bisecting fixing commit since 7d120bf21c05cbe30a679f0feeca884eeaceb069
building syzkaller on 64ca0a371100fc7dfdb20de9263763e46c88a436
testing commit 7d120bf21c05cbe30a679f0feeca884eeaceb069 with gcc (GCC) 8.1.0
kernel signature: e029b51482234d95d058e876d7f64bf30d137f9ff67c86ac63e036cfbd8224e7
all runs: crashed: kernel BUG at fs/buffer.c:LINE!
testing current HEAD 14cfdbd39e316efd91ae6e403ef8211f0b022603
testing commit 14cfdbd39e316efd91ae6e403ef8211f0b022603 with gcc (GCC) 8.1.0
kernel signature: 13132bdfaac5ef852f36c17f4f8edbe17df3d4457bcf3bc018982bb5d2c34fdd
all runs: crashed: kernel BUG at fs/buffer.c:LINE!
revisions tested: 2, total time: 28m17.680594373s (build: 18m38.576317538s, test: 8m16.499965927s)
the crash still happens on HEAD
commit msg: Linux 4.19.112
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: 1 PID: 12585 Comm: syz-executor.0 Not tainted 4.19.112-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 2f 14 6d 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 d3 ec ea ff eb c6 e8 2c ec ea ff
RSP: 0018:ffff8880986c79b0 EFLAGS: 00010246
RAX: 0000000000000005 RBX: ffff88809337ad20 RCX: 0000000000000000
RDX: 1ffff1101266f5a4 RSI: 0000000000000800 RDI: 0000000000000001
RBP: ffff8880986c79f8 R08: 0000000000000000 R09: ffffed101266f5b0
R10: ffffed101266f5b0 R11: ffff88809337ad83 R12: 0000000000000800
R13: 0000000000000800 R14: 0000000000000001 R15: 0000000000000000
FS:  00007f62a7a39700(0000) GS:ffff8880aeb00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1218f10df8 CR3: 000000009a339000 CR4: 00000000001406e0
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_fill_super+0x1bd0/0x3b10 fs/fat/inode.c:1863
 vfat_fill_super+0x15/0x20 fs/fat/namei_vfat.c:1048
 mount_bdev+0x278/0x330 fs/super.c:1158
 vfat_mount+0x10/0x20 fs/fat/namei_vfat.c:1055
 mount_fs+0x7f/0x2a2 fs/super.c:1261
 vfs_kern_mount.part.34+0x58/0x3d0 fs/namespace.c:961
 vfs_kern_mount fs/namespace.c:951 [inline]
 do_new_mount fs/namespace.c:2469 [inline]
 do_mount+0x36e/0x2410 fs/namespace.c:2799
 ksys_mount+0xba/0xe0 fs/namespace.c:3015
 __do_sys_mount fs/namespace.c:3029 [inline]
 __se_sys_mount fs/namespace.c:3026 [inline]
 __x64_sys_mount+0xb9/0x150 fs/namespace.c:3026
 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45d36a
Code: 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 00 66 90 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 2a 8c fb ff c3 66 0f 1f 84 00 00 00 00 00
RSP: 002b:00007f62a7a38a68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0000000000000007 RCX: 000000000045d36a
RDX: 00007f62a7a38ae0 RSI: 00000000200002c0 RDI: 00007f62a7a38b00
RBP: 000000000075bf20 R08: 00007f62a7a38b40 R09: 00007f62a7a38ae0
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f62a7a396d4
R13: 00000000004cae75 R14: 00000000004e4378 R15: 00000000ffffffff
Modules linked in:
---[ end trace 40e52764dd233841 ]---
RIP: 0010:submit_bh_wbc+0x4ee/0x700 fs/buffer.c:3054
Code: 33 45 89 65 10 4c 89 ef e8 2f 14 6d 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 d3 ec ea ff eb c6 e8 2c ec ea ff
RSP: 0018:ffff8880986c79b0 EFLAGS: 00010246
RAX: 0000000000000005 RBX: ffff88809337ad20 RCX: 0000000000000000
RDX: 1ffff1101266f5a4 RSI: 0000000000000800 RDI: 0000000000000001
RBP: ffff8880986c79f8 R08: 0000000000000000 R09: ffffed101266f5b0
R10: ffffed101266f5b0 R11: ffff88809337ad83 R12: 0000000000000800
R13: 0000000000000800 R14: 0000000000000001 R15: 0000000000000000
FS:  00007f62a7a39700(0000) GS:ffff8880aeb00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000c44c70 CR3: 000000009a339000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400