syzbot


WARNING in fat12_ent_blocknr

Status: fixed on 2020/09/16 22:51
Subsystems: exfat
[Documentation on labels]
Reported-by: syzbot+756199124937b31a9b7e@syzkaller.appspotmail.com
Fix commit: a090a5a7d73f fat: fix fat_ra_init() for data clusters == 0
First crash: 1437d, last: 1409d
Discussions (5)
Title Replies (including bot) Last reply
[PATCH 5.8 000/148] 5.8.4-rc1 review 152 (152) 2020/08/24 16:54
[PATCH AUTOSEL 5.8 01/27] scsi: ufs: Add DELAY_BEFORE_LPM quirk for Micron devices 27 (27) 2020/08/20 00:01
[patch 110/165] fat: fix fat_ra_init() for data clusters == 0 1 (1) 2020/08/12 01:36
[PATCH] fat: Fix fat_ra_init() for data clusters == 0 1 (1) 2020/07/11 11:28
WARNING in fat12_ent_blocknr 0 (1) 2020/07/10 16:14

Sample crash report:
------------[ cut here ]------------
WARNING: CPU: 0 PID: 28636 at fs/fat/fatent.c:27 fat12_ent_blocknr+0x198/0x1f0 fs/fat/fatent.c:27
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 28636 Comm: syz-executor.2 Not tainted 5.8.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x18f/0x20d lib/dump_stack.c:118
 panic+0x2e3/0x75c kernel/panic.c:231
 __warn.cold+0x20/0x45 kernel/panic.c:600
 report_bug+0x1bd/0x210 lib/bug.c:198
 handle_bug+0x38/0x90 arch/x86/kernel/traps.c:235
 exc_invalid_op+0x13/0x40 arch/x86/kernel/traps.c:255
 asm_exc_invalid_op+0x12/0x20 arch/x86/include/asm/idtentry.h:540
RIP: 0010:fat12_ent_blocknr+0x198/0x1f0 fs/fat/fatent.c:27
Code: ff df 48 c1 ea 03 d3 fb 01 eb 80 3c 02 00 48 63 db 75 4d 49 89 1e 48 83 c4 08 5b 5d 41 5c 41 5d 41 5e 41 5f c3 e8 d8 88 59 ff <0f> 0b e9 0a ff ff ff e8 fc ea 98 ff eb b7 e8 05 eb 98 ff eb 83 4c
RSP: 0018:ffffc90001847a30 EFLAGS: 00010212
RAX: 000000000000065e RBX: 0000000000000003 RCX: ffffc90009129000
RDX: 0000000000040000 RSI: ffffffff821a2ed8 RDI: 0000000000000006
RBP: 0000000000000002 R08: 0000000000000000 R09: ffff888052c2804f
R10: 0000000000000002 R11: 0000000000000000 R12: ffff88805bf96000
R13: ffffc90001847ab8 R14: ffffc90001847ac8 R15: ffff888052c28000
 fat_ra_init.constprop.0.isra.0+0x1d3/0x3f0 fs/fat/fatent.c:665
 fat_count_free_clusters+0x230/0x950 fs/fat/fatent.c:726
 fat_statfs+0x3ac/0x4c0 fs/fat/inode.c:829
 statfs_by_dentry+0x133/0x210 fs/statfs.c:64
 vfs_statfs fs/statfs.c:88 [inline]
 user_statfs+0xa9/0x160 fs/statfs.c:103
 __do_sys_statfs+0x7a/0xf0 fs/statfs.c:193
 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45cce9
Code: 2d b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 fb b5 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fe2e0138c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000089
RAX: ffffffffffffffda RBX: 0000000000032c00 RCX: 000000000045cce9
RDX: 0000000000000000 RSI: 0000000020000240 RDI: 0000000020000200
RBP: 000000000078bfd8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078bfac
R13: 00007ffc822b4eff R14: 00007fe2e01399c0 R15: 000000000078bfac
Kernel Offset: disabled
Rebooting in 86400 seconds..

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/08/04 02:44 upstream 3208167a865e 196277c4 .config console log report ci-upstream-kasan-gce-root
2020/07/06 16:10 linux-next 9e50b94b3eb0 51095195 .config console log report ci-upstream-linux-next-kasan-gce-root
* Struck through repros no longer work on HEAD.