syzbot


BUG: unable to handle kernel NULL pointer dereference in lookup_one_unlocked

Status: upstream: reported C repro on 2024/11/16 21:56
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+a8c9d476508bd14a90e5@syzkaller.appspotmail.com
First crash: 25d, last: 25d
Discussions (3)
Title Replies (including bot) Last reply
[PATCH] bfs: validate inode vtype and discard invalid entries 1 (1) 2024/11/23 17:24
[PATCH v2] ovl: Filter invalid inodes with missing lookup function 2 (2) 2024/11/20 12:34
[PATCH] ovl: Add check for missing lookup operation on inode 2 (2) 2024/11/18 18:54
Bug presence (1)
Date Name Commit Repro Result
2024/11/18 upstream (ToT) adc218676eef C [report] BUG: unable to handle kernel NULL pointer dereference in lookup_one_unlocked
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 BUG: unable to handle kernel NULL pointer dereference in lookup_one_unlocked origin:upstream C error 13 3d04h 104d 0/3 upstream: reported C repro on 2024/08/30 03:46

Sample crash report:
loop0: detected capacity change from 0 to 64
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
Mem abort info:
  ESR = 0x0000000086000006
  EC = 0x21: IABT (current EL), IL = 32 bits
  SET = 0, FnV = 0
  EA = 0, S1PTW = 0
  FSC = 0x06: level 2 translation fault
user pgtable: 4k pages, 48-bit VAs, pgdp=0000000110bd6000
[0000000000000000] pgd=0800000111dc5003, p4d=0800000111dc5003, pud=08000001179bb003, pmd=0000000000000000
Internal error: Oops: 0000000086000006 [#1] PREEMPT SMP
Modules linked in:
CPU: 1 PID: 4288 Comm: syz-executor317 Not tainted 6.1.117-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : 0x0
lr : __lookup_slow+0x250/0x374 fs/namei.c:1690
sp : ffff800020fe7020
x29: ffff800020fe7100 x28: 0000000010000000 x27: 1fffe00019e3eb1f
x26: dfff800000000000 x25: ffff7000041fce08 x24: ffff800020fe7060
x23: ffff0000e1fe8018 x22: ffff800020fe7180 x21: ffff8000124ac440
x20: 0000000000000000 x19: ffff0000cf1f58f8 x18: ffff800020fe6b80
x17: ffff800018aab000 x16: ffff800012295aec x15: ffff80001858bf80
x14: 000000002c99bfa8 x13: dfff800000000000 x12: 0000000000000001
x11: 0000000000ff0100 x10: 0000000000000000 x9 : ffff0000d94d5340
x8 : 0000000000000000 x7 : 0000000000000000 x6 : 0000000000000000
x5 : ffff800018bdf9f8 x4 : 0000000000000001 x3 : ffff800008aa304c
x2 : 0000000000000000 x1 : ffff0000cf1f58f8 x0 : ffff0000e1fe8018
Call trace:
 0x0
 lookup_slow fs/namei.c:1707 [inline]
 lookup_one_unlocked+0x144/0x254 fs/namei.c:2801
 ovl_lookup_positive_unlocked fs/overlayfs/namei.c:207 [inline]
 ovl_lookup_single+0x110/0x8d0 fs/overlayfs/namei.c:233
 ovl_lookup_layer+0x368/0x454 fs/overlayfs/namei.c:320
 ovl_lookup+0x8f8/0x1ab4 fs/overlayfs/namei.c:923
 lookup_open fs/namei.c:3460 [inline]
 open_last_lookups fs/namei.c:3550 [inline]
 path_openat+0xd3c/0x2548 fs/namei.c:3780
 do_filp_open+0x1bc/0x3cc fs/namei.c:3810
 do_sys_openat2+0x128/0x3e0 fs/open.c:1318
 do_sys_open fs/open.c:1334 [inline]
 __do_sys_openat fs/open.c:1350 [inline]
 __se_sys_openat fs/open.c:1345 [inline]
 __arm64_sys_openat+0x1f0/0x240 fs/open.c:1345
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2bc arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140
 do_el0_svc+0x58/0x13c arch/arm64/kernel/syscall.c:204
 el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585
Code: bad PC value
---[ end trace 0000000000000000 ]---

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/11/16 22:38 linux-6.1.y 59d7b1a7104a cfe3a04a .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-1-kasan-arm64 BUG: unable to handle kernel NULL pointer dereference in lookup_one_unlocked
2024/11/16 21:55 linux-6.1.y 59d7b1a7104a cfe3a04a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 BUG: unable to handle kernel NULL pointer dereference in lookup_one_unlocked
* Struck through repros no longer work on HEAD.