_2c29ac5cdc6b1842+0x3a/0xc20
 bpf_dispatcher_nop_func include/linux/bpf.h:785 [inline]
 __bpf_prog_run include/linux/filter.h:625 [inline]
 bpf_prog_run include/linux/filter.h:632 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:1883 [inline]
 bpf_trace_run2+0xec/0x210 kernel/trace/bpf_trace.c:1920
 __bpf_trace_kfree+0x6f/0x90 include/trace/events/kmem.h:118
 trace_kfree include/trace/events/kmem.h:118 [inline]
 kfree+0x1f3/0x220 mm/slub.c:4569
 p9_client_create+0x5c6/0x1130 net/9p/client.c:1023
 v9fs_session_init+0x1fa/0x19b0 fs/9p/v9fs.c:409
 v9fs_mount+0x75/0x7f0 fs/9p/vfs_super.c:126
 legacy_get_tree+0xf1/0x190 fs/fs_context.c:611
 vfs_get_tree+0x88/0x290 fs/super.c:1517
 do_new_mount+0x2ba/0xb30 fs/namespace.c:3005
 path_mount+0x671/0x1070 fs/namespace.c:3335
 do_mount fs/namespace.c:3348 [inline]
 __do_sys_mount fs/namespace.c:3556 [inline]
 __se_sys_mount+0x2c4/0x3b0 fs/namespace.c:3533
 __x64_sys_mount+0xbf/0xd0 fs/namespace.c:3533
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f83fabfeca9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f83f99720c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f83fad2cf80 RCX: 00007f83fabfeca9
RDX: 0000000020000200 RSI: 0000000020000000 RDI: 0000000000000000
RBP: 00007f83fac4a47e R08: 0000000020000600 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000004d R14: 00007f83fad2cf80 R15: 00007ffe384006f8
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/05/06 18:19 android13-5.15-lts 5d96939590c0 d884b519 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 BUG: soft lockup in kernfs_fop_read_iter
* Struck through repros no longer work on HEAD.