[syzbot] [jfs?] UBSAN: shift-out-of-bounds in dbSplit (2)

[syzbot <syzbot+b5ca8a249162c4b9a7d0@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    a6bd6c933339 Add linux-next specific files for 20240328
git tree:       linux-next
console+strace: https://syzkaller.appspot.com/x/log.txt?x=179ebb76180000
kernel config:  https://syzkaller.appspot.com/x/.config?x=b0058bda1436e073
dashboard link: https://syzkaller.appspot.com/bug?extid=b5ca8a249162c4b9a7d0
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=13ef71f9180000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=132cf70d180000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/7c1618ff7d25/disk-a6bd6c93.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/875519f620fe/vmlinux-a6bd6c93.xz
kernel image: https://storage.googleapis.com/syzbot-assets/ad92b057fb96/bzImage-a6bd6c93.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/0e8af372eab3/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+b5ca8a249162c4b9a7d0@syzkaller.appspotmail.com

loop0: detected capacity change from 0 to 32768
------------[ cut here ]------------
UBSAN: shift-out-of-bounds in fs/jfs/jfs_dmap.c:2639:11
shift exponent 121 is too large for 32-bit type 'int'
CPU: 0 PID: 5079 Comm: syz-executor118 Not tainted 6.9.0-rc1-next-20240328-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
 ubsan_epilogue lib/ubsan.c:217 [inline]
 __ubsan_handle_shift_out_of_bounds+0x3c8/0x420 lib/ubsan.c:454
 dbSplit+0x21a/0x220 fs/jfs/jfs_dmap.c:2639
 dbAllocBits+0x4e5/0x9a0 fs/jfs/jfs_dmap.c:2191
 dbAllocDmap fs/jfs/jfs_dmap.c:2032 [inline]
 dbAllocDmapLev+0x250/0x4a0 fs/jfs/jfs_dmap.c:1986
 dbAllocCtl+0x113/0x920 fs/jfs/jfs_dmap.c:1823
 dbAllocAG+0x28f/0x10b0 fs/jfs/jfs_dmap.c:1364
 dbAlloc+0x658/0xca0 fs/jfs/jfs_dmap.c:888
 dtSplitUp fs/jfs/jfs_dtree.c:979 [inline]
 dtInsert+0xda7/0x6b00 fs/jfs/jfs_dtree.c:868
 jfs_create+0x7ba/0xb90 fs/jfs/namei.c:137
 lookup_open fs/namei.c:3497 [inline]
 open_last_lookups fs/namei.c:3566 [inline]
 path_openat+0x1425/0x3240 fs/namei.c:3796
 do_filp_open+0x235/0x490 fs/namei.c:3826
 do_sys_openat2+0x13e/0x1d0 fs/open.c:1406
 do_sys_open fs/open.c:1421 [inline]
 __do_sys_open fs/open.c:1429 [inline]
 __se_sys_open fs/open.c:1425 [inline]
 __x64_sys_open+0x225/0x270 fs/open.c:1425
 do_syscall_64+0xfb/0x240
 entry_SYSCALL_64_after_hwframe+0x6d/0x75
RIP: 0033:0x7faf13ba19b9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 61 17 00 00 90 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff9504bea8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 00007fff9504c088 RCX: 00007faf13ba19b9
RDX: 0000000000000000 RSI: 0000000000000040 RDI: 0000000020000400
RBP: 00007faf13c1a610 R08: 00000000000060cc R09: 0000000000000000
R10: 00007fff9504bd70 R11: 0000000000000246 R12: 0000000000000001
R13: 00007fff9504c078 R14: 0000000000000001 R15: 0000000000000001
 </TASK>
---[ end trace ]---


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