syzbot


general protection fault in __ext4_journal_get_write_access

Status: upstream: reported on 2024/09/12 07:30
Reported-by: syzbot+ce26a284328a0888f466@syzkaller.appspotmail.com
First crash: 70d, last: 67d
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream general protection fault in __ext4_journal_get_write_access fuse ext4 C done done 7 1472d 1521d 22/28 fixed on 2022/11/15 22:34
android-6-1 general protection fault in __ext4_journal_get_write_access origin:lts syz 62 3h04m 247d 0/2 premoderation: reported syz repro on 2024/03/19 01:39

Sample crash report:
loop0: detected capacity change from 0 to 128
EXT4-fs (loop0): mounted filesystem without journal. Quota mode: none.
general protection fault, probably for non-canonical address 0xdffffc0000000007: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000038-0x000000000000003f]
CPU: 0 PID: 4012 Comm: syz.0.68 Not tainted 6.1.110-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
RIP: 0010:__ext4_journal_get_write_access+0xc6/0x6b0 fs/ext4/ext4_jbd2.c:231
Code: 31 c0 49 8d 5e 30 48 89 d8 48 c1 e8 03 42 80 3c 28 00 74 08 48 89 df e8 18 a2 af ff 48 8b 1b 48 83 c3 38 48 89 d8 48 c1 e8 03 <42> 80 3c 28 00 74 08 48 89 df e8 fb a1 af ff 4c 8b 23 4d 85 e4 4c
RSP: 0018:ffffc900038ef800 EFLAGS: 00010202
RAX: 0000000000000007 RBX: 0000000000000038 RCX: ffff88802aab3b80
RDX: dffffc0000000000 RSI: ffff88802aab3b80 RDI: ffffc900038ef780
RBP: ffffc900038ef8d0 R08: ffff888075ff4910 R09: 0000000000000001
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff888077ff6678
R13: dffffc0000000000 R14: ffff888075ff4910 R15: 0000000000000001
FS:  00007f6a5e9d36c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fff852ad028 CR3: 000000005d6bc000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 ext4_update_primary_sb fs/ext4/ioctl.c:67 [inline]
 ext4_update_superblocks_fn+0x2f5/0x1020 fs/ext4/ioctl.c:221
 ext4_fill_super+0x3142/0x8b50 fs/ext4/super.c:5683
 get_tree_bdev+0x3fe/0x620 fs/super.c:1366
 vfs_get_tree+0x88/0x270 fs/super.c:1573
 do_new_mount+0x2ba/0xb40 fs/namespace.c:3051
 do_mount fs/namespace.c:3394 [inline]
 __do_sys_mount fs/namespace.c:3602 [inline]
 __se_sys_mount+0x2d5/0x3c0 fs/namespace.c:3579
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f6a5db7f69a
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f6a5e9d2e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f6a5e9d2ef0 RCX: 00007f6a5db7f69a
RDX: 0000000020000200 RSI: 0000000020000740 RDI: 00007f6a5e9d2eb0
RBP: 0000000020000200 R08: 00007f6a5e9d2ef0 R09: 000000000000c000
R10: 000000000000c000 R11: 0000000000000246 R12: 0000000020000740
R13: 00007f6a5e9d2eb0 R14: 0000000000000246 R15: 00000000200006c0
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__ext4_journal_get_write_access+0xc6/0x6b0 fs/ext4/ext4_jbd2.c:231
Code: 31 c0 49 8d 5e 30 48 89 d8 48 c1 e8 03 42 80 3c 28 00 74 08 48 89 df e8 18 a2 af ff 48 8b 1b 48 83 c3 38 48 89 d8 48 c1 e8 03 <42> 80 3c 28 00 74 08 48 89 df e8 fb a1 af ff 4c 8b 23 4d 85 e4 4c
RSP: 0018:ffffc900038ef800 EFLAGS: 00010202
RAX: 0000000000000007 RBX: 0000000000000038 RCX: ffff88802aab3b80
RDX: dffffc0000000000 RSI: ffff88802aab3b80 RDI: ffffc900038ef780
RBP: ffffc900038ef8d0 R08: ffff888075ff4910 R09: 0000000000000001
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff888077ff6678
R13: dffffc0000000000 R14: ffff888075ff4910 R15: 0000000000000001
FS:  00007f6a5e9d36c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f42e22e8108 CR3: 000000005d6bc000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	31 c0                	xor    %eax,%eax
   2:	49 8d 5e 30          	lea    0x30(%r14),%rbx
   6:	48 89 d8             	mov    %rbx,%rax
   9:	48 c1 e8 03          	shr    $0x3,%rax
   d:	42 80 3c 28 00       	cmpb   $0x0,(%rax,%r13,1)
  12:	74 08                	je     0x1c
  14:	48 89 df             	mov    %rbx,%rdi
  17:	e8 18 a2 af ff       	call   0xffafa234
  1c:	48 8b 1b             	mov    (%rbx),%rbx
  1f:	48 83 c3 38          	add    $0x38,%rbx
  23:	48 89 d8             	mov    %rbx,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 80 3c 28 00       	cmpb   $0x0,(%rax,%r13,1) <-- trapping instruction
  2f:	74 08                	je     0x39
  31:	48 89 df             	mov    %rbx,%rdi
  34:	e8 fb a1 af ff       	call   0xffafa234
  39:	4c 8b 23             	mov    (%rbx),%r12
  3c:	4d 85 e4             	test   %r12,%r12
  3f:	4c                   	rex.WR

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/09/15 15:33 linux-6.1.y 5f55cad62cc9 08d8a733 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan general protection fault in __ext4_journal_get_write_access
2024/09/12 07:29 linux-6.1.y 5ca5b389fddf d94c83d8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan general protection fault in __ext4_journal_get_write_access
* Struck through repros no longer work on HEAD.