WARNING in inc_nlink

Status: fixed on 2020/09/16 22:51
Reported-by: syzbot+a9ac3de1b5de5fb10efc@syzkaller.appspotmail.com
Fix commit: facb03dddec0 fs/minix: don't allow getting deleted inodes
First crash: 2319d, last: 2215d
Cause bisection: the issue happens on the oldest tested release (bisect log)
Crash: WARNING in sysfs_warn_dup (log)
Repro: C syz .config
  
▶ ▼ Discussions (10)
Title Replies (including bot) Last reply
[PATCH 4.4 000/149] 4.4.233-rc1 review 163 (163) 2020/10/31 20:04
[PATCH 4.9 000/212] 4.9.233-rc1 review 220 (220) 2020/08/21 09:40
[PATCH 4.19 000/168] 4.19.140-rc1 review 183 (183) 2020/08/21 08:05
[PATCH 4.14 000/228] 4.14.194-rc1 review 234 (234) 2020/08/21 06:59
[PATCH 5.8 000/464] 5.8.2-rc1 review 475 (475) 2020/08/19 06:11
[PATCH 5.4 000/270] 5.4.59-rc1 review 275 (275) 2020/08/18 22:37
[PATCH 5.7 000/393] 5.7.16-rc1 review 398 (398) 2020/08/18 22:36
[patch 099/165] fs/minix: don't allow getting deleted inodes 1 (1) 2020/08/12 01:35
[PATCH 0/6] fs/minix: fix syzbot bugs and set s_maxbytes 10 (10) 2020/07/07 20:34
WARNING in inc_nlink 0 (1) 2020/03/31 17:21
▶ ▼ Similar bugs (10)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.6 WARNING in inc_nlink origin:lts-only -1 syz, C error 55 37d 410d 0/2 upstream: reported C repro on 2025/06/21 08:35
linux-4.19 WARNING in inc_nlink (2) -1 syz, C error 102 1347d 2103d 0/1 upstream: reported C repro on 2020/11/01 15:25
linux-5.15 WARNING in inc_nlink origin:lts-only -1 syz, C done 813 26d 1234d 0/3 upstream: reported C repro on 2023/03/20 05:26
upstream WARNING in inc_nlink (2) fs -1 syz, C inconclusive done 21 1611d 1948d 20/29 fixed on 2022/03/08 16:11
upstream WARNING in inc_nlink (3) fs prio:low -1 syz, C error error 7067 1d00h 1602d 0/29 upstream: reported C repro on 2022/03/17 16:37
linux-6.1 WARNING in inc_nlink -1 81 1191d 1213d 0/3 auto-obsoleted due to no activity on 2023/07/31 15:23
linux-4.19 WARNING in inc_nlink -1 syz, C done 8 2177d 2326d 1/1 fixed on 2020/09/18 07:23
linux-4.14 WARNING in inc_nlink -1 syz, C done 21 2185d 2327d 1/1 fixed on 2020/09/11 09:49
linux-4.14 WARNING in inc_nlink (2) -1 syz, C 47 1263d 2098d 0/1 upstream: reported C repro on 2020/11/06 09:55
linux-6.1 WARNING in inc_nlink (2) origin:upstream missing-backport -1 syz, C done 568 17d 951d 0/3 upstream: reported C repro on 2023/12/28 21:17

Sample crash report:
MINIX-fs: mounting unchecked file system, running fsck is recommended
------------[ cut here ]------------
WARNING: CPU: 0 PID: 7197 at fs/inode.c:360 inc_nlink+0x144/0x160 fs/inode.c:360
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 7197 Comm: syz-executor186 Not tainted 5.7.0-rc6-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+0x188/0x20d lib/dump_stack.c:118
 panic+0x2e3/0x75c kernel/panic.c:221
 __warn.cold+0x2f/0x35 kernel/panic.c:582
 report_bug+0x27b/0x2f0 lib/bug.c:195
 fixup_bug arch/x86/kernel/traps.c:175 [inline]
 fixup_bug arch/x86/kernel/traps.c:170 [inline]
 do_error_trap+0x12b/0x220 arch/x86/kernel/traps.c:267
 do_invalid_op+0x32/0x40 arch/x86/kernel/traps.c:286
 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1027
RIP: 0010:inc_nlink+0x144/0x160 fs/inode.c:360
Code: ff 4c 89 e7 e8 ed 70 ee ff e9 42 ff ff ff 4c 89 e7 e8 70 70 ee ff e9 fc fe ff ff 4c 89 e7 e8 63 70 ee ff eb d4 e8 bc 8f b0 ff <0f> 0b e9 6e ff ff ff e8 60 70 ee ff e9 44 ff ff ff e8 56 70 ee ff
RSP: 0018:ffffc90001657d88 EFLAGS: 00010293
RAX: ffff8880962aa600 RBX: ffff888087318a00 RCX: ffffffff81c2a4d0
RDX: 0000000000000000 RSI: ffffffff81c2a564 RDI: 0000000000000007
RBP: 0000000000000000 R08: ffff8880962aa600 R09: ffffed1015440757
R10: ffff8880aa203ab3 R11: ffffed1015440756 R12: ffff888087318a48
R13: ffff8880896a8450 R14: ffff8880896a84b0 R15: 0000000000000000
 inode_inc_link_count include/linux/fs.h:2204 [inline]
 minix_mkdir+0x71/0x1b0 fs/minix/namei.c:117
 vfs_mkdir+0x419/0x690 fs/namei.c:3625
 do_mkdirat+0x21e/0x280 fs/namei.c:3648
 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3
RIP: 0033:0x444a59
Code: 0d d8 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 db d7 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fff6ab18768 EFLAGS: 00000246 ORIG_RAX: 0000000000000053
RAX: ffffffffffffffda RBX: 00007fff6ab18770 RCX: 0000000000444a59
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000240
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000400e40
R10: 00007fff6ab18640 R11: 0000000000000246 R12: 00000000004026c0
R13: 0000000000402750 R14: 0000000000000000 R15: 0000000000000000
Kernel Offset: disabled
Rebooting in 86400 seconds..

