Hello, syzbot found the following issue on: HEAD commit: 15ac8fdb Add linux-next specific files for 20201207 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=1125c923500000 kernel config: https://syzkaller.appspot.com/x/.config?x=3696b8138207d24d dashboard link: https://syzkaller.appspot.com/bug?extid=345b75652b1d24227443 compiler: gcc (GCC) 10.1.0-syz 20200507 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=151bf86b500000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=139212cb500000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+345b75652b1d24227443@xxxxxxxxxxxxxxxxxxxxxxxxx loop0: detected capacity change from 4 to 0 ================================================================================ UBSAN: shift-out-of-bounds in fs/ext4/super.c:4190:25 shift exponent 589825 is too large for 32-bit type 'int' CPU: 1 PID: 8498 Comm: syz-executor023 Not tainted 5.10.0-rc6-next-20201207-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x107/0x163 lib/dump_stack.c:120 ubsan_epilogue+0xb/0x5a lib/ubsan.c:148 __ubsan_handle_shift_out_of_bounds.cold+0xb1/0x181 lib/ubsan.c:395 ext4_fill_super.cold+0x154/0x3ce fs/ext4/super.c:4190 mount_bdev+0x34d/0x410 fs/super.c:1366 legacy_get_tree+0x105/0x220 fs/fs_context.c:592 vfs_get_tree+0x89/0x2f0 fs/super.c:1496 do_new_mount fs/namespace.c:2896 [inline] path_mount+0x12ae/0x1e70 fs/namespace.c:3227 do_mount fs/namespace.c:3240 [inline] __do_sys_mount fs/namespace.c:3448 [inline] __se_sys_mount fs/namespace.c:3425 [inline] __x64_sys_mount+0x27f/0x300 fs/namespace.c:3425 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x446d6a Code: b8 08 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 fd ad fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 da ad fb ff c3 66 0f 1f 84 00 00 00 00 00 RSP: 002b:00007ffc2d215018 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007ffc2d215070 RCX: 0000000000446d6a RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007ffc2d215030 RBP: 00007ffc2d215030 R08: 00007ffc2d215070 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000001 R13: 0000000000000004 R14: 0000000000000003 R15: 0000000000000003 ================================================================================ --- 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. syzbot can test patches for this issue, for details see: https://goo.gl/tpsmEJ#testing-patches
