------------[ cut here ]------------
sb_rdonly(sb)
WARNING: fs/ext4/ext4_jbd2.c:75 at ext4_journal_check_start+0x24e/0x340 fs/ext4/ext4_jbd2.c:75, CPU#1: syz.3.415/7518
Modules linked in:
CPU: 1 UID: 0 PID: 7518 Comm: syz.3.415 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:ext4_journal_check_start+0x24e/0x340 fs/ext4/ext4_jbd2.c:75
Code: 89 d8 5b 5d 41 5c 41 5d e9 1a 03 47 fe e8 ca 2b 40 ff bb fb ff ff ff 89 d8 5b 5d 41 5c 41 5d e9 03 03 47 fe e8 b3 2b 40 ff 90 <0f> 0b 90 bb e2 ff ff ff eb c7 e8 a3 2b 40 ff 90 0f 0b 90 e9 2e ff
RSP: 0018:ffffc900048af628 EFLAGS: 00010283
RAX: 0000000000001364 RBX: ffff88802a42a000 RCX: ffffc900110a4000
RDX: 0000000000080000 RSI: ffffffff82c93e0d RDI: ffff888031671ec0
RBP: 0000000000000001 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000001 R11: 1ffff1100540d472 R12: ffff88802a42a628
R13: ffff88802a42c000 R14: 0000000000000000 R15: 0000000000000370
FS:  00007ff0faac46c0(0000) GS:ffff8881243dd000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff730825000 CR3: 0000000027026000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 __ext4_journal_start_sb+0xb0/0x670 fs/ext4/ext4_jbd2.c:107
 ext4_sample_last_mounted fs/ext4/file.c:880 [inline]
 ext4_file_open+0x863/0x10c0 fs/ext4/file.c:912
 do_dentry_open+0x6d8/0x1660 fs/open.c:947
 vfs_open+0x82/0x3f0 fs/open.c:1079
 do_open fs/namei.c:4699 [inline]
 path_openat+0x208c/0x31a0 fs/namei.c:4858
 do_file_open+0x20e/0x430 fs/namei.c:4887
 do_open_execat+0xd1/0x360 fs/exec.c:781
 open_exec+0x28/0x40 fs/exec.c:817
 bm_register_write+0x1452/0x1900 fs/binfmt_misc.c:821
 vfs_write+0x2aa/0x1070 fs/read_write.c:686
 ksys_write+0x12a/0x250 fs/read_write.c:740
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff0f9b9c819
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:00007ff0faac4028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007ff0f9e16090 RCX: 00007ff0f9b9c819
RDX: 0000000000000113 RSI: 0000200000000880 RDI: 0000000000000005
RBP: 00007ff0f9c32c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff0f9e16128 R14: 00007ff0f9e16090 R15: 00007ffc2d436928
 </TASK>