bisecting fixing commit since 7d120bf21c05cbe30a679f0feeca884eeaceb069
building syzkaller on 64ca0a371100fc7dfdb20de9263763e46c88a436
testing commit 7d120bf21c05cbe30a679f0feeca884eeaceb069 with gcc (GCC) 8.1.0
kernel signature: abb3399a5410d58d689173c5545653e5273956f099ef38272ac680c28fd7d0ce
all runs: crashed: kernel BUG at fs/buffer.c:LINE!
testing current HEAD 4fccc2503536a564a4ba31a1d50439854201659f
testing commit 4fccc2503536a564a4ba31a1d50439854201659f with gcc (GCC) 8.1.0
kernel signature: 94bd2345df71b1703e59fdffa41c2043c0ed7641630c48e7dc1e4263c44711a0
all runs: crashed: kernel BUG at fs/buffer.c:LINE!
revisions tested: 2, total time: 26m56.773796032s (build: 18m31.759964754s, test: 7m39.418993469s)
the crash still happens on HEAD
commit msg: Linux 4.19.105
crash: kernel BUG at fs/buffer.c:LINE!
------------[ cut here ]------------
kernel BUG at fs/buffer.c:3054!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 7284 Comm: syz-executor.0 Not tainted 4.19.105-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:submit_bh_wbc+0x4ee/0x700 fs/buffer.c:3054
Code: 33 45 89 65 10 4c 89 ef e8 3f e2 6c 01 31 c0 48 83 c4 20 5b 41 5c 41 5d 41 5e 41 5f 5d c3 f0 80 63 01 f7 e9 b8 fb ff ff 0f 0b <0f> 0b 0f 0b 0f 0b 0f 0b 0f 0b e8 73 ed ea ff eb c6 e8 cc ec ea ff
RSP: 0018:ffff888094197c60 EFLAGS: 00010246
RAX: 0000000000000005 RBX: ffff888087282150 RCX: 0000000000000000
RDX: 1ffff11010e5042a RSI: 0000000000000800 RDI: 0000000000000001
RBP: ffff888094197ca8 R08: 0000000000000000 R09: ffffed1010e50436
R10: ffffed1010e50436 R11: ffff8880872821b3 R12: 0000000000000800
R13: 0000000000000800 R14: 0000000000000000 R15: 0000000000000000
FS:  00000000011f3940(0000) GS:ffff8880aea00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000143b978 CR3: 000000007e5de000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 submit_bh fs/buffer.c:3101 [inline]
 __sync_dirty_buffer+0xcd/0x230 fs/buffer.c:3187
 sync_dirty_buffer+0xe/0x10 fs/buffer.c:3200
 fat_set_state+0x1be/0x280 fs/fat/inode.c:702
 fat_put_super+0x40/0xd0 fs/fat/inode.c:728
 generic_shutdown_super+0x12d/0x330 fs/super.c:456
 kill_block_super+0x96/0xe0 fs/super.c:1185
 deactivate_locked_super+0x77/0xd0 fs/super.c:329
 deactivate_super+0x136/0x150 fs/super.c:360
 cleanup_mnt+0xa3/0x130 fs/namespace.c:1098
 __cleanup_mnt+0xd/0x10 fs/namespace.c:1105
 task_work_run+0x108/0x180 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:193 [inline]
 exit_to_usermode_loop+0x1a9/0x200 arch/x86/entry/common.c:167
 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:271 [inline]
 do_syscall_64+0x413/0x4e0 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45d347
Code: 64 89 04 25 d0 02 00 00 58 5f ff d0 48 89 c7 e8 2f be ff ff 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 a6 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 4d 8c fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffee7927538 EFLAGS: 00000206 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 000000000045d347
RDX: 0000000000403720 RSI: 0000000000000002 RDI: 00007ffee79275e0
RBP: 0000000000000117 R08: 0000000000000000 R09: 000000000000000a
R10: 0000000000000005 R11: 0000000000000206 R12: 00007ffee7928670
R13: 00000000011f4940 R14: 0000000000000000 R15: 00007ffee7928670
Modules linked in:
---[ end trace 46e441d206f44795 ]---
RIP: 0010:submit_bh_wbc+0x4ee/0x700 fs/buffer.c:3054
Code: 33 45 89 65 10 4c 89 ef e8 3f e2 6c 01 31 c0 48 83 c4 20 5b 41 5c 41 5d 41 5e 41 5f 5d c3 f0 80 63 01 f7 e9 b8 fb ff ff 0f 0b <0f> 0b 0f 0b 0f 0b 0f 0b 0f 0b e8 73 ed ea ff eb c6 e8 cc ec ea ff
RSP: 0018:ffff888094197c60 EFLAGS: 00010246
RAX: 0000000000000005 RBX: ffff888087282150 RCX: 0000000000000000
RDX: 1ffff11010e5042a RSI: 0000000000000800 RDI: 0000000000000001
RBP: ffff888094197ca8 R08: 0000000000000000 R09: ffffed1010e50436
R10: ffffed1010e50436 R11: ffff8880872821b3 R12: 0000000000000800
R13: 0000000000000800 R14: 0000000000000000 R15: 0000000000000000
FS:  00000000011f3940(0000) GS:ffff8880aea00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000143b978 CR3: 000000007e5de000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400