================================================================== 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:359 [inline] BUG: KASAN: null-ptr-deref in lock_buffer include/linux/buffer_head.h:365 [inline] BUG: KASAN: null-ptr-deref in alloc_branch fs/minix/itree_common.c:88 [inline] BUG: KASAN: null-ptr-deref in get_block+0x916/0x1600 fs/minix/itree_common.c:191 Write of size 8 at addr 0000000000000000 by task syz-executor.3/24401 CPU: 1 PID: 24401 Comm: syz-executor.3 Not tainted 5.7.0-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+0x1e9/0x30e lib/dump_stack.c:118 __kasan_report mm/kasan/report.c:517 [inline] kasan_report+0x151/0x1d0 mm/kasan/report.c:530 check_memory_region_inline mm/kasan/generic.c:183 [inline] check_memory_region+0x2b5/0x2f0 mm/kasan/generic.c:192 test_and_set_bit_lock include/asm-generic/bitops/instrumented-lock.h:55 [inline] trylock_buffer include/linux/buffer_head.h:359 [inline] lock_buffer include/linux/buffer_head.h:365 [inline] alloc_branch fs/minix/itree_common.c:88 [inline] get_block+0x916/0x1600 fs/minix/itree_common.c:191 __block_write_begin_int+0x708/0x1a00 fs/buffer.c:2012 __block_write_begin fs/buffer.c:2062 [inline] block_write_begin+0x59/0x280 fs/buffer.c:2121 minix_write_begin+0x38/0x1f0 fs/minix/inode.c:412 generic_perform_write+0x23b/0x4e0 mm/filemap.c:3299 __generic_file_write_iter+0x22b/0x4e0 mm/filemap.c:3428 generic_file_write_iter+0x4a6/0x650 mm/filemap.c:3460 call_write_iter include/linux/fs.h:1917 [inline] new_sync_write fs/read_write.c:484 [inline] __vfs_write+0x52f/0x6e0 fs/read_write.c:497 vfs_write+0x274/0x580 fs/read_write.c:559 ksys_write+0x11b/0x220 fs/read_write.c:612 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x45ca69 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:00007faa07ab0c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 000000000050cb00 RCX: 000000000045ca69 RDX: 000000000d4ba0ff RSI: 00000000200009c0 RDI: 0000000000000005 RBP: 000000000078c180 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000cf2 R14: 00000000004cf43e R15: 00007faa07ab16d4 ==================================================================