audit: type=1800 audit(1591127488.494:117): pid=11594 uid=0 auid=0 ses=4 subj=system_u:system_r:kernel_t:s0 op=collect_data cause=failed(directio) comm="syz-executor.0" name="file0" dev="sda1" ino=16243 res=0 MINIX-fs: mounting unchecked file system, running fsck is recommended BUG: unable to handle kernel NULL pointer dereference at 0000000000000000 PGD 8ab4b067 P4D 8ab4b067 PUD 967a2067 PMD 0 Oops: 0002 [#1] PREEMPT SMP KASAN CPU: 1 PID: 11594 Comm: syz-executor.0 Not tainted 4.19.125-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:test_and_set_bit arch/x86/include/asm/bitops.h:209 [inline] RIP: 0010:test_and_set_bit_lock arch/x86/include/asm/bitops.h:223 [inline] RIP: 0010:trylock_buffer include/linux/buffer_head.h:367 [inline] RIP: 0010:lock_buffer include/linux/buffer_head.h:373 [inline] RIP: 0010:alloc_branch fs/minix/itree_common.c:88 [inline] RIP: 0010:get_block+0x772/0x1320 fs/minix/itree_common.c:191 Code: 00 00 49 8b bc 24 28 01 00 00 b9 08 00 00 00 e8 c4 b7 bc ff 31 d2 be 74 01 00 00 48 c7 c7 e0 3d 7c 87 49 89 c4 e8 ae da 4d ff 49 0f ba 2c 24 02 40 0f 92 c6 31 ff 40 88 74 24 78 e8 07 38 6f RSP: 0018:ffff888049537210 EFLAGS: 00010246 RAX: 0000000000000007 RBX: 0000000000000c98 RCX: 1ffffffff11f89b8 RDX: 0000000000000000 RSI: 00000000ffffffff RDI: ffff888087280264 RBP: ffff8880495373a8 R08: ffff888087280240 R09: fffff94000241127 R10: fffff94000241126 R11: ffffea0001208937 R12: 0000000000000000 R13: dffffc0000000000 R14: ffff8880495372d4 R15: ffff888049537310 FS: 00007f7f2e47b700(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000009f675000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: minix_get_block+0xe5/0x110 fs/minix/inode.c:379 __block_write_begin_int+0x47d/0x1770 fs/buffer.c:1978 __block_write_begin fs/buffer.c:2028 [inline] block_write_begin+0x58/0x2e0 fs/buffer.c:2087 minix_write_begin+0x35/0xe0 fs/minix/inode.c:415 generic_perform_write+0x1f8/0x4d0 mm/filemap.c:3162 __generic_file_write_iter+0x24c/0x610 mm/filemap.c:3287 generic_file_write_iter+0x3f4/0x725 mm/filemap.c:3315 call_write_iter include/linux/fs.h:1821 [inline] new_sync_write fs/read_write.c:474 [inline] __vfs_write+0x512/0x760 fs/read_write.c:487 __kernel_write+0x109/0x370 fs/read_write.c:506 write_pipe_buf+0x153/0x1e0 fs/splice.c:798 splice_from_pipe_feed fs/splice.c:503 [inline] __splice_from_pipe+0x38f/0x7a0 fs/splice.c:627 splice_from_pipe+0xd9/0x140 fs/splice.c:662 default_file_splice_write+0x37/0x90 fs/splice.c:810 do_splice_from fs/splice.c:852 [inline] direct_splice_actor+0x115/0x160 fs/splice.c:1025 splice_direct_to_actor+0x33f/0x8d0 fs/splice.c:980 do_splice_direct+0x1a8/0x270 fs/splice.c:1068 do_sendfile+0x549/0xc10 fs/read_write.c:1447 __do_sys_sendfile64 fs/read_write.c:1502 [inline] __se_sys_sendfile64+0xc4/0x160 fs/read_write.c:1494 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe 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:00007f7f2e47ac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00000000004fc580 RCX: 000000000045ca69 RDX: 0000000020000480 RSI: 0000000000000004 RDI: 0000000000000004 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000000a198 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000008dc R14: 00000000004cba56 R15: 00007f7f2e47b6d4 Modules linked in: CR2: 0000000000000000 audit: type=1800 audit(1591127489.165:118): pid=11609 uid=0 auid=0 ses=4 subj=system_u:system_r:kernel_t:s0 op=collect_data cause=failed(directio) comm="syz-executor.2" name="file0" dev="sda1" ino=15781 res=0 audit: type=1800 audit(1591127489.415:119): pid=11626 uid=0 auid=0 ses=4 subj=system_u:system_r:kernel_t:s0 op=collect_data cause=failed(directio) comm="syz-executor.2" name="file0" dev="sda1" ino=16250 res=0 ---[ end trace 07bbd63d9c33e93c ]--- RIP: 0010:test_and_set_bit arch/x86/include/asm/bitops.h:209 [inline] RIP: 0010:test_and_set_bit_lock arch/x86/include/asm/bitops.h:223 [inline] RIP: 0010:trylock_buffer include/linux/buffer_head.h:367 [inline] RIP: 0010:lock_buffer include/linux/buffer_head.h:373 [inline] RIP: 0010:alloc_branch fs/minix/itree_common.c:88 [inline] RIP: 0010:get_block+0x772/0x1320 fs/minix/itree_common.c:191 Code: 00 00 49 8b bc 24 28 01 00 00 b9 08 00 00 00 e8 c4 b7 bc ff 31 d2 be 74 01 00 00 48 c7 c7 e0 3d 7c 87 49 89 c4 e8 ae da 4d ff 49 0f ba 2c 24 02 40 0f 92 c6 31 ff 40 88 74 24 78 e8 07 38 6f RSP: 0018:ffff888049537210 EFLAGS: 00010246 RAX: 0000000000000007 RBX: 0000000000000c98 RCX: 1ffffffff11f89b8 RDX: 0000000000000000 RSI: 00000000ffffffff RDI: ffff888087280264 RBP: ffff8880495373a8 R08: ffff888087280240 R09: fffff94000241127 R10: fffff94000241126 R11: ffffea0001208937 R12: 0000000000000000 R13: dffffc0000000000 R14: ffff8880495372d4 R15: ffff888049537310 FS: 00007f7f2e47b700(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000400200 CR3: 000000009f675000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400