syzbot
general protection fault in path_put
Status:
upstream: reported C repro on 2026/07/31 17:14
Subsystems:
fs
Labels:
prio:low
[Documentation on labels]
Reported-by: syzbot+1686d17ae576cc5f8a57@syzkaller.appspotmail.com
First crash: 2d21h, last: 1h00m
Sample crash report:
RBP: 00007fffaa9085c0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007feae0225fac R14: 00007feae0225fa0 R15: 00007feae0225fa0
</TASK>
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000008: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000040-0x0000000000000047]
CPU: 0 UID: 0 PID: 5912 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:path_put+0x22/0x70 fs/namei.c:722
Code: 90 90 90 90 90 90 90 90 f3 0f 1e fa 53 48 89 fb e8 a3 61 78 ff 48 8d 7b 08 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 75 29 48 8b 7b 08 e8 4f 97 04 00 48 89 da 48 b8 00 00
RSP: 0018:ffffc900040c7a68 EFLAGS: 00010203
RAX: dffffc0000000000 RBX: 000000000000003c RCX: 0000000000000000
RDX: 0000000000000008 RSI: ffffffff8291fe9d RDI: 0000000000000044
RBP: ffffc900040c7bf8 R08: 0000000000000001 R09: 0000000000000000
R10: ffffffff9b74bc40 R11: 0000000000000000 R12: ffff888022ab1f88
R13: ffff88802dcb4a60 R14: ffff888022a9c680 R15: fffffffffffffff4
FS: 000055557d29f500(0000) GS:ffff8880d5ddc000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b32f63fff CR3: 000000003cf56000 CR4: 0000000000352ef0
Call Trace:
<TASK>
free_trace_uprobe kernel/trace/trace_uprobe.c:374 [inline]
free_trace_uprobe kernel/trace/trace_uprobe.c:369 [inline]
__free_free_trace_uprobe kernel/trace/trace_uprobe.c:536 [inline]
__trace_uprobe_create+0x96d/0x22f0 kernel/trace/trace_uprobe.c:545
trace_probe_create+0xef/0x100 kernel/trace/trace_probe.c:2371
dyn_event_create+0x46/0x70 kernel/trace/trace_dynevent.c:128
create_or_delete_trace_uprobe+0x5a/0xb0 kernel/trace/trace_uprobe.c:739
trace_parse_run_command+0x1ab/0x3b0 kernel/trace/trace.c:9565
vfs_write+0x2aa/0x1050 fs/read_write.c:685
ksys_write+0x12a/0x250 fs/read_write.c:739
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7feadff9df99
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fffaa908558 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007feae0225fa0 RCX: 00007feadff9df99
RDX: 000000000000000f RSI: 0000200000000180 RDI: 0000000000000004
RBP: 00007fffaa9085c0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007feae0225fac R14: 00007feae0225fa0 R15: 00007feae0225fa0
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:path_put+0x22/0x70 fs/namei.c:722
Code: 90 90 90 90 90 90 90 90 f3 0f 1e fa 53 48 89 fb e8 a3 61 78 ff 48 8d 7b 08 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 75 29 48 8b 7b 08 e8 4f 97 04 00 48 89 da 48 b8 00 00
RSP: 0018:ffffc900040c7a68 EFLAGS: 00010203
RAX: dffffc0000000000 RBX: 000000000000003c RCX: 0000000000000000
RDX: 0000000000000008 RSI: ffffffff8291fe9d RDI: 0000000000000044
RBP: ffffc900040c7bf8 R08: 0000000000000001 R09: 0000000000000000
R10: ffffffff9b74bc40 R11: 0000000000000000 R12: ffff888022ab1f88
R13: ffff88802dcb4a60 R14: ffff888022a9c680 R15: fffffffffffffff4
FS: 000055557d29f500(0000) GS:ffff8880d5edc000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b32f24008 CR3: 000000003cf56000 CR4: 0000000000352ef0
----------------
Code disassembly (best guess):
0: 90 nop
1: 90 nop
2: 90 nop
3: 90 nop
4: 90 nop
5: 90 nop
6: 90 nop
7: 90 nop
8: f3 0f 1e fa endbr64
c: 53 push %rbx
d: 48 89 fb mov %rdi,%rbx
10: e8 a3 61 78 ff call 0xff7861b8
15: 48 8d 7b 08 lea 0x8(%rbx),%rdi
19: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
20: fc ff df
23: 48 89 fa mov %rdi,%rdx
26: 48 c1 ea 03 shr $0x3,%rdx
* 2a: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) <-- trapping instruction
2e: 75 29 jne 0x59
30: 48 8b 7b 08 mov 0x8(%rbx),%rdi
34: e8 4f 97 04 00 call 0x49788
39: 48 89 da mov %rbx,%rdx
3c: 48 rex.W
3d: b8 .byte 0xb8
Struck through repros no longer work on HEAD.