EXT4-fs error (device loop4): __ext4_ext_dirty:206: inode #2: comm syz.4.175: mark_inode_dirty error
Unable to handle kernel paging request at virtual address ffffffffffffff93
KASAN: maybe wild-memory-access in range [0x0003fffffffffc98-0x0003fffffffffc9f]
Mem abort info:
  ESR = 0x0000000096000004
  EC = 0x25: DABT (current EL), IL = 32 bits
  SET = 0, FnV = 0
  EA = 0, S1PTW = 0
  FSC = 0x04: level 0 translation fault
Data abort info:
  ISV = 0, ISS = 0x00000004
  CM = 0, WnR = 0
swapper pgtable: 4k pages, 48-bit VAs, pgdp=000000020dfcc000
[ffffffffffffff93] pgd=0000000000000000, p4d=0000000000000000
Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
Modules linked in:
CPU: 1 PID: 4968 Comm: syz.4.175 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/26/2026
pstate: 62400005 (nZCv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=--)
pc : ext4_ext_drop_refs fs/ext4/extents.c:119 [inline]
pc : ext4_free_ext_path fs/ext4/extents.c:128 [inline]
pc : ext4_ext_map_blocks+0x2a70/0x570c fs/ext4/extents.c:4497
lr : ext4_ext_map_blocks+0x1528/0x570c fs/ext4/extents.c:4438
sp : ffff800020d672c0
x29: ffff800020d67540 x28: dfff800000000000 x27: 0000000000000001
x26: ffff800020d67780 x25: 0000000000000001 x24: 0000000000000001
x23: 0000000000000001 x22: 0000000000000002 x21: 0000000000000015
x20: ffff800020d67780 x19: ffffffffffffff8b x18: ffff800011b9bf60
x17: 0000000000000000 x16: ffff8000082d7db8 x15: 0000000000000002
x14: 0000000000000001 x13: 1fffe0001c1eb911 x12: 0000000000080000
x11: 000000000005d289 x10: ffff80002d3cd000 x9 : 19a53a73a1b09d00
x8 : 0000000000000000 x7 : ffff8000089375f0 x6 : 0000000000000000
x5 : 0000000000000080 x4 : ffff0000dddfe2b8 x3 : ffff800008a90998
x2 : 0000000000000001 x1 : 0000000000000000 x0 : ffffffffffffff93
Call trace:
 ext4_ext_drop_refs fs/ext4/extents.c:119 [inline]
 ext4_free_ext_path fs/ext4/extents.c:128 [inline]
 ext4_ext_map_blocks+0x2a70/0x570c fs/ext4/extents.c:4497
 ext4_map_blocks+0x860/0x1778 fs/ext4/inode.c:679
 ext4_getblk+0x178/0x664 fs/ext4/inode.c:890
 ext4_bread+0x3c/0x1a8 fs/ext4/inode.c:946
 ext4_append+0x248/0x498 fs/ext4/namei.c:83
 ext4_add_entry+0x780/0xbc8 fs/ext4/namei.c:2511
 ext4_mkdir+0x430/0xa1c fs/ext4/namei.c:3081
 vfs_mkdir+0x314/0x4d4 fs/namei.c:4114
 do_mkdirat+0x1b8/0x3ec fs/namei.c:4139
 __do_sys_mkdirat fs/namei.c:4154 [inline]
 __se_sys_mkdirat fs/namei.c:4152 [inline]
 __arm64_sys_mkdirat+0x90/0xa8 fs/namei.c:4152
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2b4 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: 2a1803fb d343fc08 38fc6908 35006ba8 (79401276) 
---[ end trace 0000000000000000 ]---
----------------
Code disassembly (best guess):
   0:	2a1803fb 	mov	w27, w24
   4:	d343fc08 	lsr	x8, x0, #3
   8:	38fc6908 	ldrsb	w8, [x8, x28]
   c:	35006ba8 	cbnz	w8, 0xd80
* 10:	79401276 	ldrh	w22, [x19, #8] <-- trapping instruction