This is: WARN_ON_ONCE(iter->iomap.offset > iter->pos); so it looks like ext4 has an issue in its ->iomap_begin implementation On Mon, Nov 08, 2021 at 03:46:27PM -0800, syzbot wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: 7ddb58cb0eca Merge tag 'clk-for-linus' of git://git.kernel.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=13443b82b00000 > kernel config: https://syzkaller.appspot.com/x/.config?x=a30ce238f371e547 > dashboard link: https://syzkaller.appspot.com/bug?extid=a8e049cd3abd342936b6 > compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 > userspace arch: i386 > > Unfortunately, I don't have any reproducer for this issue yet. > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+a8e049cd3abd342936b6@xxxxxxxxxxxxxxxxxxxxxxxxx > > ------------[ cut here ]------------ > WARNING: CPU: 0 PID: 1112 at fs/iomap/iter.c:33 iomap_iter_done fs/iomap/iter.c:33 [inline] > WARNING: CPU: 0 PID: 1112 at fs/iomap/iter.c:33 iomap_iter+0xdcf/0x11b0 fs/iomap/iter.c:78 > Modules linked in: > CPU: 0 PID: 1112 Comm: kworker/u4:5 Not tainted 5.15.0-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > Workqueue: loop0 loop_rootcg_workfn > RIP: 0010:iomap_iter_done fs/iomap/iter.c:33 [inline] > RIP: 0010:iomap_iter+0xdcf/0x11b0 fs/iomap/iter.c:78 > Code: fd ff ff e8 93 9f d1 ff e9 f9 f9 ff ff e8 79 24 8b ff 0f 0b e9 85 f8 ff ff e8 6d 24 8b ff 0f 0b e9 96 f7 ff ff e8 61 24 8b ff <0f> 0b e9 f8 f6 ff ff e8 55 24 8b ff 0f 0b 48 b8 00 00 00 00 00 fc > RSP: 0018:ffffc90004d4f680 EFLAGS: 00010293 > RAX: 0000000000000000 RBX: ffffc90004d4f818 RCX: 0000000000000000 > RDX: ffff88801c181d00 RSI: ffffffff81ec9faf RDI: 0000000000000003 > RBP: ffffc90004d4f848 R08: 00000fff80000000 R09: 000000000000000c > R10: ffffffff81ec96a0 R11: 000000000000003f R12: ffffc90004d4f820 > R13: ffffffff80000000 R14: ffffc90004d4f840 R15: ffffc90004d4f888 > FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00007fc3d2148008 CR3: 00000000307d5000 CR4: 00000000003506f0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > <TASK> > __iomap_dio_rw+0x6b2/0x1a10 fs/iomap/direct-io.c:588 > iomap_dio_rw+0x38/0x90 fs/iomap/direct-io.c:679 > ext4_dio_read_iter fs/ext4/file.c:77 [inline] > ext4_file_read_iter+0x41c/0x5d0 fs/ext4/file.c:128 > call_read_iter include/linux/fs.h:2155 [inline] > lo_rw_aio.isra.0+0xa99/0xc90 drivers/block/loop.c:453 > do_req_filebacked drivers/block/loop.c:497 [inline] > loop_handle_cmd drivers/block/loop.c:1857 [inline] > loop_process_work+0x92f/0x1db0 drivers/block/loop.c:1897 > process_one_work+0x9b2/0x1690 kernel/workqueue.c:2298 > worker_thread+0x658/0x11f0 kernel/workqueue.c:2445 > kthread+0x405/0x4f0 kernel/kthread.c:327 > ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 > </TASK> > > > --- > This report is generated by a bot. It may contain errors. > See https://goo.gl/tpsmEJ for more information about syzbot. > syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. > > syzbot will keep track of this issue. See: > https://goo.gl/tpsmEJ#status for how to communicate with syzbot. ---end quoted text---
