syzbot


BUG: unable to handle kernel NULL pointer dereference in __lookup_slow (3)

Status: upstream: reported C repro on 2024/04/28 08:01
Subsystems: overlayfs
[Documentation on labels]
Reported-by: syzbot+94891a5155abdf6821b7@syzkaller.appspotmail.com
First crash: 52d, last: 2d21h
Cause bisection: the issue happens on the oldest tested release (bisect log)
Crash: BUG: unable to handle kernel NULL pointer dereference in lookup_slow (log)
Repro: C syz .config
  
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [overlayfs?] BUG: unable to handle kernel NULL pointer dereference in __lookup_slow (3) 0 (1) 2024/04/28 08:01
Similar bugs (4)
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 1216d 1356d 19/27 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 1038d 1161d 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 1076d 1159d 0/27 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 1194d 1352d 1/1 fixed on 2021/04/10 11:48
Last patch testing requests (1)
Created Duration User Patch Repo Result
2024/05/17 21:02 11m retest repro upstream report log

Sample crash report:
overlayfs: fs on './file0' does not support file handles, falling back to index=off,nfs_export=off.
BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor instruction fetch in kernel mode
#PF: error_code(0x0010) - not-present page
PGD 8000000022852067 P4D 8000000022852067 PUD 2dc51067 PMD 0 
Oops: 0010 [#1] PREEMPT SMP KASAN PTI
CPU: 1 PID: 5070 Comm: syz-executor324 Not tainted 6.9.0-rc5-syzkaller-00036-g9d1ddab261f3 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
RIP: 0010:0x0
Code: Unable to access opcode bytes at 0xffffffffffffffd6.
RSP: 0018:ffffc9000352f1b8 EFLAGS: 00010246
RAX: 1ffffffff17b0bc0 RBX: ffffffff8bd85e00 RCX: ffff88807ef35a00
RDX: 0000000000000000 RSI: ffff8880207f85e0 RDI: ffff88807ebf8018
RBP: ffffc9000352f2d0 R08: ffffffff820b2843 R09: 1ffffffff28ed13f
R10: dffffc0000000000 R11: 0000000000000000 R12: dffffc0000000000
R13: ffff8880207f85e0 R14: 1ffff110040ff0bc R15: 1ffff920006a5e3c
FS:  0000555558bc6380(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 000000001cba8000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __lookup_slow+0x28c/0x3f0 fs/namei.c:1692
 lookup_slow fs/namei.c:1709 [inline]
 lookup_one_unlocked+0x1a4/0x290 fs/namei.c:2817
 ovl_lookup_positive_unlocked fs/overlayfs/namei.c:210 [inline]
 ovl_lookup_single+0x200/0xbd0 fs/overlayfs/namei.c:240
 ovl_lookup_layer+0x417/0x510 fs/overlayfs/namei.c:333
 ovl_lookup+0xcf7/0x2a60 fs/overlayfs/namei.c:1124
 lookup_open fs/namei.c:3475 [inline]
 open_last_lookups fs/namei.c:3566 [inline]
 path_openat+0x1033/0x3240 fs/namei.c:3796
 do_filp_open+0x235/0x490 fs/namei.c:3826
 do_sys_openat2+0x13e/0x1d0 fs/open.c:1406
 do_sys_open fs/open.c:1421 [inline]
 __do_sys_openat fs/open.c:1437 [inline]
 __se_sys_openat fs/open.c:1432 [inline]
 __x64_sys_openat+0x247/0x2a0 fs/open.c:1432
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd739fc9f39
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:00007ffc39adcc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 6e69666e6f636e75 RCX: 00007fd739fc9f39
RDX: 0000000000001200 RSI: 0000000020000340 RDI: 0000000000000003
RBP: 646165725f78616d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000246 R12: 0030656c69662f2e
R13: 7269647265776f6c R14: 0079616c7265766f R15: 2f31656c69662f2e
 </TASK>
Modules linked in:
CR2: 0000000000000000
---[ end trace 0000000000000000 ]---
RIP: 0010:0x0
Code: Unable to access opcode bytes at 0xffffffffffffffd6.
RSP: 0018:ffffc9000352f1b8 EFLAGS: 00010246
RAX: 1ffffffff17b0bc0 RBX: ffffffff8bd85e00 RCX: ffff88807ef35a00
RDX: 0000000000000000 RSI: ffff8880207f85e0 RDI: ffff88807ebf8018
RBP: ffffc9000352f2d0 R08: ffffffff820b2843 R09: 1ffffffff28ed13f
R10: dffffc0000000000 R11: 0000000000000000 R12: dffffc0000000000
R13: ffff8880207f85e0 R14: 1ffff110040ff0bc R15: 1ffff920006a5e3c
