syzbot


Unable to handle kernel write to read-only memory at virtual address ADDR

Status: upstream: reported syz repro on 2025/12/02 02:17
Reported-by: syzbot+ae1270b70f324f75ac92@syzkaller.appspotmail.com
First crash: 57d, last: 18d
Bug presence (1)
Date Name Commit Repro Result
2026/01/27 upstream (ToT) 1f97d9dcf536 syz Failed due to an error; will retry later
Similar bugs (2)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream Unable to handle kernel write to read-only memory at virtual address ADDR udf -1 C 11 1082d 1220d 0/29 auto-obsoleted due to no activity on 2023/06/11 03:59
upstream Unable to handle kernel write to read-only memory at virtual address ADDR (2) net lsm -1 1 205d 203d 29/29 fixed on 2025/09/04 16:57

Sample crash report:
Unable to handle kernel write to read-only memory at virtual address ffff0001cd4d86c8
KASAN: maybe wild-memory-access in range [0xfffc000e6a6c3640-0xfffc000e6a6c3647]
Mem abort info:
  ESR = 0x000000009600004e
  EC = 0x25: DABT (current EL), IL = 32 bits
  SET = 0, FnV = 0
  EA = 0, S1PTW = 0
  FSC = 0x0e: level 2 permission fault
Data abort info:
  ISV = 0, ISS = 0x0000004e
  CM = 0, WnR = 1
swapper pgtable: 4k pages, 48-bit VAs, pgdp=000000020e1fd000
[ffff0001cd4d86c8] pgd=180000023fffa003, p4d=180000023fffa003, pud=180000023ec11003, pmd=006000020d400781
Internal error: Oops: 000000009600004e [#1] PREEMPT SMP
Modules linked in:
CPU: 1 PID: 4417 Comm: syz-executor Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/03/2025
pstate: 62400005 (nZCv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=--)
pc : udf_close_lvid+0x134/0x780 fs/udf/super.c:2105
lr : udf_close_lvid+0x114/0x780 fs/udf/super.c:2104
sp : ffff800020ab7880
x29: ffff800020ab7900 x28: ffff0001cd4d86b0 x27: 1fffe0001b1518cf
x26: dfff800000000000 x25: ffff0000e00fe658 x24: ffff0000daa24000
x23: 1ffff00004156f14 x22: ffff0000ea1ac04b x21: ffff0000d8a8c678
x20: ffff0000ea1ac000 x19: ffff0000daa24038 x18: ffff800011a5bd40
x17: ffff800018184000 x16: ffff8000082cb864 x15: ffff800008a26150
x14: ffff8000089a2b8c x13: 1ffff00002a0a0b1 x12: 0000000000ff0100
x11: ff0080000a895d54 x10: 0000000000000001 x9 : 1fffe00039a9b0d9
x8 : 0000000000000004 x7 : ffff8000098264e4 x6 : 0000000000000000
x5 : 0000000000000000 x4 : 0000000000000001 x3 : ffff8000082cacfc
x2 : ffff0000d804d340 x1 : ffff800011f49d20 x0 : ffff0001cd4d86c9
Call trace:
 udf_close_lvid+0x134/0x780 fs/udf/super.c:2106
 udf_put_super+0xb8/0x148 fs/udf/super.c:2392
 generic_shutdown_super+0x130/0x324 fs/super.c:501
 kill_block_super+0x70/0xdc fs/super.c:1470
 deactivate_locked_super+0xac/0x124 fs/super.c:332
 deactivate_super+0xe8/0x108 fs/super.c:363
 cleanup_mnt+0x37c/0x404 fs/namespace.c:1191
 __cleanup_mnt+0x20/0x30 fs/namespace.c:1198
 task_work_run+0x1ec/0x270 kernel/task_work.c:203
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 do_notify_resume+0x2038/0x2b28 arch/arm64/kernel/signal.c:1137
 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline]
 exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline]
 el0_svc+0x98/0x138 arch/arm64/kernel/entry-common.c:638
 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: 91006780 52800088 f9000ff7 d343fc09 (39006388) 
---[ end trace 0000000000000000 ]---
----------------
Code disassembly (best guess):
   0:	91006780 	add	x0, x28, #0x19
   4:	52800088 	mov	w8, #0x4                   	// #4
   8:	f9000ff7 	str	x23, [sp, #24]
   c:	d343fc09 	lsr	x9, x0, #3
* 10:	39006388 	strb	w8, [x28, #24] <-- trapping instruction

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/01/09 20:51 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro #1] [mounted in repro #2] ci2-linux-6-1-kasan-arm64 Unable to handle kernel write to read-only memory at virtual address ADDR
2025/12/02 02:16 linux-6.1.y f6e38ae624cf d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 Unable to handle kernel write to read-only memory at virtual address ADDR
* Struck through repros no longer work on HEAD.