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BUG: unable to handle kernel NULL pointer dereference in __lookup_slow

Status: auto-obsoleted due to no activity on 2025/03/12 04:53
Bug presence: origin:lts-only
[Documentation on labels]
Reported-by: syzbot+9db6b2a6346d266bd206@syzkaller.appspotmail.com
First crash: 194d, last: 186d
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 1571d 1712d 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 1394d 1517d 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 1432d 1515d 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 1550d 1708d 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 done 135 195d 404d 0/28 auto-obsoleted due to no activity on 2025/01/31 21:09
▶ ▼ Last patch testing requests (3)
Created Duration User Patch Repo Result
2025/02/03 05:18 15m retest repro linux-5.15.y OK log
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:
udc-core: couldn't find an available UDC or it's busy
misc raw-gadget: fail, usb_gadget_probe_driver returned -16
BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor instruction fetch in kernel mode
#PF: error_code(0x0010) - not-present page
PGD 2531d067 P4D 2531d067 PUD 63e06067 PMD 0 
Oops: 0010 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 5331 Comm: syz.2.185 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:ffffc90003267198 EFLAGS: 00010246
RAX: 1ffffffff156df30 RBX: ffffffff8ab6f980 RCX: 0000000000080000
RDX: 0000000000000000 RSI: ffff888060d48bc0 RDI: ffff888055d04018
RBP: ffffc900032672b0 R08: ffffffff81d86ead R09: fffffbfff2d5f123
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: ffff888060d48bc0 R14: 1ffff1100c1a9178 R15: 1ffff9200064ce38
FS:  00007f3c534ba6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 0000000058f0e000 CR4: 00000000003526e0
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_slow+0x275/0x3d0 fs/namei.c:1663
 lookup_slow+0x53/0x70 fs/namei.c:1680
 walk_component+0x48c/0x610 fs/namei.c:1976
 link_path_walk+0x642/0xd90
 path_parentat fs/namei.c:2502 [inline]
 __filename_parentat+0x24c/0x6c0 fs/namei.c:2526
 filename_parentat fs/namei.c:2544 [inline]
 filename_create+0xf2/0x530 fs/namei.c:3816
 do_symlinkat+0xf6/0x600 fs/namei.c:4448
 __do_sys_symlinkat fs/namei.c:4475 [inline]
 __se_sys_symlinkat fs/namei.c:4472 [inline]
 __x64_sys_symlinkat+0x95/0xa0 fs/namei.c:4472
 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: 0033:0x7f3c55644849
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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f3c534ba058 EFLAGS: 00000246 ORIG_RAX: 000000000000010a
RAX: ffffffffffffffda RBX: 00007f3c55809fa0 RCX: 00007f3c55644849
RDX: 00000000200000c0 RSI: ffffffffffffff9c RDI: 0000000020000000
RBP: 00007f3c556b7986 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f3c55809fa0 R15: 00007ffdbcee1c68
 </TASK>
Modules linked in:
CR2: 0000000000000000
---[ end trace fd50996e7c3bc045 ]---
RIP: 0010:0x0
Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6.
RSP: 0018:ffffc90003267198 EFLAGS: 00010246
RAX: 1ffffffff156df30 RBX: ffffffff8ab6f980 RCX: 0000000000080000
RDX: 0000000000000000 RSI: ffff888060d48bc0 RDI: ffff888055d04018
RBP: ffffc900032672b0 R08: ffffffff81d86ead R09: fffffbfff2d5f123
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: ffff888060d48bc0 R14: 1ffff1100c1a9178 R15: 1ffff9200064ce38
FS:  00007f3c534ba6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 0000000058f0e000 CR4: 00000000003526e0
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
2024/12/02 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 02:53 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
2024/11/24 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.