==================================================================
BUG: KASAN: null-ptr-deref in instrument_atomic_read include/linux/instrumented.h:68 [inline]
BUG: KASAN: null-ptr-deref in _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
BUG: KASAN: null-ptr-deref in buffer_locked include/linux/buffer_head.h:126 [inline]
BUG: KASAN: null-ptr-deref in fix_nodes+0x464/0x8660 fs/reiserfs/fix_node.c:2578
Read of size 8 at addr 0000000000000000 by task syz-executor.4/21268

CPU: 1 PID: 21268 Comm: syz-executor.4 Not tainted 6.3.0-rc7-next-20230420-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/30/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106
 print_report mm/kasan/report.c:465 [inline]
 kasan_report+0xec/0x130 mm/kasan/report.c:572
 check_region_inline mm/kasan/generic.c:181 [inline]
 kasan_check_range+0x141/0x190 mm/kasan/generic.c:187
 instrument_atomic_read include/linux/instrumented.h:68 [inline]
 _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
 buffer_locked include/linux/buffer_head.h:126 [inline]
 fix_nodes+0x464/0x8660 fs/reiserfs/fix_node.c:2578
 reiserfs_cut_from_item+0x2bd/0x1b20 fs/reiserfs/stree.c:1740
 reiserfs_do_truncate+0x630/0x1080 fs/reiserfs/stree.c:1971
 reiserfs_truncate_file+0x1b5/0x1070 fs/reiserfs/inode.c:2308
 reiserfs_setattr+0xddf/0x1370 fs/reiserfs/inode.c:3393
 notify_change+0xb2c/0x1180 fs/attr.c:483
 do_truncate+0x143/0x200 fs/open.c:66
 handle_truncate fs/namei.c:3219 [inline]
 do_open fs/namei.c:3564 [inline]
 path_openat+0x2083/0x2750 fs/namei.c:3715
 do_filp_open+0x1ba/0x410 fs/namei.c:3742
 do_sys_openat2+0x16d/0x4c0 fs/open.c:1356
 do_sys_open fs/open.c:1372 [inline]
 __do_sys_creat fs/open.c:1448 [inline]
 __se_sys_creat fs/open.c:1442 [inline]
 __x64_sys_creat+0xcd/0x120 fs/open.c:1442
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f129988c169
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 90 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f129a530168 EFLAGS: 00000246 ORIG_RAX: 0000000000000055
RAX: ffffffffffffffda RBX: 00007f12999ac120 RCX: 00007f129988c169
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000000
RBP: 00007f12998e7ca1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffca3a5d66f R14: 00007f129a530300 R15: 0000000000022000
 </TASK>
==================================================================