syzbot


kernel BUG in ext4_writepages

Status: upstream: reported C repro on 2022/05/09 19:22
Reported-by: syzbot+bd13648a53ed6933ca49@syzkaller.appspotmail.com
First crash: 54d, last: 24d

Cause bisection: failed (bisect log)
similar bugs (9):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.19 kernel BUG at fs/ext4/inode.c:LINE! C error 3 54d 627d 0/1 upstream: reported C repro on 2020/10/14 01:19
android-54 kernel BUG at fs/ext4/inode.c:LINE! C 111 54d 900d 0/2 upstream: reported C repro on 2020/01/14 12:13
linux-4.14 kernel BUG at fs/ext4/inode.c:LINE! C 4 24d 555d 0/1 upstream: reported C repro on 2020/12/25 03:51
upstream kernel BUG in mpage_prepare_extent_to_map C done 108 2d03h 397d 0/22 upstream: reported C repro on 2021/05/31 07:15
upstream kernel BUG at fs/ext4/inode.c:LINE! C done 9 550d 675d 21/22 fixed on 2021/03/10 01:48
android-49 kernel BUG at fs/ext4/inode.c:LINE! C 280 1249d 1178d 0/3 public: reported C repro on 2019/04/11 08:44
android-414 kernel BUG at fs/ext4/inode.c:LINE! 1 1324d 1176d 0/1 auto-closed as invalid on 2019/05/15 13:37
android-5-10 kernel BUG in mpage_prepare_extent_to_map C error 254 74d 242d 2/3 fixed on 2022/04/21 04:24
android-44 kernel BUG at fs/ext4/inode.c:LINE! C 110 1266d 1178d 0/2 public: reported C repro on 2019/04/11 08:44
Patch testing requests:
Created Duration User Patch Repo Result
2022/05/19 23:01 13m tadeusz.struk@linaro.org patch git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master OK
2022/05/19 22:52 14m tadeusz.struk@linaro.org patch android12-5.10-lts OK
2022/05/19 22:51 6m tadeusz.struk@linaro.org patch git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master error

Sample crash report:
EXT4-fs (loop0): mounted filesystem without journal. Opts: ,errors=continue
------------[ cut here ]------------
kernel BUG at fs/ext4/inode.c:2753!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 372 Comm: syz-executor373 Not tainted 5.10.112-syzkaller-00287-gde64d941a71a #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:ext4_writepages+0x36ca/0x36f0 fs/ext4/inode.c:2752
Code: c6 31 ff e8 d8 5d 90 ff 84 db 75 2c e8 bf 5a 90 ff 49 bf 00 00 00 00 00 fc ff df 4c 8b 64 24 48 e9 3f f7 ff ff e8 a6 5a 90 ff <0f> 0b e8 9f 5a 90 ff e8 b9 fd 23 ff eb 9d e8 93 5a 90 ff e8 ad fd
RSP: 0018:ffffc90000ae7300 EFLAGS: 00010293
RAX: ffffffff81dc561a RBX: 0000008000000000 RCX: ffff88810658e2c0
RDX: 0000000000000000 RSI: 0000008000000000 RDI: 0000000000000000
RBP: ffffc90000ae76f0 R08: ffffffff81dc25e7 R09: ffffed1021c6800b
R10: ffffed1021c6800b R11: 1ffff11021c6800a R12: ffffc90000ae75c0
R13: 0000000000000001 R14: 0000008410000000 R15: ffffc90000ae7860
FS:  00007f030cfb9700(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005599f528b520 CR3: 000000011e5e5000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 do_writepages+0x13a/0x280 mm/page-writeback.c:2358
 __filemap_fdatawrite_range+0x354/0x420 mm/filemap.c:427
 file_write_and_wait_range+0x89/0x120 mm/filemap.c:766
 ext4_sync_file+0x19e/0x9d0 fs/ext4/fsync.c:151
 vfs_fsync_range+0x17b/0x190 fs/sync.c:200
 generic_write_sync include/linux/fs.h:2796 [inline]
 ext4_buffered_write_iter+0x565/0x610 fs/ext4/file.c:280
 ext4_file_write_iter+0x192/0x1cd0 fs/ext4/file.c:683
 call_write_iter include/linux/fs.h:1947 [inline]
 new_sync_write fs/read_write.c:518 [inline]
 vfs_write+0xc1c/0xf40 fs/read_write.c:605
 ksys_write+0x198/0x2c0 fs/read_write.c:658
 __do_sys_write fs/read_write.c:670 [inline]
 __se_sys_write fs/read_write.c:667 [inline]
 __x64_sys_write+0x7b/0x90 fs/read_write.c:667
 do_syscall_64+0x34/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f030d00bcc9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f030cfb92f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f030d090420 RCX: 00007f030d00bcc9
RDX: 0000000000000016 RSI: 0000000020002580 RDI: 0000000000000007
RBP: 00007f030d05e04c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0030656c69662f2e
R13: e5d26e84aa4cf3c6 R14: 65732f636f72702f R15: 00007f030d090428
Modules linked in:
---[ end trace 89f6fade01325723 ]---
RIP: 0010:ext4_writepages+0x36ca/0x36f0 fs/ext4/inode.c:2752
Code: c6 31 ff e8 d8 5d 90 ff 84 db 75 2c e8 bf 5a 90 ff 49 bf 00 00 00 00 00 fc ff df 4c 8b 64 24 48 e9 3f f7 ff ff e8 a6 5a 90 ff <0f> 0b e8 9f 5a 90 ff e8 b9 fd 23 ff eb 9d e8 93 5a 90 ff e8 ad fd
RSP: 0018:ffffc90000ae7300 EFLAGS: 00010293
RAX: ffffffff81dc561a RBX: 0000008000000000 RCX: ffff88810658e2c0
RDX: 0000000000000000 RSI: 0000008000000000 RDI: 0000000000000000
RBP: ffffc90000ae76f0 R08: ffffffff81dc25e7 R09: ffffed1021c6800b
R10: ffffed1021c6800b R11: 1ffff11021c6800a R12: ffffc90000ae75c0
R13: 0000000000000001 R14: 0000008410000000 R15: ffffc90000ae7860
FS:  00007f030cfb9700(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005599f528b520 CR3: 000000011e5e5000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Fix bisection attempts:
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-android-5-10 2022/06/08 19:48 android12-5.10-lts fdd06dc6b0f8 8b277b8e .config log report syz C
Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-android-5-10 2022/05/09 19:21 android12-5.10-lts de64d941a71a 8b277b8e .config log report syz C kernel BUG in ext4_writepages