------------[ cut here ]------------
sb_rdonly(sb)
WARNING: fs/ext4/ext4_jbd2.c:83 at ext4_journal_check_start+0x24f/0x2b0, CPU#1: syz.1.508/7917
Modules linked in:
CPU: 1 UID: 0 PID: 7917 Comm: syz.1.508 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:ext4_journal_check_start+0x24f/0x2b0
Code: 5b 41 5c 41 5d 41 5e 41 5f 5d e9 3c cd 5d 09 cc e8 46 bb 3e ff 41 bf fb ff ff ff eb e0 e8 39 bb 3e ff eb d3 e8 32 bb 3e ff 90 <0f> 0b 90 eb c8 e8 27 bb 3e ff 90 0f 0b 90 43 80 7c 25 00 00 0f 85
RSP: 0018:ffffc9000804f5b0 EFLAGS: 00010293
RAX: ffffffff8288fb7e RBX: ffff8881a27da000 RCX: ffff88810a4fbc00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: 0000000000000001 R08: ffff88816867e40f R09: 1ffff1102d0cfc81
R10: dffffc0000000000 R11: ffffed102d0cfc82 R12: dffffc0000000000
R13: 1ffff110344fb4cf R14: ffff8881a27da678 R15: 0000000000000001
FS:  00007ff2c9fae6c0(0000) GS:ffff8882a8cda000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff2c91eb840 CR3: 00000001a7cd0000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 __ext4_journal_start_sb+0x14b/0x780
 __ext4_new_inode+0x130b/0x3ec0
 ext4_mkdir+0x3ee/0xce0
 vfs_mkdir+0x40c/0x620
 cachefiles_get_directory+0x23c/0xa30
 cachefiles_add_cache+0xb06/0xde0
 cachefiles_daemon_write+0x605/0x6c0
 vfs_write+0x296/0xba0
 ksys_write+0x150/0x270
 do_syscall_64+0x166/0x520
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff2c919e159
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 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 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ff2c9fae028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007ff2c9426180 RCX: 00007ff2c919e159
RDX: 0000000000000004 RSI: 0000200000000700 RDI: 0000000000000005
RBP: 00007ff2c923506b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff2c9426218 R14: 00007ff2c9426180 R15: 00007ffcf8376768
 </TASK>
