binder: fix use-after-free in binderfs_evict_inode()

Running 'stress-ng --binderfs 16 --timeout 300' under KASAN-enabled
kernel, I've noticed the following:

BUG: KASAN: slab-use-after-free in binderfs_evict_inode+0x1de/0x2d0
Write of size 8 at addr ffff88807379bc08 by task stress-ng-binde/1699

CPU: 0 UID: 0 PID: 1699 Comm: stress-ng-binde Not tainted 6.14.0-rc7-g586de92313fc-dirty #13
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-3.fc41 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x1c2/0x2a0
? __pfx_dump_stack_lvl+0x10/0x10
? __pfx__printk+0x10/0x10
? __pfx_lock_release+0x10/0x10
? __virt_addr_valid+0x18c/0x540
? __virt_addr_valid+0x469/0x540
print_report+0x155/0x840
? __virt_addr_valid+0x18c/0x540
? __virt_addr_valid+0x469/0x540
? __phys_addr+0xba/0x170
? binderfs_evict_inode+0x1de/0x2d0
kasan_report+0x147/0x180
? binderfs_evict_inode+0x1de/0x2d0
binderfs_evict_inode+0x1de/0x2d0
? __pfx_binderfs_evict_inode+0x10/0x10
evict+0x524/0x9f0
? __pfx_lock_release+0x10/0x10
? __pfx_evict+0x10/0x10
? do_raw_spin_unlock+0x4d/0x210
? _raw_spin_unlock+0x28/0x50
? iput+0x697/0x9b0
__dentry_kill+0x209/0x660
? shrink_kill+0x8d/0x2c0
shrink_kill+0xa9/0x2c0
shrink_dentry_list+0x2e0/0x5e0
shrink_dcache_parent+0xa2/0x2c0
? __pfx_shrink_dcache_parent+0x10/0x10
? __pfx_lock_release+0x10/0x10
? __pfx_do_raw_spin_lock+0x10/0x10
do_one_tree+0x23/0xe0
shrink_dcache_for_umount+0xa0/0x170
generic_shutdown_super+0x67/0x390
kill_litter_super+0x76/0xb0
binderfs_kill_super+0x44/0x90
deactivate_locked_super+0xb9/0x130
cleanup_mnt+0x422/0x4c0
? lockdep_hardirqs_on+0x9d/0x150
task_work_run+0x1d2/0x260
? __pfx_task_work_run+0x10/0x10
resume_user_mode_work+0x52/0x60
syscall_exit_to_user_mode+0x9a/0x120
do_syscall_64+0x103/0x210
? asm_sysvec_apic_timer_interrupt+0x1a/0x20
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0xcac57b
Code: c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 f3 0f 1e fa 31 f6 e9 05 00 00 00 0f 1f 44 00 00 f3 0f 1e fa b8
RSP: 002b:00007ffecf4226a8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007ffecf422720 RCX: 0000000000cac57b
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007ffecf422850
RBP: 00007ffecf422850 R08: 0000000028d06ab1 R09: 7fffffffffffffff
R10: 3fffffffffffffff R11: 0000000000000246 R12: 00007ffecf422718
R13: 00007ffecf422710 R14: 00007f478f87b658 R15: 00007ffecf422830
</TASK>

Allocated by task 1705:
kasan_save_track+0x3e/0x80
__kasan_kmalloc+0x8f/0xa0
__kmalloc_cache_noprof+0x213/0x3e0
binderfs_binder_device_create+0x183/0xa80
binder_ctl_ioctl+0x138/0x190
__x64_sys_ioctl+0x120/0x1b0
do_syscall_64+0xf6/0x210
entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 1705:
kasan_save_track+0x3e/0x80
kasan_save_free_info+0x46/0x50
__kasan_slab_free+0x62/0x70
kfree+0x194/0x440
evict+0x524/0x9f0
do_unlinkat+0x390/0x5b0
__x64_sys_unlink+0x47/0x50
do_syscall_64+0xf6/0x210
entry_SYSCALL_64_after_hwframe+0x77/0x7f

This 'stress-ng' workload causes the concurrent deletions from
'binder_devices' and so requires full-featured synchronization
to prevent list corruption.

I've found this issue independently but pretty sure that syzbot did
the same, so Reported-by: and Closes: should be applicable here as well.

Cc: stable@vger.kernel.org
Reported-by: syzbot+353d7b75658a95aa955a@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=353d7b75658a95aa955a
Fixes: e77aff5528a18 ("binderfs: fix use-after-free in binder_devices")
Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru>
Acked-by: Carlos Llamas <cmllamas@google.com>
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20250517170957.1317876-1-cmllamas@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>