syzbot


general protection fault in call_timer_fn (2)

Status: moderation: reported on 2025/09/01 08:48
Subsystems: kernfs
[Documentation on labels]
Reported-by: syzbot+1626cfcca8e02b21afa7@syzkaller.appspotmail.com
First crash: 5d03h, last: 5d03h
Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream general protection fault in call_timer_fn mm rdma acpi 2 3 207d 318d 0/29 auto-obsoleted due to no activity on 2025/05/07 21:33
android-54 BUG: unable to handle kernel NULL pointer dereference in call_timer_fn (3) 10 C 1132 98d 158d 0/2 upstream: reported C repro on 2025/03/27 18:17
android-54 BUG: unable to handle kernel NULL pointer dereference in call_timer_fn (2) 10 370 426d 1236d 0/2 auto-obsoleted due to no activity on 2024/09/11 07:53

Sample crash report:
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000006: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000030-0x0000000000000037]
CPU: 1 UID: 0 PID: 6784 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:trace_event_get_offsets_lock_acquire include/trace/events/lock.h:24 [inline]
RIP: 0010:do_perf_trace_lock_acquire include/trace/events/lock.h:24 [inline]
RIP: 0010:perf_trace_lock_acquire+0xa1/0x410 include/trace/events/lock.h:24
Code: 3c 08 04 f3 f3 f3 48 c7 44 24 60 00 00 00 00 c7 84 24 80 00 00 00 00 00 00 00 48 89 74 24 30 48 8d 5e 18 48 89 d8 48 c1 e8 03 <42> 80 3c 38 00 74 08 48 89 df e8 70 7c 86 00 48 8b 03 48 85 c0 48
RSP: 0018:ffffc90000a08940 EFLAGS: 00010006
RAX: 0000000000000006 RBX: 0000000000000030 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000018 RDI: ffffffff8e008e60
RBP: ffffc90000a08a40 R08: 0000000000000000 R09: 0000000000000001
R10: dffffc0000000000 R11: ffffed10044f692f R12: 1ffff92000141130
R13: 0000000000000018 R14: ffffffff8e008e60 R15: dffffc0000000000
FS:  0000555585eed500(0000) GS:ffff888125d1c000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055555f2285c8 CR3: 0000000026022000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 __do_trace_lock_acquire include/trace/events/lock.h:24 [inline]
 trace_lock_acquire include/trace/events/lock.h:24 [inline]
 lock_acquire+0x311/0x360 kernel/locking/lockdep.c:5831
 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
 _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
 __queue_work+0x809/0xfb0 kernel/workqueue.c:-1
 call_timer_fn+0x17b/0x5f0 kernel/time/timer.c:1747
 expire_timers kernel/time/timer.c:1793 [inline]
 __run_timers kernel/time/timer.c:2372 [inline]
 __run_timer_base+0x646/0x860 kernel/time/timer.c:2384
 run_timer_base kernel/time/timer.c:2393 [inline]
 run_timer_softirq+0xb7/0x180 kernel/time/timer.c:2403
 handle_softirqs+0x283/0x870 kernel/softirq.c:579
 __do_softirq kernel/softirq.c:613 [inline]
 invoke_softirq kernel/softirq.c:453 [inline]
 __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1050
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_is_held_type+0x137/0x190 kernel/locking/lockdep.c:5945
Code: 01 75 44 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 75 4c 41 f7 c4 00 02 00 00 74 01 fb 65 48 8b 05 f9 03 27 07 <48> 3b 44 24 08 75 43 89 d8 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f
RSP: 0018:ffffc9001d826770 EFLAGS: 00000206
RAX: b973a21ede490300 RBX: 0000000000000001 RCX: b973a21ede490300
RDX: 0000000000000003 RSI: ffffffff8dba5ce5 RDI: ffffffff8be33300
RBP: 00000000ffffffff R08: 0000000000000000 R09: ffffffff825d3aac
R10: dffffc0000000000 R11: ffffed100365ff25 R12: 0000000000000246
R13: ffff88807bd43c00 R14: ffff88801b2ff988 R15: 0000000000000002
 lock_is_held include/linux/lockdep.h:249 [inline]
 kernfs_root_is_locked fs/kernfs/kernfs-internal.h:109 [inline]
 kernfs_rcu_name fs/kernfs/kernfs-internal.h:119 [inline]
 kernfs_sd_compare fs/kernfs/dir.c:349 [inline]
 kernfs_link_sibling+0xf7/0x3e0 fs/kernfs/dir.c:380
 kernfs_add_one+0x1e0/0x520 fs/kernfs/dir.c:810
 __kernfs_create_file+0x22b/0x2e0 fs/kernfs/file.c:1068
 sysfs_add_file_mode_ns+0x238/0x300 fs/sysfs/file.c:319
