On Sat, Apr 11, 2020 at 12:39:13AM -0700, syzbot wrote: > The bug was bisected to: > > commit d3b6f23f71670007817a5d59f3fbafab2b794e8c > Author: Ritesh Harjani <riteshh@xxxxxxxxxxxxx> > Date: Fri Feb 28 09:26:58 2020 +0000 > > ext4: move ext4_fiemap to use iomap framework > > bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=16c62a57e00000 > final crash: https://syzkaller.appspot.com/x/report.txt?x=15c62a57e00000 > console output: https://syzkaller.appspot.com/x/log.txt?x=11c62a57e00000 > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+77fa5bdb65cc39711820@xxxxxxxxxxxxxxxxxxxxxxxxx > Fixes: d3b6f23f7167 ("ext4: move ext4_fiemap to use iomap framework") > > ------------[ cut here ]------------ > WARNING: CPU: 0 PID: 7023 at fs/iomap/apply.c:51 iomap_apply+0xa0c/0xcb0 fs/iomap/apply.c:51 This is: if (WARN_ON(iomap.length == 0)) return -EIO; and the call trace contains ext4_fiemap() so the syzbot bisection looks correct. > iomap_fiemap+0x184/0x2c0 fs/iomap/fiemap.c:88 > _ext4_fiemap+0x178/0x4f0 fs/ext4/extents.c:4860 > ovl_fiemap+0x13f/0x200 fs/overlayfs/inode.c:467 > ioctl_fiemap fs/ioctl.c:226 [inline] > do_vfs_ioctl+0x8d7/0x12d0 fs/ioctl.c:715
