syzbot


general protection fault in mnt_want_write

Status: premoderation: reported on 2024/04/10 13:00
Reported-by: syzbot+31a28b263c400e089e3c@syzkaller.appspotmail.com
First crash: 63d, last: 63d
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-5-10 general protection fault in mnt_want_write (2) 1 118d 118d 0/2 auto-obsoleted due to no activity on 2024/05/15 10:15
android-5-10 general protection fault in mnt_want_write 1 811d 811d 0/2 auto-closed as invalid on 2022/06/22 11:51

Sample crash report:
incfs: ino conflict with backing FS 2
incfs: ino conflict with backing FS 5
general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
CPU: 1 PID: 10050 Comm: syz-executor.3 Tainted: G        W          6.1.75-syzkaller-00012-g5dc2bc296647 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
RIP: 0010:mnt_want_write+0x32/0x300 fs/namespace.c:393
Code: 41 55 41 54 53 48 83 ec 18 48 89 fb 49 be 00 00 00 00 00 fc ff df e8 3d fc a7 ff 48 89 5d d0 48 83 c3 08 49 89 dc 49 c1 ec 03 <43> 80 3c 34 00 74 08 48 89 df e8 ef dc ee ff 48 89 5d c0 4c 8b 2b
RSP: 0018:ffffc90002fcfa20 EFLAGS: 00010202
RAX: ffffffff81cd61e3 RBX: 0000000000000008 RCX: 0000000000040000
RDX: ffffc90016af9000 RSI: 00000000000006f7 RDI: 00000000000006f8
RBP: ffffc90002fcfa60 R08: ffffffff821ee016 R09: 0000000000000003
R10: ffffffffffffffff R11: dffffc0000000001 R12: 0000000000000001
R13: 1ffff1102bbb100d R14: dffffc0000000000 R15: dffffc0000000000
FS:  00007fa010b7f6c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555555f84858 CR3: 000000016dce2000 CR4: 00000000003506a0
Call Trace:
 <TASK>
 ovl_want_write+0x91/0xa0 fs/overlayfs/util.c:22
 ovl_setattr+0xb0/0x560 fs/overlayfs/inode.c:33
 notify_change+0xd53/0x1010 fs/attr.c:499
 incfs_setattr+0x1ff/0x3f0 fs/incfs/vfs.c:1653
 notify_change+0xd53/0x1010 fs/attr.c:499
 chown_common+0x570/0x8b0 fs/open.c:737
 do_fchownat+0x169/0x240 fs/open.c:768
 __do_sys_chown fs/open.c:788 [inline]
 __se_sys_chown fs/open.c:786 [inline]
 __x64_sys_chown+0x82/0x90 fs/open.c:786
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fa00fe7de69
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:00007fa010b7f0c8 EFLAGS: 00000246 ORIG_RAX: 000000000000005c
RAX: ffffffffffffffda RBX: 00007fa00ffabf80 RCX: 00007fa00fe7de69
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000200
RBP: 00007fa00feca47a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007fa00ffabf80 R15: 00007ffde0c58378
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:mnt_want_write+0x32/0x300 fs/namespace.c:393
Code: 41 55 41 54 53 48 83 ec 18 48 89 fb 49 be 00 00 00 00 00 fc ff df e8 3d fc a7 ff 48 89 5d d0 48 83 c3 08 49 89 dc 49 c1 ec 03 <43> 80 3c 34 00 74 08 48 89 df e8 ef dc ee ff 48 89 5d c0 4c 8b 2b
RSP: 0018:ffffc90002fcfa20 EFLAGS: 00010202
RAX: ffffffff81cd61e3 RBX: 0000000000000008 RCX: 0000000000040000
RDX: ffffc90016af9000 RSI: 00000000000006f7 RDI: 00000000000006f8
RBP: ffffc90002fcfa60 R08: ffffffff821ee016 R09: 0000000000000003
R10: ffffffffffffffff R11: dffffc0000000001 R12: 0000000000000001
R13: 1ffff1102bbb100d R14: dffffc0000000000 R15: dffffc0000000000
FS:  00007fa010b7f6c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc5bdd025a0 CR3: 000000016dce2000 CR4: 00000000003506b0
----------------
Code disassembly (best guess):
   0:	41 55                	push   %r13
   2:	41 54                	push   %r12
   4:	53                   	push   %rbx
   5:	48 83 ec 18          	sub    $0x18,%rsp
   9:	48 89 fb             	mov    %rdi,%rbx
   c:	49 be 00 00 00 00 00 	movabs $0xdffffc0000000000,%r14
  13:	fc ff df
  16:	e8 3d fc a7 ff       	call   0xffa7fc58
  1b:	48 89 5d d0          	mov    %rbx,-0x30(%rbp)
  1f:	48 83 c3 08          	add    $0x8,%rbx
  23:	49 89 dc             	mov    %rbx,%r12
  26:	49 c1 ec 03          	shr    $0x3,%r12
* 2a:	43 80 3c 34 00       	cmpb   $0x0,(%r12,%r14,1) <-- trapping instruction
  2f:	74 08                	je     0x39
  31:	48 89 df             	mov    %rbx,%rdi
  34:	e8 ef dc ee ff       	call   0xffeedd28
  39:	48 89 5d c0          	mov    %rbx,-0x40(%rbp)
  3d:	4c 8b 2b             	mov    (%rbx),%r13

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/04/10 12:59 android14-6.1 5dc2bc296647 4320ec32 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-1 general protection fault in mnt_want_write
* Struck through repros no longer work on HEAD.