Hello, syzbot found the following issue on: HEAD commit: 6642d600 Merge tag '5.11-rc5-smb3' of git://git.samba.org/.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=16f064acd00000 kernel config: https://syzkaller.appspot.com/x/.config?x=9408d1770a50819c dashboard link: https://syzkaller.appspot.com/bug?extid=a8b4b0c60155e87e9484 compiler: clang version 11.0.1 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=127be3d8d00000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1065a9e8d00000 The issue was bisected to: commit cfd73237722135807967f389bcbda558a60a30d6 Author: Alex Zhuravlev <bzzz@xxxxxxxxxxxxx> Date: Tue Apr 21 07:54:07 2020 +0000 ext4: add prefetching for block allocation bitmaps bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=13b5c1d8d00000 final oops: https://syzkaller.appspot.com/x/report.txt?x=1075c1d8d00000 console output: https://syzkaller.appspot.com/x/log.txt?x=17b5c1d8d00000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+a8b4b0c60155e87e9484@xxxxxxxxxxxxxxxxxxxxxxxxx Fixes: cfd732377221 ("ext4: add prefetching for block allocation bitmaps") loop0: detected capacity change from 264192 to 0 ================================================================================ UBSAN: shift-out-of-bounds in fs/ext4/mballoc.c:2713:24 shift exponent 60 is too large for 32-bit type 'int' CPU: 1 PID: 8433 Comm: syz-executor484 Not tainted 5.11.0-rc5-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+0x137/0x1be lib/dump_stack.c:120 ubsan_epilogue lib/ubsan.c:148 [inline] __ubsan_handle_shift_out_of_bounds+0x432/0x4d0 lib/ubsan.c:395 ext4_mb_init_backend fs/ext4/mballoc.c:2713 [inline] ext4_mb_init+0x19bc/0x19f0 fs/ext4/mballoc.c:2898 ext4_fill_super+0xc2ec/0xfbe0 fs/ext4/super.c:4983 mount_bdev+0x26c/0x3a0 fs/super.c:1366 legacy_get_tree+0xea/0x180 fs/fs_context.c:592 vfs_get_tree+0x86/0x270 fs/super.c:1496 do_new_mount fs/namespace.c:2881 [inline] path_mount+0x17ad/0x2a00 fs/namespace.c:3211 do_mount fs/namespace.c:3224 [inline] __do_sys_mount fs/namespace.c:3432 [inline] __se_sys_mount+0x28c/0x320 fs/namespace.c:3409 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x44710a 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:00007ffc5b95ff48 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007ffc5b95ffa0 RCX: 000000000044710a RDX: 0000000020000000 RSI: 0000000020000180 RDI: 00007ffc5b95ff60 RBP: 00007ffc5b95ff60 R08: 00007ffc5b95ffa0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000013 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. For information about bisection process see: https://goo.gl/tpsmEJ#bisection syzbot can test patches for this issue, for details see: https://goo.gl/tpsmEJ#testing-patches
