syzbot


general protection fault in __writeback_single_inode

Status: auto-obsoleted due to no activity on 2024/01/12 03:35
Reported-by: syzbot+ecbbfd0f5c70f48472aa@syzkaller.appspotmail.com
First crash: 143d, last: 143d

Sample crash report:
general protection fault, probably for non-canonical address 0xdffffc0000000004: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000020-0x0000000000000027]
CPU: 0 PID: 32766 Comm: kworker/u4:2 Not tainted 5.10.194-syzkaller-00508-ga27512601c2d #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023
Workqueue: writeback wb_workfn (flush-7:1)
RIP: 0010:write_inode fs/fs-writeback.c:1327 [inline]
RIP: 0010:__writeback_single_inode+0x438/0xac0 fs/fs-writeback.c:1527
Code: 00 fc ff df 80 3c 08 00 74 08 48 89 df e8 80 18 eb ff 48 8b 1b 48 83 c3 20 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 48 89 df e8 5a 18 eb ff 48 83 3b 00 74 26 4c 89
RSP: 0018:ffffc90009c375b8 EFLAGS: 00010202
RAX: 0000000000000004 RBX: 0000000000000020 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90009c37610 R08: ffffffff81bcdbdc R09: 0000000000000003
R10: fffff52001386ea8 R11: dffffc0000000001 R12: 1ffff1102c6cedb3
R13: ffff888163676d70 R14: ffff888163676df8 R15: ffff888163676d98
FS:  0000000000000000(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f79d246bd00 CR3: 000000011ce48000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 writeback_sb_inodes+0x99c/0x16b0 fs/fs-writeback.c:1733
 __writeback_inodes_wb fs/fs-writeback.c:1804 [inline]
 wb_writeback+0x4b7/0xc60 fs/fs-writeback.c:1910
 wb_check_old_data_flush fs/fs-writeback.c:2012 [inline]
 wb_do_writeback fs/fs-writeback.c:2065 [inline]
 wb_workfn+0xb3d/0x1110 fs/fs-writeback.c:2094
 process_one_work+0x6dc/0xbd0 kernel/workqueue.c:2301
 worker_thread+0xaea/0x1510 kernel/workqueue.c:2447
 kthread+0x34b/0x3d0 kernel/kthread.c:313
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:299
Modules linked in:
---[ end trace eaf927b2005d7851 ]---
RIP: 0010:write_inode fs/fs-writeback.c:1327 [inline]
RIP: 0010:__writeback_single_inode+0x438/0xac0 fs/fs-writeback.c:1527
Code: 00 fc ff df 80 3c 08 00 74 08 48 89 df e8 80 18 eb ff 48 8b 1b 48 83 c3 20 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 48 89 df e8 5a 18 eb ff 48 83 3b 00 74 26 4c 89
RSP: 0018:ffffc90009c375b8 EFLAGS: 00010202
RAX: 0000000000000004 RBX: 0000000000000020 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90009c37610 R08: ffffffff81bcdbdc R09: 0000000000000003
R10: fffff52001386ea8 R11: dffffc0000000001 R12: 1ffff1102c6cedb3
R13: ffff888163676d70 R14: ffff888163676df8 R15: ffff888163676d98
FS:  0000000000000000(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe1838f2988 CR3: 00000001578d0000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess), 4 bytes skipped:
   0:	80 3c 08 00          	cmpb   $0x0,(%rax,%rcx,1)
   4:	74 08                	je     0xe
   6:	48 89 df             	mov    %rbx,%rdi
   9:	e8 80 18 eb ff       	call   0xffeb188e
   e:	48 8b 1b             	mov    (%rbx),%rbx
  11:	48 83 c3 20          	add    $0x20,%rbx
  15:	48 89 d8             	mov    %rbx,%rax
  18:	48 c1 e8 03          	shr    $0x3,%rax
  1c:	48 b9 00 00 00 00 00 	movabs $0xdffffc0000000000,%rcx
  23:	fc ff df
* 26:	80 3c 08 00          	cmpb   $0x0,(%rax,%rcx,1) <-- trapping instruction
  2a:	74 08                	je     0x34
  2c:	48 89 df             	mov    %rbx,%rdi
  2f:	e8 5a 18 eb ff       	call   0xffeb188e
  34:	48 83 3b 00          	cmpq   $0x0,(%rbx)
  38:	74 26                	je     0x60
  3a:	4c                   	rex.WR
  3b:	89                   	.byte 0x89

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/10/14 03:31 android13-5.10-lts a27512601c2d f757a323 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in __writeback_single_inode
* Struck through repros no longer work on HEAD.