MINIX-fs: mounting unchecked file system, running fsck is recommended
==================================================================
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:367 [inline]
BUG: KASAN: null-ptr-deref in lock_buffer include/linux/buffer_head.h:373 [inline]
BUG: KASAN: null-ptr-deref in alloc_branch fs/minix/itree_common.c:88 [inline]
BUG: KASAN: null-ptr-deref in get_block+0x657/0x1380 fs/minix/itree_common.c:191
Write of size 8 at addr 0000000000000000 by task syz-executor.5/5731

CPU: 0 PID: 5731 Comm: syz-executor.5 Not tainted 5.7.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x188/0x20d lib/dump_stack.c:118
 __kasan_report.cold+0x5/0x38 mm/kasan/report.c:515
 kasan_report+0x33/0x50 mm/kasan/common.c:625
 check_memory_region_inline mm/kasan/generic.c:187 [inline]
 check_memory_region+0x141/0x190 mm/kasan/generic.c:193
 test_and_set_bit_lock include/asm-generic/bitops/instrumented-lock.h:55 [inline]
 trylock_buffer include/linux/buffer_head.h:367 [inline]
 lock_buffer include/linux/buffer_head.h:373 [inline]
 alloc_branch fs/minix/itree_common.c:88 [inline]
 get_block+0x657/0x1380 fs/minix/itree_common.c:191
 minix_get_block+0xe5/0x110 fs/minix/inode.c:376
 __block_write_begin_int+0x490/0x1b00 fs/buffer.c:2013
 __block_write_begin fs/buffer.c:2063 [inline]
 block_write_begin+0x58/0x2e0 fs/buffer.c:2122
 minix_write_begin+0x35/0xe0 fs/minix/inode.c:412
 generic_perform_write+0x20a/0x4e0 mm/filemap.c:3302
 __generic_file_write_iter+0x24c/0x610 mm/filemap.c:3431
 generic_file_write_iter+0x3f3/0x630 mm/filemap.c:3463
 call_write_iter include/linux/fs.h:1907 [inline]
 new_sync_write+0x4a2/0x700 fs/read_write.c:484
 __vfs_write+0xc9/0x100 fs/read_write.c:497
 vfs_write+0x268/0x5d0 fs/read_write.c:559
 ksys_write+0x12d/0x250 fs/read_write.c:612
 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3
RIP: 0033:0x45ca29
Code: 0d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 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 0f 83 db b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f443cc3ec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000000000050c8c0 RCX: 000000000045ca29
RDX: 0000000020000767 RSI: 0000000020000480 RDI: 0000000000000004
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000cea R14: 00000000004cf36f R15: 00007f443cc3f6d4
==================================================================