syzbot


general protection fault in ext4_acquire_dquot

Status: upstream: reported C repro on 2023/05/12 13:15
Labels: ext4 (incorrect?)
Reported-by: syzbot+e633c79ceaecbf479854@syzkaller.appspotmail.com
First crash: 25d, last: 24d
Discussions (2)
Title Replies (including bot) Last reply
[PATCH 1/2] quota: fix null-ptr-deref in ext4_acquire_dquot() 2 (2) 2023/05/30 09:57
[syzbot] [ext4?] general protection fault in ext4_acquire_dquot 0 (1) 2023/05/12 13:15
Similar bugs (3)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-6-1 general protection fault in ext4_acquire_dquot origin:lts C done 1 9d12h 9d12h 0/2 upstream: reported C repro on 2023/05/24 09:33
android-5-15 general protection fault in ext4_acquire_dquot origin:lts C done 2 9d12h 9d12h 0/2 upstream: reported C repro on 2023/05/24 09:18
linux-5.15 BUG: unable to handle kernel paging request in ext4_acquire_dquot origin:lts-only C 1 16d 19d 0/3 upstream: reported C repro on 2023/05/14 21:50
Last patch testing requests (1)
Created Duration User Patch Repo Result
2023/05/12 19:26 24m tytso@mit.edu https://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4.git test OK log

Sample crash report:
Unable to handle kernel paging request at virtual address dfff800000000005
KASAN: null-ptr-deref in range [0x0000000000000028-0x000000000000002f]
Mem abort info:
  ESR = 0x0000000096000006
  EC = 0x25: DABT (current EL), IL = 32 bits
  SET = 0, FnV = 0
  EA = 0, S1PTW = 0
  FSC = 0x06: level 2 translation fault
Data abort info:
  ISV = 0, ISS = 0x00000006
  CM = 0, WnR = 0
[dfff800000000005] address between user and kernel address ranges
Internal error: Oops: 0000000096000006 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 6080 Comm: syz-executor747 Not tainted 6.3.0-rc7-syzkaller-g14f8db1c0f9a #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023
pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : ext4_acquire_dquot+0x1d4/0x398 fs/ext4/super.c:6766
lr : dquot_to_inode fs/ext4/super.c:6740 [inline]
lr : ext4_acquire_dquot+0x1ac/0x398 fs/ext4/super.c:6766
sp : ffff80001eb27280
x29: ffff80001eb27280 x28: 1fffe0001c3c01fc x27: ffff800015d705b0
x26: ffff0000dd93c000 x25: ffff0000dd93e000 x24: 1fffe0001c3c021c
x23: dfff800000000000 x22: 0000000000000049 x21: 0000000000000028
x20: 0000000000000000 x19: ffff0000e1e00fc0 x18: ffff0001b426cca8
x17: 0000000000000000 x16: ffff8000089669b0 x15: 0000000000000001
x14: 1ffff00002bae0b0 x13: dfff800000000000 x12: 0000000000000001
x11: 0000000000000000 x10: 0000000000000000 x9 : 0000000000000000
x8 : 0000000000000005 x7 : ffff800008c11f68 x6 : 0000000000000000
x5 : 0000000000000000 x4 : 0000000000000001 x3 : ffff800012441b4c
x2 : 0000000000000001 x1 : 0000000000000001 x0 : 0000000000000003
Call trace:
 ext4_acquire_dquot+0x1d4/0x398 fs/ext4/super.c:6766
 dqget+0x844/0xc48 fs/quota/dquot.c:914
 __dquot_initialize+0x2cc/0xb54 fs/quota/dquot.c:1492
 dquot_initialize fs/quota/dquot.c:1550 [inline]
 dquot_file_open+0x90/0xc8 fs/quota/dquot.c:2181
 ext4_file_open+0x230/0x590 fs/ext4/file.c:903
 do_dentry_open+0x724/0xf90 fs/open.c:920
 vfs_open+0x7c/0x90 fs/open.c:1051
 do_open fs/namei.c:3560 [inline]
 path_openat+0x1f2c/0x27f8 fs/namei.c:3715
 do_filp_open+0x1bc/0x3cc fs/namei.c:3742
 do_sys_openat2+0x128/0x3d8 fs/open.c:1348
 do_sys_open fs/open.c:1364 [inline]
 __do_sys_openat fs/open.c:1380 [inline]
 __se_sys_openat fs/open.c:1375 [inline]
 __arm64_sys_openat+0x1f0/0x240 fs/open.c:1375
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x64/0x198 arch/arm64/kernel/syscall.c:193
 el0_svc+0x4c/0x15c arch/arm64/kernel/entry-common.c:637
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:591
Code: 97e8a7df f94002a8 9100a115 d343fea8 (38776908) 
---[ end trace 0000000000000000 ]---
----------------
Code disassembly (best guess):
   0:	97e8a7df 	bl	0xffffffffffa29f7c
   4:	f94002a8 	ldr	x8, [x21]
   8:	9100a115 	add	x21, x8, #0x28
   c:	d343fea8 	lsr	x8, x21, #3
* 10:	38776908 	ldrb	w8, [x8, x23] <-- trapping instruction

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets Manager Title
2023/05/09 18:07 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 14f8db1c0f9a 30aa2a7e .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci-upstream-gce-arm64 BUG: unable to handle kernel paging request in ext4_acquire_dquot
2023/05/08 13:05 upstream ac9a78681b92 90c93c40 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs general protection fault in ext4_acquire_dquot
* Struck through repros no longer work on HEAD.