[Android 6.1] UBSAN: shift-out-of-bounds in ext4_check_opt_consistency

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 5e6db7045704 ANDROID: oplus add symbols to symbol list
git tree: android14-6.1
console output: https://syzkaller.appspot.com/x/log.txt?x=10719efc580000
kernel config: https://syzkaller.appspot.com/x/.config?x=5bf7cc5fd4a155df
dashboard link: https://syzkaller.appspot.com/bug?extid=04b7043650d5edd3069b
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=175e1fda580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1679cf92580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/b9c98e8c23f9/disk-5e6db704.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/3ded6740135d/vmlinux-5e6db704.xz
kernel image: https://storage.googleapis.com/syzbot-assets/117ac2d547f7/bzImage-5e6db704.xz
mounted in repro #1: https://storage.googleapis.com/syzbot-assets/0246a3aef465/mount_0.gz
fsck result: failed (log: https://syzkaller.appspot.com/x/fsck.log?x=1279cf92580000)
mounted in repro #2: https://storage.googleapis.com/syzbot-assets/813620ab3e2e/mount_5.gz
fsck result: failed (log: https://syzkaller.appspot.com/x/fsck.log?x=111d3f84580000)

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+04b704...@syzkaller.appspotmail.com

EXT4-fs error (device loop2): ext4_free_branches:1030: inode #11: comm syz.2.17: invalid indirect mapped block 1811939328 (level 0)
EXT4-fs (loop2): Remounting filesystem read-only
EXT4-fs error (device loop2): ext4_free_branches:1030: inode #11: comm syz.2.17: invalid indirect mapped block 2185560079 (level 1)
EXT4-fs (loop2): Remounting filesystem read-only
EXT4-fs (loop2): 1 truncate cleaned up
EXT4-fs (loop2): mounted filesystem without journal. Quota mode: none.
EXT4-fs: Ignoring removed mblk_io_submit option
================================================================================
UBSAN: shift-out-of-bounds in fs/ext4/super.c:2704:15
shift exponent 808464432 is too large for 32-bit type 'int'
CPU: 1 PID: 375 Comm: syz.2.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
<TASK>
__dump_stack+0x21/0x24 lib/dump_stack.c:88
dump_stack_lvl+0xee/0x150 lib/dump_stack.c:106
dump_stack+0x15/0x24 lib/dump_stack.c:113
ubsan_epilogue+0xe/0x40 lib/ubsan.c:151
__ubsan_handle_shift_out_of_bounds+0x37c/0x400 lib/ubsan.c:321
ext4_check_opt_consistency+0x138d/0x1720 fs/ext4/super.c:2704
ext4_reconfigure+0xc7/0x2800 fs/ext4/super.c:6649
reconfigure_super+0x228/0x890 fs/super.c:979
do_remount fs/namespace.c:2741 [inline]
path_mount+0xdea/0x1010 fs/namespace.c:3400
do_mount fs/namespace.c:3421 [inline]
__do_sys_mount fs/namespace.c:3629 [inline]
__se_sys_mount+0x318/0x380 fs/namespace.c:3606
__x64_sys_mount+0xbf/0xd0 fs/namespace.c:3606
x64_sys_call+0x65d/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:166
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f6575990eea
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe22127d88 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ffe22127e10 RCX: 00007f6575990eea
RDX: 0000200000000180 RSI: 0000200000000000 RDI: 0000000000000000
RBP: 0000200000000180 R08: 00007ffe22127e10 R09: 0000000001b7a434
R10: 0000000001b7a434 R11: 0000000000000246 R12: 0000200000000000
R13: 00007ffe22127dd0 R14: 0000000000000000 R15: 00002000000003c0
</TASK>
================================================================================


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