syzbot


BUG: unable to handle kernel paging request in __ext4_journal_get_write_access

Status: upstream: reported syz repro on 2026/06/16 08:34
Reported-by: syzbot+87233ebfcc370afd53d0@syzkaller.appspotmail.com
First crash: 3d11h, last: 3d11h
Similar bugs (6)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 general protection fault in __ext4_journal_get_write_access (2) 2 1 499d 499d 0/3 auto-obsoleted due to no activity on 2025/05/16 06:11
linux-6.1 general protection fault in __ext4_journal_get_write_access 2 2 642d 645d 0/3 auto-obsoleted due to no activity on 2024/12/24 15:34
linux-6.1 general protection fault in __ext4_journal_get_write_access (5) 2 1 104d 104d 0/3 auto-obsoleted due to no activity on 2026/06/15 01:27
android-6-1 general protection fault in __ext4_journal_get_write_access missing-backport origin:lts 2 C error 99 23d 256d 0/2 upstream: reported C repro on 2025/10/06 16:02
linux-6.1 general protection fault in __ext4_journal_get_write_access (3) 2 1 333d 333d 0/3 auto-obsoleted due to no activity on 2025/10/29 07:49
linux-6.1 general protection fault in __ext4_journal_get_write_access (4) 2 1 205d 205d 0/3 auto-obsoleted due to no activity on 2026/03/06 15:43

Sample crash report:
EXT4-fs (loop0): mounted filesystem without journal. Quota mode: none.
Unable to handle kernel paging request at virtual address dfff800000000007
KASAN: null-ptr-deref in range [0x0000000000000038-0x000000000000003f]
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
[dfff800000000007] address between user and kernel address ranges
Internal error: Oops: 0000000096000006 [#1] PREEMPT SMP
Modules linked in:
CPU: 1 PID: 4555 Comm: syz.0.25 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/02/2026
pstate: 62400005 (nZCv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=--)
pc : __ext4_journal_get_write_access+0xc4/0x610 fs/ext4/ext4_jbd2.c:231
lr : __ext4_journal_get_write_access+0xa0/0x610 fs/ext4/ext4_jbd2.c:229
sp : ffff800021107560
x29: ffff8000211075e0 x28: dfff800000000000 x27: ffff0000d01ce000
x26: ffff700004220eb0 x25: 0000000000000038 x24: ffff0000d01ce068
x23: 0000000000000001 x22: ffff800021107580 x21: ffff0000cff4e000
x20: 0000000000000001 x19: ffff0000e06eb0e8 x18: ffff800011babf60
x17: 1fffe00033e9f77e x16: ffff8000082d8944 x15: ffff80001523d000
x14: 0000000000000001 x13: 1fffe0001a039c82 x12: 0000000000ff0100
x11: ff0080000a8e1dfc x10: 0000000000000000 x9 : 0000000000000000
x8 : 0000000000000007 x7 : ffff800008258510 x6 : 0000000000000000
x5 : 0000000000000001 x4 : ffff0000e06eb0e8 x3 : ffff0000cff4e000
x2 : 0000000000000000 x1 : ffff800011baebc0 x0 : 0000000000000000
Call trace:
 __ext4_journal_get_write_access+0xc4/0x610 fs/ext4/ext4_jbd2.c:231
 ext4_update_primary_sb fs/ext4/ioctl.c:67 [inline]
 ext4_update_superblocks_fn+0x248/0xee8 fs/ext4/ioctl.c:221
 ext4_update_overhead+0x128/0x15c fs/ext4/ioctl.c:1712
 ext4_fill_super+0x23ec/0x61b0 fs/ext4/super.c:5712
 get_tree_bdev+0x358/0x544 fs/super.c:1366
 ext4_get_tree+0x28/0x38 fs/ext4/super.c:5723
 vfs_get_tree+0x90/0x274 fs/super.c:1573
 do_new_mount+0x228/0x810 fs/namespace.c:3078
 path_mount+0x5bc/0xe80 fs/namespace.c:3408
 do_mount fs/namespace.c:3421 [inline]
 __do_sys_mount fs/namespace.c:3629 [inline]
 __se_sys_mount fs/namespace.c:3606 [inline]
 __arm64_sys_mount+0x49c/0x59c fs/namespace.c:3606
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x290 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140
 do_el0_svc+0x58/0x130 arch/arm64/kernel/syscall.c:204
 el0_svc+0x58/0x128 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: 97ef46cb f9400328 9100e119 d343ff28 (387c6908) 
---[ end trace 0000000000000000 ]---
----------------
Code disassembly (best guess):
   0:	97ef46cb 	bl	0xffffffffffbd1b2c
   4:	f9400328 	ldr	x8, [x25]
   8:	9100e119 	add	x25, x8, #0x38
   c:	d343ff28 	lsr	x8, x25, #3
* 10:	387c6908 	ldrb	w8, [x8, x28] <-- trapping instruction

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/06/16 08:33 linux-6.1.y 228da13e907e 50bb0618 .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-6-1-kasan-arm64 BUG: unable to handle kernel paging request in __ext4_journal_get_write_access
* Struck through repros no longer work on HEAD.