[v5.15] KASAN: use-after-free Read in __lock_sock (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 0c935c049b5c Linux 5.15.179
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=157edb4c580000
kernel config: https://syzkaller.appspot.com/x/.config?x=98c228fbc016eb3a
dashboard link: https://syzkaller.appspot.com/bug?extid=7c75c478e22471f63ba2
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: arm64

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/d5477072f336/disk-0c935c04.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/77d15907ffb3/vmlinux-0c935c04.xz
kernel image: https://storage.googleapis.com/syzbot-assets/efe5d79cb16a/Image-0c935c04.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+7c75c4...@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: use-after-free in __lock_acquire+0x114/0x7638 kernel/locking/lockdep.c:4882
Read of size 8 at addr ffff0000c22480a0 by task kworker/u5:1/4025

CPU: 1 PID: 4025 Comm: kworker/u5:1 Not tainted 5.15.179-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Workqueue: hci2 hci_rx_work
Call trace:
dump_backtrace+0x0/0x530 arch/arm64/kernel/stacktrace.c:152
show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:216
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x108/0x170 lib/dump_stack.c:106
print_address_description+0x7c/0x3f0 mm/kasan/report.c:248
__kasan_report mm/kasan/report.c:434 [inline]
kasan_report+0x174/0x1e4 mm/kasan/report.c:451
__asan_report_load8_noabort+0x44/0x50 mm/kasan/report_generic.c:309
__lock_acquire+0x114/0x7638 kernel/locking/lockdep.c:4882
lock_acquire+0x240/0x77c kernel/locking/lockdep.c:5623
__raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
_raw_spin_lock_bh+0x124/0x1c4 kernel/locking/spinlock.c:178
spin_lock_bh include/linux/spinlock.h:368 [inline]
__lock_sock+0x170/0x2d4 net/core/sock.c:2704
lock_sock_nested+0x138/0x1ec net/core/sock.c:3258
lock_sock include/net/sock.h:1684 [inline]
l2cap_sock_recv_cb+0x5c/0x1c0 net/bluetooth/l2cap_sock.c:1499
l2cap_conless_channel net/bluetooth/l2cap_core.c:7765 [inline]
l2cap_recv_frame+0xeb4/0x6c28 net/bluetooth/l2cap_core.c:7819
l2cap_recv_acldata+0x4f4/0x163c net/bluetooth/l2cap_core.c:8531
hci_acldata_packet net/bluetooth/hci_core.c:4973 [inline]
hci_rx_work+0x3a8/0x830 net/bluetooth/hci_core.c:5165
process_one_work+0x790/0x11b8 kernel/workqueue.c:2310
worker_thread+0x910/0x1034 kernel/workqueue.c:2457
kthread+0x37c/0x45c kernel/kthread.c:334
ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870

Allocated by task 6292:
kasan_save_stack mm/kasan/common.c:38 [inline]
kasan_set_track mm/kasan/common.c:46 [inline]
set_alloc_info mm/kasan/common.c:434 [inline]
____kasan_kmalloc+0xbc/0xfc mm/kasan/common.c:513
__kasan_kmalloc+0x10/0x1c mm/kasan/common.c:522
kasan_kmalloc include/linux/kasan.h:264 [inline]
__kmalloc+0x29c/0x4c8 mm/slub.c:4407
kmalloc include/linux/slab.h:596 [inline]
sk_prot_alloc+0xc4/0x1f0 net/core/sock.c:1866
sk_alloc+0x40/0x3dc net/core/sock.c:1919
l2cap_sock_alloc net/bluetooth/l2cap_sock.c:1861 [inline]
l2cap_sock_create+0x140/0x368 net/bluetooth/l2cap_sock.c:1909
bt_sock_create+0x14c/0x248 net/bluetooth/af_bluetooth.c:130
__sock_create+0x43c/0x8a0 net/socket.c:1486
sock_create net/socket.c:1542 [inline]
__sys_socket+0x168/0x310 net/socket.c:1584
__do_sys_socket net/socket.c:1593 [inline]
__se_sys_socket net/socket.c:1591 [inline]
__arm64_sys_socket+0x7c/0x94 net/socket.c:1591
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608
el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626
el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584

Freed by task 6292:
kasan_save_stack mm/kasan/common.c:38 [inline]
kasan_set_track+0x4c/0x84 mm/kasan/common.c:46
kasan_set_free_info+0x28/0x4c mm/kasan/generic.c:360
____kasan_slab_free+0x118/0x164 mm/kasan/common.c:366
__kasan_slab_free+0x18/0x28 mm/kasan/common.c:374
kasan_slab_free include/linux/kasan.h:230 [inline]
slab_free_hook mm/slub.c:1705 [inline]
slab_free_freelist_hook+0x128/0x1ec mm/slub.c:1731
slab_free mm/slub.c:3499 [inline]
kfree+0x178/0x410 mm/slub.c:4559
sk_prot_free net/core/sock.c:1902 [inline]
__sk_destruct+0x41c/0x604 net/core/sock.c:1988
sk_destruct net/core/sock.c:2003 [inline]
__sk_free+0x388/0x4f4 net/core/sock.c:2014
sk_free+0x68/0xdc net/core/sock.c:2025
sock_put include/net/sock.h:1929 [inline]
l2cap_sock_kill+0x114/0x228 net/bluetooth/l2cap_sock.c:1258
l2cap_sock_release+0x138/0x1b4 net/bluetooth/l2cap_sock.c:1429
__sock_release net/socket.c:649 [inline]
sock_close+0xb8/0x1fc net/socket.c:1336
__fput+0x1c4/0x800 fs/file_table.c:311
____fput+0x20/0x30 fs/file_table.c:339
task_work_run+0x130/0x1e4 kernel/task_work.c:188
get_signal+0x1450/0x1550 kernel/signal.c:2672
do_signal arch/arm64/kernel/signal.c:890 [inline]
do_notify_resume+0x3d0/0x32b8 arch/arm64/kernel/signal.c:943
prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:133 [inline]
exit_to_user_mode arch/arm64/kernel/entry-common.c:138 [inline]
el0_svc+0xfc/0x1f0 arch/arm64/kernel/entry-common.c:609
el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626
el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584

The buggy address belongs to the object at ffff0000c2248000
which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 160 bytes inside of
2048-byte region [ffff0000c2248000, ffff0000c2248800)
The buggy address belongs to the page:
page:00000000cd5ba82b refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff0000c2249000 pfn:0x102248
head:00000000cd5ba82b order:3 compound_mapcount:0 compound_pincount:0
flags: 0x5ffc00000010200(slab|head|node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc00000010200 fffffc00033f1e08 fffffc00036b1008 ffff0000c0002900
raw: ffff0000c2249000 0000000000080007 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
ffff0000c2247f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff0000c2248000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff0000c2248080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff0000c2248100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff0000c2248180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.