bisecting fixing commit since 0c88e405c97ed1828443b67891e6d4bb6e56cd4e
building syzkaller on 1a1f4bd8c48f86af4bc94a2e3a86fc0de9c52c93
testing commit 0c88e405c97ed1828443b67891e6d4bb6e56cd4e with gcc (GCC) 8.1.0
kernel signature: ef368583f2f4df6d020820326a257c82d46b0b0de4933371f249355f555a7d1d
run #0: crashed: general protection fault in bdevname
run #1: crashed: kernel BUG at fs/buffer.c:LINE!
run #2: crashed: general protection fault in bdevname
run #3: crashed: general protection fault in bdevname
run #4: crashed: kernel BUG at fs/buffer.c:LINE!
run #5: crashed: kernel BUG at fs/buffer.c:LINE!
run #6: crashed: kernel BUG at fs/buffer.c:LINE!
run #7: crashed: kernel BUG at fs/buffer.c:LINE!
run #8: crashed: kernel BUG at fs/buffer.c:LINE!
run #9: crashed: general protection fault in bdevname
testing current HEAD 13d2ce42de8cb98ff952f8de6307f896203854c2
testing commit 13d2ce42de8cb98ff952f8de6307f896203854c2 with gcc (GCC) 8.1.0
kernel signature: 001d72ca022e8761000acb49217d42a5c98d1bc711a52c98ebd0fbc7855a4669
run #0: crashed: kernel BUG at fs/buffer.c:LINE!
run #1: crashed: kernel BUG at fs/buffer.c:LINE!
run #2: crashed: general protection fault in bdevname
run #3: crashed: kernel BUG at fs/buffer.c:LINE!
run #4: crashed: kernel BUG at fs/buffer.c:LINE!
run #5: crashed: kernel BUG at fs/buffer.c:LINE!
run #6: crashed: kernel BUG at fs/buffer.c:LINE!
run #7: crashed: kernel BUG at fs/buffer.c:LINE!
run #8: crashed: kernel BUG at fs/buffer.c:LINE!
run #9: crashed: kernel BUG at fs/buffer.c:LINE!
revisions tested: 2, total time: 24m43.834342939s (build: 17m13.889498942s, test: 6m45.559796794s)
the crash still happens on HEAD
commit msg: Linux 4.19.163
crash: kernel BUG at fs/buffer.c:LINE!
EXT4-fs (loop3): mount failed
EXT4-fs error (device loop1): ext4_fill_super:4448: inode #2: comm syz-executor.1: iget: root inode unallocated
EXT4-fs (loop1): get root inode failed
EXT4-fs (loop1): mount failed
------------[ cut here ]------------
kernel BUG at fs/buffer.c:3049!
EXT4-fs error (device loop0): ext4_fill_super:4448: inode #2: comm syz-executor.0: iget: root inode unallocated
EXT4-fs error (device loop3): ext4_fill_super:4448: inode #2: comm syz-executor.3: iget: root inode unallocated
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 11515 Comm: syz-executor.4 Not tainted 4.19.163-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:submit_bh_wbc+0x4e5/0x6f0 fs/buffer.c:3049
EXT4-fs error (device loop5): ext4_fill_super:4448: inode #2: comm syz-executor.5: iget: root inode unallocated
Code: 33 45 89 65 10 4c 89 ef e8 98 75 97 01 31 c0 48 83 c4 20 5b 41 5c 41 5d 41 5e 41 5f 5d c3 f0 80 63 01 f7 e9 c1 fb ff ff 0f 0b <0f> 0b 0f 0b 0f 0b 0f 0b 0f 0b e8 cc fb e9 ff eb c6 e8 25 fb e9 ff
RSP: 0018:ffff8881c2817800 EFLAGS: 00010246
RAX: 0000000000000004 RBX: ffff8881c6612b28 RCX: 0000000000000000
RDX: 1ffff11038cc2565 RSI: 0000000000003000 RDI: 0000000000000000
RBP: ffff8881c2817848 R08: 0000000000000000 R09: ffffed1038cc2571
