RBP: 00007ffec335d220 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007fdcb4b07fac R14: 00007fdcb4b07fa0 R15: 00007fdcb4b07fa0
 </TASK>
==================================================================
BUG: KASAN: null-ptr-deref in xlog_cil_alloc_shadow_bufs fs/xfs/xfs_log_cil.c:225 [inline]
BUG: KASAN: null-ptr-deref in xlog_cil_commit+0x2d8/0x2050 fs/xfs/xfs_log_cil.c:1264
Write of size 88 at addr 0000000000000000 by task syz.0.17/4401

CPU: 0 PID: 4401 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 __kasan_report mm/kasan/report.c:438 [inline]
 kasan_report+0xd5/0x130 mm/kasan/report.c:451
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x235/0x290 mm/kasan/generic.c:189
 memset+0x1e/0x40 mm/kasan/shadow.c:44
 xlog_cil_alloc_shadow_bufs fs/xfs/xfs_log_cil.c:225 [inline]
 xlog_cil_commit+0x2d8/0x2050 fs/xfs/xfs_log_cil.c:1264
 __xfs_trans_commit+0x6b4/0xc60 fs/xfs/xfs_trans.c:881
 xfs_vn_update_time+0x3a0/0x520 fs/xfs/xfs_iops.c:1072
 inode_update_time fs/inode.c:1893 [inline]
 file_update_time+0x3a6/0x440 fs/inode.c:2083
 __xfs_filemap_fault+0x2fc/0x8f0 fs/xfs/xfs_file.c:1329
 do_page_mkwrite+0x168/0x3c0 mm/memory.c:2922
 wp_page_shared+0x16b/0x6d0 mm/memory.c:3259
 handle_pte_fault mm/memory.c:4668 [inline]
 __handle_mm_fault mm/memory.c:4785 [inline]
 handle_mm_fault+0x1f06/0x4410 mm/memory.c:4883
 do_user_addr_fault+0x489/0xc80 arch/x86/mm/fault.c:1355
 handle_page_fault arch/x86/mm/fault.c:1443 [inline]
 exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1496
 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:606
RIP: 0010:copy_user_enhanced_fast_string+0xe/0x40 arch/x86/lib/copy_user_64.S:206
Code: 89 d1 c1 e9 03 83 e2 07 f3 48 a5 89 d1 f3 a4 31 c0 0f 01 ca c3 90 90 90 90 90 90 90 0f 01 cb 83 fa 40 0f 82 70 ff ff ff 89 d1 <f3> a4 31 c0 0f 01 ca c3 90 90 90 90 90 90 90 90 90 90 89 d1 83 f8
RSP: 0018:ffffc9000304fb38 EFLAGS: 00050246
RAX: ffffffff83e1a101 RBX: 0000000000000040 RCX: 0000000000000040
RDX: 0000000000000040 RSI: ffffc9000304fd40 RDI: 0000200000000240
RBP: ffffc9000304fc90 R08: ffffc9000304fd7f R09: 1ffff92000609faf
R10: dffffc0000000000 R11: fffff52000609fb0 R12: ffffc9000304fd40
R13: dffffc00000000ff R14: 0000200000000240 R15: 0000000000000000
 copy_user_generic arch/x86/include/asm/uaccess_64.h:37 [inline]
 raw_copy_to_user arch/x86/include/asm/uaccess_64.h:58 [inline]
 copyout lib/iov_iter.c:157 [inline]
 _copy_to_iter+0x318/0x1180 lib/iov_iter.c:669
 copy_to_iter include/linux/uio.h:155 [inline]
 get_random_bytes_user+0x1cc/0x3d0 drivers/char/random.c:474
 __do_sys_getrandom drivers/char/random.c:1242 [inline]
 __se_sys_getrandom drivers/char/random.c:1215 [inline]
 __x64_sys_getrandom+0x1c2/0x2a0 drivers/char/random.c:1215
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fdcb488e799
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffec335d1b8 EFLAGS: 00000246 ORIG_RAX: 000000000000013e
RAX: ffffffffffffffda RBX: 00007fdcb4b07fa0 RCX: 00007fdcb488e799
RDX: 0000000000000000 RSI: 00000000ffffff9a RDI: 0000200000000240
RBP: 00007ffec335d220 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007fdcb4b07fac R14: 00007fdcb4b07fa0 R15: 00007fdcb4b07fa0
 </TASK>
==================================================================
----------------
Code disassembly (best guess):
   0:	89 d1                	mov    %edx,%ecx
   2:	c1 e9 03             	shr    $0x3,%ecx
   5:	83 e2 07             	and    $0x7,%edx
   8:	f3 48 a5             	rep movsq %ds:(%rsi),%es:(%rdi)
   b:	89 d1                	mov    %edx,%ecx
   d:	f3 a4                	rep movsb %ds:(%rsi),%es:(%rdi)
   f:	31 c0                	xor    %eax,%eax
  11:	0f 01 ca             	clac
  14:	c3                   	ret
  15:	90                   	nop
  16:	90                   	nop
  17:	90                   	nop
  18:	90                   	nop
  19:	90                   	nop
  1a:	90                   	nop
  1b:	90                   	nop
  1c:	0f 01 cb             	stac
  1f:	83 fa 40             	cmp    $0x40,%edx
  22:	0f 82 70 ff ff ff    	jb     0xffffff98
  28:	89 d1                	mov    %edx,%ecx
* 2a:	f3 a4                	rep movsb %ds:(%rsi),%es:(%rdi) <-- trapping instruction
  2c:	31 c0                	xor    %eax,%eax
  2e:	0f 01 ca             	clac
  31:	c3                   	ret
  32:	90                   	nop
  33:	90                   	nop
  34:	90                   	nop
  35:	90                   	nop
  36:	90                   	nop
  37:	90                   	nop
  38:	90                   	nop
  39:	90                   	nop
  3a:	90                   	nop
  3b:	90                   	nop
  3c:	89 d1                	mov    %edx,%ecx
  3e:	83                   	.byte 0x83
  3f:	f8                   	clc