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BUG: KASAN: null-ptr-deref in instrument_atomic_read_write include/linux/instrumented.h:101 [inline]
BUG: KASAN: null-ptr-deref in test_and_set_bit_lock include/asm-generic/bitops/instrumented-lock.h:55 [inline]
BUG: KASAN: null-ptr-deref in trylock_buffer include/linux/buffer_head.h:395 [inline]
BUG: KASAN: null-ptr-deref in lock_buffer include/linux/buffer_head.h:401 [inline]
BUG: KASAN: null-ptr-deref in udf_getblk fs/udf/inode.c:383 [inline]
BUG: KASAN: null-ptr-deref in udf_bread+0x225/0x530 fs/udf/inode.c:1111
Write of size 8 at addr 0000000000000000 by task syz.1.443/5952

CPU: 1 PID: 5952 Comm: syz.1.443 Not tainted 5.15.189-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x230 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+0x27b/0x290 mm/kasan/generic.c:189
 instrument_atomic_read_write include/linux/instrumented.h:101 [inline]
 test_and_set_bit_lock include/asm-generic/bitops/instrumented-lock.h:55 [inline]
 trylock_buffer include/linux/buffer_head.h:395 [inline]
 lock_buffer include/linux/buffer_head.h:401 [inline]
 udf_getblk fs/udf/inode.c:383 [inline]
 udf_bread+0x225/0x530 fs/udf/inode.c:1111
 udf_fiiter_append_blk+0x353/0x850 fs/udf/directory.c:463
 udf_fiiter_add_entry+0x1279/0x1b60 fs/udf/namei.c:292
 udf_add_nondir+0xf1/0x2d0 fs/udf/namei.c:346
 udf_symlink+0xfd5/0x1320 fs/udf/namei.c:702
 vfs_symlink+0x247/0x3d0 fs/namei.c:4429
 do_symlinkat+0x1be/0x6c0 fs/namei.c:4458
 __do_sys_symlink fs/namei.c:4480 [inline]
 __se_sys_symlink fs/namei.c:4478 [inline]
 __x64_sys_symlink+0x7a/0x90 fs/namei.c:4478
 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: 0033:0x7fbaf0f5bbe9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fbaef1a2038 EFLAGS: 00000246 ORIG_RAX: 0000000000000058
RAX: ffffffffffffffda RBX: 00007fbaf1183090 RCX: 00007fbaf0f5bbe9
RDX: 0000000000000000 RSI: 0000200000000f40 RDI: 0000200000000180
RBP: 00007fbaf0fdee19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fbaf1183128 R14: 00007fbaf1183090 R15: 00007ffe53510788
 </TASK>
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