R10: ffffed1038cc2571 R11: ffff8881c6612b8b R12: 0000000000003000
R13: ffff8881ecf2a140 R14: 0000000000000040 R15: 0000000000000000
FS:  00007fc2746de700(0000) GS:ffff8881f6500000(0000) knlGS:0000000000000000
EXT4-fs (loop3): get root inode failed
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000016a9e60 CR3: 00000001d20ff006 CR4: 00000000001606e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 submit_bh+0xe/0x10 fs/buffer.c:3096
 read_mmp_block+0x115/0x580 fs/ext4/mmp.c:91
EXT4-fs (loop5): get root inode failed
 ext4_multi_mount_protect+0x45d/0x9c0 fs/ext4/mmp.c:358
 ext4_fill_super+0x97a6/0xb650 fs/ext4/super.c:4285
EXT4-fs (loop0): get root inode failed
 mount_bdev+0x26f/0x330 fs/super.c:1158
 ext4_mount+0x10/0x20 fs/ext4/super.c:6049
EXT4-fs error (device loop1): ext4_fill_super:4448: inode #2: comm syz-executor.1: iget: root inode unallocated
 mount_fs+0x7f/0x2a2 fs/super.c:1261
 vfs_kern_mount.part.11+0x58/0x3d0 fs/namespace.c:961
 vfs_kern_mount fs/namespace.c:951 [inline]
 do_new_mount fs/namespace.c:2469 [inline]
 do_mount+0x376/0x2710 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
EXT4-fs (loop1): get root inode failed
RIP: 0033:0x46090a
Code: b8 a6 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 ad 89 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 8a 89 fb ff c3 66 0f 1f 84 00 00 00 00 00
RSP: 002b:00007fc2746dda88 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fc2746ddb20 RCX: 000000000046090a
RDX: 0000000020000040 RSI: 0000000020000100 RDI: 00007fc2746ddae0
RBP: 00007fc2746ddae0 R08: 00007fc2746ddb20 R09: 0000000020000040
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000020000040
R13: 0000000020000100 R14: 0000000020000580 R15: 00000000200000c0
Modules linked in:
---[ end trace a4ebfd39f6a2bf0c ]---
EXT4-fs (loop0): mount failed
RIP: 0010:submit_bh_wbc+0x4e5/0x6f0 fs/buffer.c:3049
EXT4-fs (loop3): mount failed
EXT4-fs error (device loop2): ext4_fill_super:4448: inode #2: comm syz-executor.2: iget: root inode unallocated
EXT4-fs (loop1): mount failed
EXT4-fs (loop2): get root inode failed
EXT4-fs (loop5): mount failed
EXT4-fs (loop2): mount failed
Code: 33 45 89 65 10 4c 89 ef e8 98 75 97 01 31 c0 48 83 c4 20 5b 41 5c 41 5d 41 5e 41 5f 5d c3 f0 80 63 01 f7 e9 c1 fb ff ff 0f 0b <0f> 0b 0f 0b 0f 0b 0f 0b 0f 0b e8 cc fb e9 ff eb c6 e8 25 fb e9 ff
RSP: 0018:ffff8881c2817800 EFLAGS: 00010246
RAX: 0000000000000004 RBX: ffff8881c6612b28 RCX: 0000000000000000
RDX: 1ffff11038cc2565 RSI: 0000000000003000 RDI: 0000000000000000
RBP: ffff8881c2817848 R08: 0000000000000000 R09: ffffed1038cc2571
R10: ffffed1038cc2571 R11: ffff8881c6612b8b R12: 0000000000003000
R13: ffff8881ecf2a140 R14: 0000000000000040 R15: 0000000000000000
FS:  00007fc2746de700(0000) GS:ffff8881f6400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f40517d2000 CR3: 00000001d20ff003 CR4: 00000000001606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400