Crashes (26):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/05/24 22:04 upstream caffb99b6929 bd28eb9d .config console log report syz C ci-upstream-kasan-gce-root
2020/05/24 20:31 upstream caffb99b6929 bd28eb9d .config console log report syz C ci-upstream-kasan-gce-selinux-root
2020/05/23 23:05 upstream 423b8baf18a8 9682898d .config console log report syz C ci-upstream-kasan-gce-smack-root
2020/04/25 01:19 upstream b4f633221f0a 03d97a1b .config console log report syz C ci-upstream-kasan-gce-selinux-root
2020/04/25 00:52 upstream b4f633221f0a 03d97a1b .config console log report syz C ci-upstream-kasan-gce-smack-root
2020/04/18 03:03 upstream 95988fbc7c31 435c6d53 .config console log report syz C ci-upstream-kasan-gce-selinux-root
2020/04/18 02:36 upstream 95988fbc7c31 435c6d53 .config console log report syz C ci-upstream-kasan-gce-smack-root
2020/04/16 17:31 upstream 00086336a8d9 c743fcb3 .config console log report syz C ci-upstream-kasan-gce-smack-root
2020/04/16 16:29 upstream 00086336a8d9 c743fcb3 .config console log report syz C ci-upstream-kasan-gce-selinux-root
2020/04/16 15:00 upstream 00086336a8d9 c743fcb3 .config console log report syz C ci-upstream-kasan-gce-root
2020/04/15 06:14 upstream 8632e9b5645b 3f3c5574 .config console log report syz C ci-upstream-kasan-gce-root
2020/04/13 17:59 upstream 8f3d9f354286 17a986e5 .config console log report syz C ci-upstream-kasan-gce-selinux-root
2020/04/11 22:19 upstream 5b8b9d0c6d0e a8c6a3f8 .config console log report syz C ci-upstream-kasan-gce-root
2020/03/30 05:39 upstream e595dd94515e 05736b29 .config console log report syz C ci-upstream-kasan-gce-root
2020/05/21 08:37 linux-next ac935d227366 c61086ab .config console log report syz C ci-upstream-linux-next-kasan-gce-root
2020/04/25 23:48 linux-next ac935d227366 b8bb8e5f .config console log report syz C ci-upstream-linux-next-kasan-gce-root
2020/04/20 01:30 linux-next ac935d227366 9f7c6d12 .config console log report syz C ci-upstream-linux-next-kasan-gce-root
2020/04/19 00:32 linux-next ac935d227366 365fba24 .config console log report syz C ci-upstream-linux-next-kasan-gce-root
2020/04/16 13:07 linux-next ac935d227366 c743fcb3 .config console log report syz C ci-upstream-linux-next-kasan-gce-root
2020/07/12 20:34 upstream 0aea6d5c5be3 115e1930 .config console log report ci-upstream-kasan-gce-root
2020/07/11 20:21 upstream a581387e415b 18d18b59 .config console log report ci-upstream-kasan-gce-smack-root
2020/07/07 13:13 upstream 7cc2a8ea1048 51095195 .config console log report ci-upstream-kasan-gce-selinux-root
2020/07/07 06:21 upstream 7cc2a8ea1048 51095195 .config console log report ci-upstream-kasan-gce-smack-root
2020/04/07 04:30 upstream 7e63420847ae 99a96044 .config console log report ci-upstream-kasan-gce-selinux-root
2020/03/30 05:20 upstream e595dd94515e 05736b29 .config console log report ci-upstream-kasan-gce-root
2020/04/03 06:47 linux-next 770fbb32d34e a34e2c33 .config console log report ci-upstream-linux-next-kasan-gce-root
* Struck through repros no longer work on HEAD.