 create_files fs/sysfs/group.c:76 [inline]
 internal_create_group+0x66d/0x1110 fs/sysfs/group.c:183
 internal_create_groups fs/sysfs/group.c:223 [inline]
 sysfs_create_groups+0x59/0x120 fs/sysfs/group.c:249
 device_add_groups drivers/base/core.c:2836 [inline]
 device_add_attrs+0xe0/0x5a0 drivers/base/core.c:2900
 device_add+0x496/0xb50 drivers/base/core.c:3643
 netdev_register_kobject+0x178/0x310 net/core/net-sysfs.c:2356
 register_netdevice+0x126c/0x1ae0 net/core/dev.c:11189
 veth_newlink+0x5cc/0xa50 drivers/net/veth.c:1884
 rtnl_newlink_create+0x30d/0xb00 net/core/rtnetlink.c:3825
 __rtnl_newlink net/core/rtnetlink.c:3942 [inline]
 rtnl_newlink+0x16d6/0x1c70 net/core/rtnetlink.c:4057
 rtnetlink_rcv_msg+0x7cc/0xb70 net/core/rtnetlink.c:6946
 netlink_rcv_skb+0x205/0x470 net/netlink/af_netlink.c:2552
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x82c/0x9e0 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896
 sock_sendmsg_nosec net/socket.c:714 [inline]
 __sock_sendmsg+0x21c/0x270 net/socket.c:729
 __sys_sendto+0x3bd/0x520 net/socket.c:2228
 __do_sys_sendto net/socket.c:2235 [inline]
 __se_sys_sendto net/socket.c:2231 [inline]
 __x64_sys_sendto+0xde/0x100 net/socket.c:2231
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7d15f90a7c
Code: 2a 5f 02 00 44 8b 4c 24 2c 4c 8b 44 24 20 89 c5 44 8b 54 24 28 48 8b 54 24 18 b8 2c 00 00 00 48 8b 74 24 10 8b 7c 24 08 0f 05 <48> 3d 00 f0 ff ff 77 34 89 ef 48 89 44 24 08 e8 70 5f 02 00 48 8b
RSP: 002b:00007ffdb7942f30 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f7d16ce4620 RCX: 00007f7d15f90a7c
RDX: 000000000000002c RSI: 00007f7d16ce4670 RDI: 0000000000000003
RBP: 0000000000000000 R08: 00007ffdb7942f84 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003
R13: 0000000000000000 R14: 00007f7d16ce4670 R15: 0000000000000000
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:trace_event_get_offsets_lock_acquire include/trace/events/lock.h:24 [inline]
RIP: 0010:do_perf_trace_lock_acquire include/trace/events/lock.h:24 [inline]
RIP: 0010:perf_trace_lock_acquire+0xa1/0x410 include/trace/events/lock.h:24
Code: 3c 08 04 f3 f3 f3 48 c7 44 24 60 00 00 00 00 c7 84 24 80 00 00 00 00 00 00 00 48 89 74 24 30 48 8d 5e 18 48 89 d8 48 c1 e8 03 <42> 80 3c 38 00 74 08 48 89 df e8 70 7c 86 00 48 8b 03 48 85 c0 48
RSP: 0018:ffffc90000a08940 EFLAGS: 00010006
RAX: 0000000000000006 RBX: 0000000000000030 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000018 RDI: ffffffff8e008e60
RBP: ffffc90000a08a40 R08: 0000000000000000 R09: 0000000000000001
R10: dffffc0000000000 R11: ffffed10044f692f R12: 1ffff92000141130
R13: 0000000000000018 R14: ffffffff8e008e60 R15: dffffc0000000000
FS:  0000555585eed500(0000) GS:ffff888125d1c000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055555f2285c8 CR3: 0000000026022000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
----------------
Code disassembly (best guess):
   0:	3c 08                	cmp    $0x8,%al
   2:	04 f3                	add    $0xf3,%al
   4:	f3 f3 48 c7 44 24 60 	repz xrelease movq $0x0,0x60(%rsp)
   b:	00 00 00 00
   f:	c7 84 24 80 00 00 00 	movl   $0x0,0x80(%rsp)
  16:	00 00 00 00
  1a:	48 89 74 24 30       	mov    %rsi,0x30(%rsp)
  1f:	48 8d 5e 18          	lea    0x18(%rsi),%rbx
  23:	48 89 d8             	mov    %rbx,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 80 3c 38 00       	cmpb   $0x0,(%rax,%r15,1) <-- trapping instruction
  2f:	74 08                	je     0x39
  31:	48 89 df             	mov    %rbx,%rdi
  34:	e8 70 7c 86 00       	call   0x867ca9
  39:	48 8b 03             	mov    (%rbx),%rax
  3c:	48 85 c0             	test   %rax,%rax
  3f:	48                   	rex.W

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/08/28 08:37 bpf-next d3abefe89740 e12e5ba4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-bpf-next-kasan-gce general protection fault in call_timer_fn
* Struck through repros no longer work on HEAD.