FS:  0000555558bc6380(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 000000001cba8000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Crashes (21):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/04/24 08:19 upstream 9d1ddab261f3 21339d7b .config strace log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-upstream-fs BUG: unable to handle kernel NULL pointer dereference in __lookup_slow
2024/06/12 20:14 upstream cea2a26553ac f815599d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs BUG: unable to handle kernel NULL pointer dereference in __lookup_slow
2024/06/11 07:39 upstream 83a7eefedc9b b7d9eb04 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs BUG: unable to handle kernel NULL pointer dereference in __lookup_slow
2024/06/11 07:07 upstream 83a7eefedc9b b7d9eb04 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs BUG: unable to handle kernel NULL pointer dereference in __lookup_slow
2024/05/03 20:17 upstream f03359bca01b dd26401e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs BUG: unable to handle kernel NULL pointer dereference in __lookup_slow
2024/04/28 20:23 upstream 2c8159388952 07b455f9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs BUG: unable to handle kernel NULL pointer dereference in __lookup_slow
2024/04/28 16:02 upstream 2c8159388952 07b455f9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs BUG: unable to handle kernel NULL pointer dereference in __lookup_slow
2024/04/27 16:48 upstream 5eb4573ea63d 07b455f9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs BUG: unable to handle kernel NULL pointer dereference in __lookup_slow
2024/04/27 00:31 upstream c942a0cd3603 059e9963 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs BUG: unable to handle kernel NULL pointer dereference in __lookup_slow
2024/04/26 03:06 upstream e33c4963bf53 8bdc0f22 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs BUG: unable to handle kernel NULL pointer dereference in __lookup_slow
2024/04/25 23:56 upstream e33c4963bf53 8bdc0f22 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs BUG: unable to handle kernel NULL pointer dereference in __lookup_slow
2024/04/25 16:42 upstream e88c4cfcb7b8 8bdc0f22 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs BUG: unable to handle kernel NULL pointer dereference in __lookup_slow
2024/04/25 13:18 upstream e88c4cfcb7b8 8bdc0f22 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs BUG: unable to handle kernel NULL pointer dereference in __lookup_slow
2024/04/25 11:22 upstream e88c4cfcb7b8 8bdc0f22 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs BUG: unable to handle kernel NULL pointer dereference in __lookup_slow
2024/04/25 11:20 upstream e88c4cfcb7b8 8bdc0f22 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs BUG: unable to handle kernel NULL pointer dereference in __lookup_slow
2024/04/24 22:39 upstream e88c4cfcb7b8 8bdc0f22 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs BUG: unable to handle kernel NULL pointer dereference in __lookup_slow
2024/04/24 22:06 upstream e88c4cfcb7b8 8bdc0f22 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs BUG: unable to handle kernel NULL pointer dereference in __lookup_slow
2024/04/24 13:07 upstream 9d1ddab261f3 21339d7b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs BUG: unable to handle kernel NULL pointer dereference in __lookup_slow
2024/04/24 10:46 upstream 9d1ddab261f3 21339d7b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs BUG: unable to handle kernel NULL pointer dereference in __lookup_slow
2024/04/24 08:05 upstream 9d1ddab261f3 21339d7b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs BUG: unable to handle kernel NULL pointer dereference in __lookup_slow
2024/04/24 07:50 upstream 9d1ddab261f3 21339d7b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs BUG: unable to handle kernel NULL pointer dereference in __lookup_slow
* Struck through repros no longer work on HEAD.