================================================================== 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+0x635/0x1380 fs/minix/itree_common.c:191 Write of size 8 at addr 0000000000000000 by task syz-executor.0/14930 CPU: 1 PID: 14930 Comm: syz-executor.0 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+0x188/0x20d lib/dump_stack.c:118 __kasan_report mm/kasan/report.c:517 [inline] kasan_report.cold+0x5/0x37 mm/kasan/report.c:530 check_memory_region_inline mm/kasan/generic.c:186 [inline] check_memory_region+0x141/0x190 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+0x635/0x1380 fs/minix/itree_common.c:191 minix_get_block+0xe5/0x110 fs/minix/inode.c:376 __block_write_begin_int+0x490/0x1b20 fs/buffer.c:2012 __block_write_begin fs/buffer.c:2062 [inline] block_write_begin+0x58/0x2e0 fs/buffer.c:2121 minix_write_begin+0x35/0xe0 fs/minix/inode.c:412 generic_perform_write+0x20a/0x4e0 mm/filemap.c:3299 __generic_file_write_iter+0x24c/0x610 mm/filemap.c:3428 generic_file_write_iter+0x3f3/0x630 mm/filemap.c:3460 call_write_iter include/linux/fs.h:1917 [inline] new_sync_write+0x426/0x650 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: 0033:0x45ca69 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:00007fdf5154ec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 000000000050d440 RCX: 000000000045ca69 RDX: 000000000000fdef RSI: 0000000020000980 RDI: 0000000000000006 RBP: 000000000078bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000d09 R14: 00000000004cf610 R15: 00007fdf5154f6d4 ==================================================================