[syzbot] UBSAN: shift-out-of-bounds in diNewExt

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    4fe89d07dcc2 Linux 6.0
git tree:       upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=172dd9e0880000
kernel config:  https://syzkaller.appspot.com/x/.config?x=48b99eaecc2b324f
dashboard link: https://syzkaller.appspot.com/bug?extid=e7c25a1325c6112704be
compiler:       Debian clang version 13.0.1-++20220126092033+75e33f71c2da-1~exp1~20220126212112.63, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=128aee24880000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=15e61f70880000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/ce1d9b74a5e0/disk-4fe89d07.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/06e7c02fa7ba/vmlinux-4fe89d07.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+e7c25a1325c6112704be@xxxxxxxxxxxxxxxxxxxxxxxxx

loop0: detected capacity change from 0 to 32768
================================================================================
UBSAN: shift-out-of-bounds in fs/jfs/jfs_imap.c:2177:9
shift exponent 3328 is too large for 64-bit type '__u64' (aka 'unsigned long long')
CPU: 0 PID: 3614 Comm: syz-executor410 Not tainted 6.0.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1b1/0x28e lib/dump_stack.c:106
 ubsan_epilogue lib/ubsan.c:151 [inline]
 __ubsan_handle_shift_out_of_bounds+0x33d/0x3b0 lib/ubsan.c:322
 diNewExt+0x3788/0x3e00 fs/jfs/jfs_imap.c:2177
 diAllocExt fs/jfs/jfs_imap.c:1945 [inline]
 diAllocAG+0xc6a/0x1f80 fs/jfs/jfs_imap.c:1662
 diAlloc+0x3dd/0x1700 fs/jfs/jfs_imap.c:1583
 ialloc+0x8c/0xa80 fs/jfs/jfs_inode.c:56
 jfs_mkdir+0x141/0xb00 fs/jfs/namei.c:225
 vfs_mkdir+0x3b3/0x590 fs/namei.c:4013
 do_mkdirat+0x279/0x550 fs/namei.c:4038
 __do_sys_mkdirat fs/namei.c:4053 [inline]
 __se_sys_mkdirat fs/namei.c:4051 [inline]
 __x64_sys_mkdirat+0x85/0x90 fs/namei.c:4051
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f6d98413009
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff6e1be1f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f6d98413009
RDX: 0000000000000000 RSI: 0000000020000540 RDI: 0000000000000003
RBP: 00007f6d983d27d0 R08: 0000000000000000 R09: 00007f6d983d27d0
R10: 000000000000002e R11: 0000000000000246 R12: 00000000f8008000
R13: 0000000000000000 R14: 00080000000000f8 R15: 0000000000000000
 </TASK>
================================================================================


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