Re: [syzbot] [kernel?] KASAN: slab-out-of-bounds Read in __futex_pivot_hash

[syzbot <syzbot+0a5079ee014f4b907817@syzkaller.appspotmail.com>]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
INFO: trying to register non-static key in futex_hash_prctl

INFO: trying to register non-static key.
The code is fine but needs lockdep annotation, or maybe
you didn't initialize this object before use?
turning off the locking correctness validator.
CPU: 3 UID: 0 PID: 6500 Comm: syz.0.16 Not tainted 6.15.0-syzkaller-gcd2e103d57e5-dirty #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 assign_lock_key kernel/locking/lockdep.c:987 [inline]
 register_lock_class+0x4a3/0x4c0 kernel/locking/lockdep.c:1302
 __lock_acquire+0xa6/0x1c90 kernel/locking/lockdep.c:5115
 lock_acquire kernel/locking/lockdep.c:5871 [inline]
 lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5828
 __mutex_lock_common kernel/locking/mutex.c:602 [inline]
 __mutex_lock+0x199/0xb90 kernel/locking/mutex.c:747
 futex_hash_prctl+0x2fc/0x770 kernel/futex/core.c:1758
 __do_sys_prctl+0x171f/0x24c0 kernel/sys.c:2825
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f516c98e969
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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f516d8a5038 EFLAGS: 00000246 ORIG_RAX: 000000000000009d
RAX: ffffffffffffffda RBX: 00007f516cbb5fa0 RCX: 00007f516c98e969
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 000000000000004e
RBP: 00007f516ca10ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007f516cbb5fa0 R15: 00007ffc88069c38
 </TASK>


Tested on:

commit:         cd2e103d Merge tag 'hardening-v6.16-rc1-fix1-take2' of..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=104b700c580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=4df26174733e11f3
dashboard link: https://syzkaller.appspot.com/bug?extid=0a5079ee014f4b907817
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=1574b970580000