[syzbot] UBSAN: array-index-out-of-bounds in dbNextAG

[syzbot] UBSAN: array-index-out-of-bounds in dbNextAG

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    105a36f3694e Merge tag 'kbuild-fixes-v6.0-3' of git://git...
git tree:       upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=105311df080000
kernel config:  https://syzkaller.appspot.com/x/.config?x=c221af36f6d1d811
dashboard link: https://syzkaller.appspot.com/bug?extid=38e876a8aa44b7115c76
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=100105c4880000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=17a5fcdf080000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/858ea4fd6806/disk-105a36f3.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/76c66678f029/vmlinux-105a36f3.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+38e876a8aa44b7115c76@syzkaller.appspotmail.com

loop0: detected capacity change from 0 to 264192
================================================================================
UBSAN: array-index-out-of-bounds in fs/jfs/jfs_dmap.c:617:20
index 1128417612 is out of range for type 'atomic_t [128]'
CPU: 0 PID: 3606 Comm: syz-executor376 Not tainted 6.0.0-rc6-syzkaller-00321-g105a36f3694e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022
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_out_of_bounds+0xdb/0x130 lib/ubsan.c:283
 dbNextAG+0x602/0x630 fs/jfs/jfs_dmap.c:617
 diAlloc+0x17a/0x1700 fs/jfs/jfs_imap.c:1342
 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_mkdir fs/namei.c:4058 [inline]
 __se_sys_mkdir fs/namei.c:4056 [inline]
 __x64_sys_mkdir+0x6a/0x80 fs/namei.c:4056
 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: 0033:0x7fca2c28c2c7
Code: ff ff ff ff c3 66 0f 1f 44 00 00 48 c7 c0 c0 ff ff ff 64 c7 00 16 00 00 00 b8 ff ff ff ff c3 0f 1f 40 00 b8 53 00 00 00 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:00007fff8fb1d868 EFLAGS: 00000246 ORIG_RAX: 0000000000000053
RAX: ffffffffffffffda RBX: 00007fff8fb1d910 RCX: 00007fca2c28c2c7
RDX: 0000000000000000 RSI: 00000000000001ff RDI: 00000000200001c0
RBP: 00000000ffffffff R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00000000ffffffff R14: 00000000200001c0 R15: 0000000000000000
 </TASK>
================================================================================


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