==================================================================
BUG: KASAN: user-memory-access in scnprintf_cpu_key fs/reiserfs/prints.c:95 [inline]
BUG: KASAN: user-memory-access in prepare_error_buf+0x1288/0x1790 fs/reiserfs/prints.c:229
Read of size 4 at addr 00000000ffffffff by task syz.1.592/6967

CPU: 1 PID: 6967 Comm: syz.1.592 Not tainted 5.15.185-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call trace:
 dump_backtrace+0x0/0x43c arch/arm64/kernel/stacktrace.c:152
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:216
 __dump_stack+0x30/0x40 lib/dump_stack.c:88
 dump_stack_lvl+0xf8/0x160 lib/dump_stack.c:106
 __kasan_report mm/kasan/report.c:438 [inline]
 kasan_report+0xe0/0x15c mm/kasan/report.c:451
 __asan_report_load4_noabort+0x44/0x50 mm/kasan/report_generic.c:308
 scnprintf_cpu_key fs/reiserfs/prints.c:95 [inline]
 prepare_error_buf+0x1288/0x1790 fs/reiserfs/prints.c:229
 __reiserfs_error+0xd0/0x28c fs/reiserfs/prints.c:396
 reiserfs_do_truncate+0x3a8/0x1020 fs/reiserfs/stree.c:1930
 reiserfs_truncate_file+0x328/0x6e4 fs/reiserfs/inode.c:2318
 reiserfs_truncate_failed_write fs/reiserfs/inode.c:2751 [inline]
 reiserfs_write_begin+0x548/0x654 fs/reiserfs/inode.c:2823
 generic_perform_write+0x204/0x480 mm/filemap.c:3785
 __generic_file_write_iter+0x23c/0x454 mm/filemap.c:3912
 generic_file_write_iter+0xb0/0x1b4 mm/filemap.c:3944
 call_write_iter include/linux/fs.h:2172 [inline]
 new_sync_write fs/read_write.c:507 [inline]
 vfs_write+0x7c8/0xa2c fs/read_write.c:594
 ksys_write+0x120/0x210 fs/read_write.c:647
 __do_sys_write fs/read_write.c:659 [inline]
 __se_sys_write fs/read_write.c:656 [inline]
 __arm64_sys_write+0x7c/0x90 fs/read_write.c:656
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
 el0_svc+0x78/0x1e0 arch/arm64/kernel/entry-common.c:608
 el0t_64_sync_handler+0xcc/0xe4 arch/arm64/kernel/entry-common.c:626
 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584
==================================================================
Unable to handle kernel paging request at virtual address 00000000ffffffff
Mem abort info:
  ESR = 0x0000000096000005
  EC = 0x25: DABT (current EL), IL = 32 bits
  SET = 0, FnV = 0
  EA = 0, S1PTW = 0
  FSC = 0x05: level 1 translation fault
Data abort info:
  ISV = 0, ISS = 0x00000005
  CM = 0, WnR = 0
user pgtable: 4k pages, 48-bit VAs, pgdp=000000012eb3e000
[00000000ffffffff] pgd=080000010bf76003, p4d=080000010bf76003, pud=0000000000000000
Internal error: Oops: 0000000096000005 [#1] PREEMPT SMP
Modules linked in:
CPU: 1 PID: 6967 Comm: syz.1.592 Tainted: G    B             5.15.185-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : scnprintf_cpu_key fs/reiserfs/prints.c:95 [inline]
pc : prepare_error_buf+0x748/0x1790 fs/reiserfs/prints.c:229
lr : scnprintf_cpu_key fs/reiserfs/prints.c:95 [inline]
lr : prepare_error_buf+0x1288/0x1790 fs/reiserfs/prints.c:229
sp : ffff80001fac7200
x29: ffff80001fac7380 x28: ffff80001aede91e x27: dfff800000000000
x26: ffff80001fac7400 x25: 00000000ffffffff x24: ffff80001aedda1e
x23: 000000000000004b x22: ffff80001fac7418 x21: ffff80001fac73e0
x20: ffffffffffffffe2 x19: ffff80001447e260 x18: 0000000000000003
x17: 0000000000000002 x16: ffff8000082d4c48 x15: 00000000ffffffff
x14: 0000000000ff0100 x13: 0000000000000001 x12: 0000000000080000
x11: 000000000007ffff x10: ffff800025669000 x9 : 0000000000000000
x8 : ffff0000f4220000 x7 : 0000000000000000 x6 : 0000000000000001
x5 : ffff80001fac6a18 x4 : 0000000000000000 x3 : ffff800008184638
x2 : 0000000000000001 x1 : 0000000000000001 x0 : 00000000ffffffff
Call trace:
 scnprintf_cpu_key fs/reiserfs/prints.c:95 [inline]
 prepare_error_buf+0x748/0x1790 fs/reiserfs/prints.c:229
 __reiserfs_error+0xd0/0x28c fs/reiserfs/prints.c:396
 reiserfs_do_truncate+0x3a8/0x1020 fs/reiserfs/stree.c:1930
 reiserfs_truncate_file+0x328/0x6e4 fs/reiserfs/inode.c:2318
 reiserfs_truncate_failed_write fs/reiserfs/inode.c:2751 [inline]
 reiserfs_write_begin+0x548/0x654 fs/reiserfs/inode.c:2823
 generic_perform_write+0x204/0x480 mm/filemap.c:3785
 __generic_file_write_iter+0x23c/0x454 mm/filemap.c:3912
 generic_file_write_iter+0xb0/0x1b4 mm/filemap.c:3944
 call_write_iter include/linux/fs.h:2172 [inline]
 new_sync_write fs/read_write.c:507 [inline]
 vfs_write+0x7c8/0xa2c fs/read_write.c:594
 ksys_write+0x120/0x210 fs/read_write.c:647
 __do_sys_write fs/read_write.c:659 [inline]
 __se_sys_write fs/read_write.c:656 [inline]
 __arm64_sys_write+0x7c/0x90 fs/read_write.c:656
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
 el0_svc+0x78/0x1e0 arch/arm64/kernel/entry-common.c:608
 el0t_64_sync_handler+0xcc/0xe4 arch/arm64/kernel/entry-common.c:626
 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584
Code: d343ff28 38fb6908 35005988 aa1903e0 (b8404408) 
---[ end trace 8d2f4c45ce4f972b ]---
----------------
Code disassembly (best guess):
   0:	d343ff28 	lsr	x8, x25, #3
   4:	38fb6908 	ldrsb	w8, [x8, x27]
   8:	35005988 	cbnz	w8, 0xb38
   c:	aa1903e0 	mov	x0, x25
* 10:	b8404408 	ldr	w8, [x0], #4 <-- trapping instruction