[syzbot] [jfs?] general protection fault in lbmStartIO

From: syzbot
Date: Sat Oct 07 2023 - 18:25:06 EST


Hello,

syzbot found the following issue on:

HEAD commit: c9f2baaa18b5 Add linux-next specific files for 20231003
git tree: linux-next
console+strace: https://syzkaller.appspot.com/x/log.txt?x=1319f981680000
kernel config: https://syzkaller.appspot.com/x/.config?x=3fe9c462fee1649f
dashboard link: https://syzkaller.appspot.com/bug?extid=23bc20037854bb335d59
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=16204836680000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=12b62ee6680000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/5361e41384fe/disk-c9f2baaa.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/7028b209124d/vmlinux-c9f2baaa.xz
kernel image: https://storage.googleapis.com/syzbot-assets/a167dc667ee5/bzImage-c9f2baaa.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/ef5dd9fc6a1b/mount_0.gz

The issue was bisected to:

commit bacfceeda53ea9ee9af714245e6c67aa70632b63
Author: Jan Kara <jack@xxxxxxx>
Date: Wed Sep 27 09:34:30 2023 +0000

jfs: Convert to bdev_open_by_dev()

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=13a06d8a680000
final oops: https://syzkaller.appspot.com/x/report.txt?x=10606d8a680000
console output: https://syzkaller.appspot.com/x/log.txt?x=17a06d8a680000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+23bc20037854bb335d59@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: bacfceeda53e ("jfs: Convert to bdev_open_by_dev()")

general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 1 PID: 5058 Comm: syz-executor352 Not tainted 6.6.0-rc4-next-20231003-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023
RIP: 0010:lbmStartIO+0xb7/0x3a0 fs/jfs/jfs_logmgr.c:2116
Code: fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 cf 02 00 00 48 b8 00 00 00 00 00 fc ff df 49 8b 5c 24 20 48 89 da 48 c1 ea 03 <80> 3c 02 00 0f 85 86 02 00 00 48 8b 3b ba 01 08 00 00 b9 40 0c 00
RSP: 0018:ffffc90003a5fa90 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff82fd8ed3
RDX: 0000000000000000 RSI: ffffffff82fd8ee1 RDI: ffff88807bb07020
RBP: ffff88801764d800 R08: 0000000000000005 R09: 0000000000000003
R10: 0000000000000002 R11: ffffffff910eb4a0 R12: ffff88807bb07000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000002
FS: 0000555555ed5380(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fffc6e0506c CR3: 000000007c5c6000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
lbmWrite+0x32e/0x470 fs/jfs/jfs_logmgr.c:2067
lmNextPage.isra.0+0x278/0x700 fs/jfs/jfs_logmgr.c:616
lmWriteRecord+0xb6d/0x12a0 fs/jfs/jfs_logmgr.c:529
lmLogSync+0x182/0x820 fs/jfs/jfs_logmgr.c:969
jfs_syncpt+0x89/0xa0 fs/jfs/jfs_logmgr.c:1041
jfs_sync_fs+0x83/0xa0 fs/jfs/super.c:685
sync_filesystem fs/sync.c:56 [inline]
sync_filesystem+0x109/0x280 fs/sync.c:30
generic_shutdown_super+0x7e/0x3c0 fs/super.c:669
kill_block_super+0x3b/0x90 fs/super.c:1652
deactivate_locked_super+0xbc/0x1a0 fs/super.c:484
deactivate_super+0xde/0x100 fs/super.c:517
cleanup_mnt+0x222/0x3d0 fs/namespace.c:1256
task_work_run+0x14d/0x240 kernel/task_work.c:180
ptrace_notify+0x10c/0x130 kernel/signal.c:2399
ptrace_report_syscall include/linux/ptrace.h:411 [inline]
ptrace_report_syscall_exit include/linux/ptrace.h:473 [inline]
syscall_exit_work kernel/entry/common.c:251 [inline]
syscall_exit_to_user_mode_prepare+0x120/0x220 kernel/entry/common.c:278
__syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline]
syscall_exit_to_user_mode+0xd/0x60 kernel/entry/common.c:296
do_syscall_64+0x44/0xb0 arch/x86/entry/common.c:87
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7ff1e4cd5547
Code: 07 00 48 83 c4 08 5b 5d c3 66 2e 0f 1f 84 00 00 00 00 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 b8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007fffc6e05058 EFLAGS: 00000202 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007ff1e4cd5547
RDX: 0000000000000000 RSI: 000000000000000a RDI: 00007fffc6e05110
RBP: 00007fffc6e05110 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000202 R12: 00007fffc6e06180
R13: 0000555555ed66c0 R14: 431bde82d7b634db R15: 00007fffc6e061a0
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:lbmStartIO+0xb7/0x3a0 fs/jfs/jfs_logmgr.c:2116
Code: fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 cf 02 00 00 48 b8 00 00 00 00 00 fc ff df 49 8b 5c 24 20 48 89 da 48 c1 ea 03 <80> 3c 02 00 0f 85 86 02 00 00 48 8b 3b ba 01 08 00 00 b9 40 0c 00
RSP: 0018:ffffc90003a5fa90 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff82fd8ed3
RDX: 0000000000000000 RSI: ffffffff82fd8ee1 RDI: ffff88807bb07020
RBP: ffff88801764d800 R08: 0000000000000005 R09: 0000000000000003
R10: 0000000000000002 R11: ffffffff910eb4a0 R12: ffff88807bb07000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000002
FS: 0000555555ed5380(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555555ede6f8 CR3: 000000007c5c6000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess), 2 bytes skipped:
0: df 48 89 fisttps -0x77(%rax)
3: fa cli
4: 48 c1 ea 03 shr $0x3,%rdx
8: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1)
c: 0f 85 cf 02 00 00 jne 0x2e1
12: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
19: fc ff df
1c: 49 8b 5c 24 20 mov 0x20(%r12),%rbx
21: 48 89 da mov %rbx,%rdx
24: 48 c1 ea 03 shr $0x3,%rdx
* 28: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) <-- trapping instruction
2c: 0f 85 86 02 00 00 jne 0x2b8
32: 48 8b 3b mov (%rbx),%rdi
35: ba 01 08 00 00 mov $0x801,%edx
3a: b9 .byte 0xb9
3b: 40 0c 00 rex or $0x0,%al


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