Re: [syzbot] UBSAN: shift-out-of-bounds in dbAllocCtl

[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit:    aaa11ce2ffc8 Add linux-next specific files for 20220923
git tree:       linux-next
console+strace: https://syzkaller.appspot.com/x/log.txt?x=120fd4cc880000
kernel config:  https://syzkaller.appspot.com/x/.config?x=186d1ff305f10294
dashboard link: https://syzkaller.appspot.com/bug?extid=f0e5eba3996857670c88
compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=140d5a0a880000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=12a2f712880000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/95c7bf83c07e/disk-aaa11ce2.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/b161cd56a7a3/vmlinux-aaa11ce2.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+f0e5eba3996857670c88@xxxxxxxxxxxxxxxxxxxxxxxxx

loop0: detected capacity change from 0 to 32768
================================================================================
UBSAN: shift-out-of-bounds in fs/jfs/jfs_dmap.c:1785:12
shift exponent 1635280253 is too large for 64-bit type 'long long int'
CPU: 0 PID: 3609 Comm: syz-executor492 Not tainted 6.0.0-rc6-next-20220923-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+0xcd/0x134 lib/dump_stack.c:106
 ubsan_epilogue+0xb/0x50 lib/ubsan.c:151
 __ubsan_handle_shift_out_of_bounds.cold+0xb1/0x187 lib/ubsan.c:322
 dbAllocCtl.cold+0x75/0x7a fs/jfs/jfs_dmap.c:1785
 dbAllocAG+0x8da/0xd20 fs/jfs/jfs_dmap.c:1334
 dbAlloc+0x40d/0xa70 fs/jfs/jfs_dmap.c:858
 diNewIAG fs/jfs/jfs_imap.c:2500 [inline]
 diAllocExt fs/jfs/jfs_imap.c:1898 [inline]
 diAllocAG+0xb93/0x2200 fs/jfs/jfs_imap.c:1662
 diAlloc+0x82d/0x1730 fs/jfs/jfs_imap.c:1583
 ialloc+0x89/0xaa0 fs/jfs/jfs_inode.c:56
 jfs_mkdir+0x1f0/0xab0 fs/jfs/namei.c:225
 vfs_mkdir+0x489/0x740 fs/namei.c:4013
 do_mkdirat+0x28c/0x310 fs/namei.c:4038
 __do_sys_mkdirat fs/namei.c:4053 [inline]
 __se_sys_mkdirat fs/namei.c:4051 [inline]
 __x64_sys_mkdirat+0x115/0x170 fs/namei.c:4051
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f732d8ecdd9
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:00007fff2953b988 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f732d8ecdd9
RDX: 0000000000000000 RSI: 0000000020000540 RDI: 0000000000000003
RBP: 00007f732d8ac5a0 R08: 0000000000000000 R09: 00007f732d8ac5a0
R10: 000055555602c2c0 R11: 0000000000000246 R12: 0000000200000004
R13: 0000000000000000 R14: 00080000000000f4 R15: 0000000000000000
 </TASK>
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