syzbot


general protection fault in do_rmdir

Status: premoderation: reported C repro on 2025/07/16 06:08
Bug presence: origin:downstream
[Documentation on labels]
Reported-by: syzbot+2d8d7a36d69a7f5cb038@syzkaller.appspotmail.com
First crash: 11d, last: 10d
Bug presence (3)
Date Name Commit Repro Result
2025/07/17 android16-6.12 (ToT) da324a107472 C [report] general protection fault in do_rmdir
2025/07/17 lts (merge base) e0e2f7824338 C Didn't crash
2025/07/17 upstream (ToT) e2291551827f C Didn't crash
Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-5-10 general protection fault in do_rmdir 2 C 18 17d 596d 0/2 upstream: reported C repro on 2023/12/08 13:26
android-5-15 general protection fault in do_rmdir origin:downstream 2 C 5 4h33m 596d 0/2 upstream: reported C repro on 2023/12/08 13:26
android-6-1 general protection fault in do_rmdir origin:downstream 2 C done 3 16d 596d 0/2 upstream: reported C repro on 2023/12/08 13:26

Sample crash report:
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000008: 0000 [#1] PREEMPT SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000040-0x0000000000000047]
CPU: 0 UID: 0 PID: 296 Comm: syz-executor282 Not tainted 6.12.30-syzkaller-g603af016e4a8 #0 c515e79d845c5a778cd5838f9063bc4edcb1333e
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:do_rmdir+0x1e8/0x560 fs/namei.c:4392
Code: 01 f0 ff ff 72 0a e8 a7 a8 9b ff e9 b9 00 00 00 4c 89 64 24 18 49 83 c4 30 4c 89 e0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 4c 89 e7 e8 5a a3 f1 ff 49 83 3c 24 00 74 75 e8
RSP: 0018:ffffc9000126fe20 EFLAGS: 00010203
RAX: 0000000000000008 RBX: ffff888103bc9100 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000000003 RDI: ffff888111075f60
RBP: ffffc9000126fef8 R08: ffff8881f6e509c7 R09: 1ffff1103edca138
R10: dffffc0000000000 R11: ffffed103edca139 R12: 0000000000000046
R13: 1ffff9200024dfcc R14: ffffc9000126fe80 R15: 00000000ffffff9c
FS:  00007ff4762bd6c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000001948 CR3: 0000000102b4a000 CR4: 00000000003526b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __do_sys_rmdir fs/namei.c:4418 [inline]
 __se_sys_rmdir fs/namei.c:4416 [inline]
 __x64_sys_rmdir+0x4b/0x60 fs/namei.c:4416
 x64_sys_call+0xaf7/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:85
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x58/0xf0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7ff47630f4f9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 c1 17 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:00007ff4762bd218 EFLAGS: 00000246 ORIG_RAX: 0000000000000054
RAX: ffffffffffffffda RBX: 00007ff47639c3e8 RCX: 00007ff47630f4f9
RDX: 00007ff47630f4f9 RSI: 0000000000000000 RDI: 0000200000000040
RBP: 00007ff47639c3e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ff476369034
R13: 000020000000c280 R14: 00007ff47636700e R15: 0000200000000000
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:do_rmdir+0x1e8/0x560 fs/namei.c:4392
Code: 01 f0 ff ff 72 0a e8 a7 a8 9b ff e9 b9 00 00 00 4c 89 64 24 18 49 83 c4 30 4c 89 e0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 4c 89 e7 e8 5a a3 f1 ff 49 83 3c 24 00 74 75 e8
RSP: 0018:ffffc9000126fe20 EFLAGS: 00010203

RAX: 0000000000000008 RBX: ffff888103bc9100 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000000003 RDI: ffff888111075f60
RBP: ffffc9000126fef8 R08: ffff8881f6e509c7 R09: 1ffff1103edca138
R10: dffffc0000000000 R11: ffffed103edca139 R12: 0000000000000046
R13: 1ffff9200024dfcc R14: ffffc9000126fe80 R15: 00000000ffffff9c
FS:  00007ff4762bd6c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000001948 CR3: 0000000102b4a000 CR4: 00000000003526b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess), 1 bytes skipped:
   0:	f0 ff                	lock (bad)
   2:	ff 72 0a             	push   0xa(%rdx)
   5:	e8 a7 a8 9b ff       	call   0xff9ba8b1
   a:	e9 b9 00 00 00       	jmp    0xc8
   f:	4c 89 64 24 18       	mov    %r12,0x18(%rsp)
  14:	49 83 c4 30          	add    $0x30,%r12
  18:	4c 89 e0             	mov    %r12,%rax
  1b:	48 c1 e8 03          	shr    $0x3,%rax
  1f:	48 b9 00 00 00 00 00 	movabs $0xdffffc0000000000,%rcx
  26:	fc ff df
* 29:	80 3c 08 00          	cmpb   $0x0,(%rax,%rcx,1) <-- trapping instruction
  2d:	74 08                	je     0x37
  2f:	4c 89 e7             	mov    %r12,%rdi
  32:	e8 5a a3 f1 ff       	call   0xfff1a391
  37:	49 83 3c 24 00       	cmpq   $0x0,(%r12)
  3c:	74 75                	je     0xb3
  3e:	e8                   	.byte 0xe8

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/07/16 06:56 android16-6.12 603af016e4a8 03fcfc4b .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust general protection fault in do_rmdir
2025/07/16 06:07 android16-6.12 603af016e4a8 03fcfc4b .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust general protection fault in do_rmdir
* Struck through repros no longer work on HEAD.