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BUG: unable to handle kernel NULL pointer dereference in __lookup_slow

Status: upstream: reported C repro on 2024/11/24 01:13
Bug presence: origin:lts-only
[Documentation on labels]
Reported-by: syzbot+9db6b2a6346d266bd206@syzkaller.appspotmail.com
First crash: 27d, last: 19d
Fix commit to backport (bisect log) :
tree: upstream
commit c8b359dddb418c60df1a69beea01d1b3322bfe83
Author: Vasiliy Kovalev <kovalev@altlinux.org>
Date: Tue Nov 19 15:58:17 2024 +0000

  ovl: Filter invalid inodes with missing lookup function

  
▶ ▼ Bug presence (2)
Date Name Commit Repro Result
2024/11/24 linux-5.15.y (ToT) 0a51d2d4527b C [report] BUG: unable to handle kernel NULL pointer dereference in __lookup_slow
2024/11/24 upstream (ToT) 9f16d5e6f220 C Didn't crash
▶ ▼ Similar bugs (5)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream BUG: unable to handle kernel NULL pointer dereference in __lookup_slow reiserfs C inconclusive done 3 1405d 1545d 19/28 fixed on 2021/03/10 01:48
linux-4.19 BUG: unable to handle kernel NULL pointer dereference in __lookup_slow (2) C done 15 1227d 1350d 1/1 fixed on 2021/09/13 16:54
upstream BUG: unable to handle kernel NULL pointer dereference in __lookup_slow (2) reiserfs C inconclusive 4 1265d 1348d 0/28 auto-obsoleted due to no activity on 2023/04/14 10:28
linux-4.19 BUG: unable to handle kernel NULL pointer dereference in __lookup_slow C done 23 1383d 1541d 1/1 fixed on 2021/04/10 11:48
upstream BUG: unable to handle kernel NULL pointer dereference in __lookup_slow (3) overlayfs C inconclusive 135 28d 237d 0/28 upstream: reported C repro on 2024/04/28 08:01
▶ ▼ Last patch testing requests (2)
Created Duration User Patch Repo Result
2024/12/16 08:59 19m retest repro linux-5.15.y OK log
2024/12/16 08:59 16m retest repro linux-5.15.y OK log
▶ ▼ Fix bisection attempts (1)
Created Duration User Patch Repo Result
2024/12/12 15:31 8h01m fix candidate upstream OK (1) job log

Sample crash report:
loop0: detected capacity change from 0 to 64
BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor instruction fetch in kernel mode
#PF: error_code(0x0010) - not-present page
PGD 20e46067 P4D 20e46067 PUD 2321a067 PMD 0 
Oops: 0010 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 4161 Comm: syz-executor441 Not tainted 5.15.173-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:0x0
Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6.
RSP: 0018:ffffc90002a77318 EFLAGS: 00010246
RAX: 1ffffffff152df28 RBX: ffffffff8a96f940 RCX: ffff88802a821dc0
RDX: 0000000000000000 RSI: ffff8880174782f0 RDI: ffff88806ec4c018
RBP: ffffc90002a77430 R08: ffffffff81d86ead R09: fffffbfff2d1a861
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: ffff8880174782f0 R14: 1ffff11002e8f05e R15: 1ffff9200054ee68
FS:  000055556cc65380(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 000000007a933000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __lookup_slow+0x275/0x3d0 fs/namei.c:1663
 lookup_slow fs/namei.c:1680 [inline]
 lookup_one_unlocked+0x19c/0x280 fs/namei.c:2779
 ovl_lookup_positive_unlocked fs/overlayfs/namei.c:205 [inline]
 ovl_lookup_single+0x62/0x840 fs/overlayfs/namei.c:230
 ovl_lookup_layer+0x413/0x510 fs/overlayfs/namei.c:314
 ovl_lookup+0xb77/0x1f10 fs/overlayfs/namei.c:914
 lookup_open fs/namei.c:3440 [inline]
 open_last_lookups fs/namei.c:3532 [inline]
 path_openat+0x111d/0x2f20 fs/namei.c:3739
 do_filp_open+0x21c/0x460 fs/namei.c:3769
 do_sys_openat2+0x13b/0x4f0 fs/open.c:1253
 do_sys_open fs/open.c:1269 [inline]
 __do_sys_openat fs/open.c:1285 [inline]
 __se_sys_openat fs/open.c:1280 [inline]
 __x64_sys_openat+0x243/0x290 fs/open.c:1280
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fd7ffd1c709
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 61 17 00 00 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffc74aff348 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0030656c69662f2e RCX: 00007fd7ffd1c709
RDX: 0000000000000000 RSI: 0000000020000040 RDI: ffffffffffffff9c
RBP: 00007fd7ffd8f610 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffc74aff518 R14: 0000000000000001 R15: 0000000000000001
 </TASK>
Modules linked in:
CR2: 0000000000000000
---[ end trace c1369ba438c8e51d ]---
RIP: 0010:0x0
Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6.
RSP: 0018:ffffc90002a77318 EFLAGS: 00010246
RAX: 1ffffffff152df28 RBX: ffffffff8a96f940 RCX: ffff88802a821dc0
RDX: 0000000000000000 RSI: ffff8880174782f0 RDI: ffff88806ec4c018
RBP: ffffc90002a77430 R08: ffffffff81d86ead R09: fffffbfff2d1a861
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: ffff8880174782f0 R14: 1ffff11002e8f05e R15: 1ffff9200054ee68
FS:  000055556cc65380(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 000000007a933000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/11/24 02:53 linux-5.15.y 0a51d2d4527b 68da6d95 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan BUG: unable to handle kernel NULL pointer dereference in __lookup_slow
2024/12/02 04:53 linux-5.15.y 0a51d2d4527b 68914665 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan BUG: unable to handle kernel NULL pointer dereference in __lookup_slow
2024/11/24 02:21 linux-5.15.y 0a51d2d4527b 68da6d95 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan BUG: unable to handle kernel NULL pointer dereference in __lookup_slow
2024/11/24 01:49 linux-5.15.y 0a51d2d4527b 68da6d95 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan BUG: unable to handle kernel NULL pointer dereference in __lookup_slow
2024/11/24 01:12 linux-5.15.y 0a51d2d4527b 68da6d95 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan BUG: unable to handle kernel NULL pointer dereference in __lookup_slow
* Struck through repros no longer work on HEAD.