Hello, syzbot found the following crash on: HEAD commit: b85051e7 Merge tag 'fixes-for-5.7-rc6' of git://git.kernel.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=165d2b81100000 kernel config: https://syzkaller.appspot.com/x/.config?x=b3368ce0cc5f5ace dashboard link: https://syzkaller.appspot.com/bug?extid=61958888b1c60361a791 compiler: gcc (GCC) 9.0.0 20181231 (experimental) syz repro: https://syzkaller.appspot.com/x/repro.syz?x=168e6272100000 The bug was bisected to: commit cbe7fba8edfc8cb8e621599e376f8ac5c224fa72 Author: Amir Goldstein <amir73il@xxxxxxxxx> Date: Fri Nov 15 11:33:03 2019 +0000 ovl: make sure that real fid is 32bit aligned in memory bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=11f95922100000 final crash: https://syzkaller.appspot.com/x/report.txt?x=13f95922100000 console output: https://syzkaller.appspot.com/x/log.txt?x=15f95922100000 IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+61958888b1c60361a791@xxxxxxxxxxxxxxxxxxxxxxxxx Fixes: cbe7fba8edfc ("ovl: make sure that real fid is 32bit aligned in memory") ================================================================== BUG: KASAN: slab-out-of-bounds in ovl_check_fb_len+0x171/0x1a0 fs/overlayfs/namei.c:89 Read of size 1 at addr ffff88809727834d by task syz-executor.4/8488 CPU: 0 PID: 8488 Comm: syz-executor.4 Not tainted 5.7.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x188/0x20d lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xd3/0x413 mm/kasan/report.c:382 __kasan_report.cold+0x20/0x38 mm/kasan/report.c:511 kasan_report+0x33/0x50 mm/kasan/common.c:625 ovl_check_fb_len+0x171/0x1a0 fs/overlayfs/namei.c:89 ovl_check_fh_len fs/overlayfs/overlayfs.h:358 [inline] ovl_fh_to_dentry+0x1ab/0x814 fs/overlayfs/export.c:812 exportfs_decode_fh+0x11f/0x717 fs/exportfs/expfs.c:434 --- This bug 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 bug report. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. For information about bisection process see: https://goo.gl/tpsmEJ#bisection syzbot can test patches for this bug, for details see: https://goo.gl/tpsmEJ#testing-patches
