audit: type=1800 audit(1589510757.106:2760): pid=24084 uid=0 auid=0 ses=4 subj=system_u:system_r:kernel_t:s0 op=collect_data cause=failed(directio) comm="syz-executor.5" name="file0" dev="sda1" ino=18232 res=0 MINIX-fs: mounting unchecked file system, running fsck is recommended minix_free_inode: bit 1 already cleared loop2: rw=0, want=6434, limit=52 audit: type=1800 audit(1589510757.296:2761): pid=24104 uid=0 auid=0 ses=4 subj=system_u:system_r:kernel_t:s0 op=collect_data cause=failed(directio) comm="syz-executor.1" name="file0" dev="sda1" ino=16478 res=0 BUG: unable to handle kernel NULL pointer dereference at 0000000000000000 Buffer I/O error on dev loop2, logical block 3216, async page read PGD 34051067 P4D 34051067 PUD 4966d067 PMD 0 Oops: 0002 [#1] PREEMPT SMP KASAN CPU: 1 PID: 24104 Comm: syz-executor.1 Not tainted 4.19.123-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+0x76c/0x1300 fs/minix/itree_common.c:191 Code: 00 00 49 8b bc 24 28 01 00 00 b9 08 00 00 00 e8 4a 40 bc ff 31 d2 be 74 01 00 00 48 c7 c7 60 4b 9c 87 49 89 c4 e8 f4 41 4e ff 49 0f ba 2c 24 02 40 0f 92 c6 31 ff 40 88 74 24 78 e8 1d f0 6e audit: type=1800 audit(1589510757.406:2762): pid=24095 uid=0 auid=0 ses=4 subj=system_u:system_r:kernel_t:s0 op=collect_data cause=failed comm="syz-executor.2" name="/" dev="loop2" ino=1 res=0 RSP: 0018:ffff888027cb7788 EFLAGS: 00010246 RAX: 0000000000000007 RBX: ffff888027cb7888 RCX: 1ffffffff1238a90 RDX: 0000000000000000 RSI: ffffffff88d929a0 RDI: ffff888027e3e724 RBP: ffff888027cb7920 R08: ffff888027e3e700 R09: fffff940000845ff R10: fffff940000845fe R11: ffffea0000422ff7 R12: 0000000000000000 R13: dffffc0000000000 R14: ffff888027cb784c R15: 0000000000000c98 FS: 00007fd234192700(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 audit: type=1800 audit(1589510757.406:2763): pid=24119 uid=0 auid=0 ses=4 subj=system_u:system_r:kernel_t:s0 op=collect_data cause=failed(directio) comm="syz-executor.5" name="file0" dev="sda1" ino=18232 res=0 CR2: 0000000000000000 CR3: 0000000028a4f000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: MINIX-fs: mounting unchecked file system, running fsck is recommended MINIX-fs: mounting unchecked file system, running fsck is recommended minix_free_inode: bit 1 already cleared minix_get_block+0xe5/0x110 fs/minix/inode.c:379 __block_write_begin_int+0x480/0x17a0 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+0x37f/0x729 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 vfs_write+0x206/0x550 fs/read_write.c:549 ksys_write+0x12b/0x2a0 fs/read_write.c:599 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c829 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:00007fd234191c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 000000000050c5e0 RCX: 000000000045c829 RDX: 0000000000004000 RSI: 0000000020000980 RDI: 0000000000000006 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000ce8 R14: 00000000004cf14a R15: 00007fd2341926d4 Modules linked in: CR2: 0000000000000000 ---[ end trace 8e972b7e2eaf72fb ]--- 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+0x76c/0x1300 fs/minix/itree_common.c:191 Code: 00 00 49 8b bc 24 28 01 00 00 b9 08 00 00 00 e8 4a 40 bc ff 31 d2 be 74 01 00 00 48 c7 c7 60 4b 9c 87 49 89 c4 e8 f4 41 4e ff 49 0f ba 2c 24 02 40 0f 92 c6 31 ff 40 88 74 24 78 e8 1d f0 6e RSP: 0018:ffff888027cb7788 EFLAGS: 00010246 RAX: 0000000000000007 RBX: ffff888027cb7888 RCX: 1ffffffff1238a90 minix_free_inode: bit 1 already cleared RDX: 0000000000000000 RSI: ffffffff88d929a0 RDI: ffff888027e3e724 minix_free_inode: bit 1 already cleared RBP: ffff888027cb7920 R08: ffff888027e3e700 R09: fffff940000845ff xt_ct_set_timeout: 36 callbacks suppressed xt_CT: No such timeout policy "syz0" R10: fffff940000845fe R11: ffffea0000422ff7 R12: 0000000000000000 R13: dffffc0000000000 R14: ffff888027cb784c R15: 0000000000000c98 FS: 00007fd234192700(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b30620000 CR3: 0000000028a4f000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400