Re: [syzbot] [bluetooth?] [usb?] memory leak in __hci_cmd_sync_sk

syzbot
2025-11-18T03:24:04Z

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
memory leak in __hci_cmd_sync_sk

BUG: memory leak
unreferenced object 0xffff888109a2de00 (size 240):
comm "kworker/u9:3", pid 6352, jiffies 4294946920
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace (crc ee2326c6):
kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
slab_post_alloc_hook mm/slub.c:4983 [inline]
slab_alloc_node mm/slub.c:5288 [inline]
kmem_cache_alloc_node_noprof+0x36f/0x5e0 mm/slub.c:5340
__alloc_skb+0x203/0x240 net/core/skbuff.c:660
alloc_skb include/linux/skbuff.h:1383 [inline]
bt_skb_alloc include/net/bluetooth/bluetooth.h:510 [inline]
hci_cmd_sync_alloc+0x30/0x140 net/bluetooth/hci_sync.c:58
hci_cmd_sync_add net/bluetooth/hci_sync.c:99 [inline]
__hci_cmd_sync_sk+0x85/0x530 net/bluetooth/hci_sync.c:168
__hci_cmd_sync_ev+0x3e/0x50 net/bluetooth/hci_sync.c:253
send_hci_cmd_sync+0x5e/0xf0 net/bluetooth/mgmt.c:2615
hci_cmd_sync_work+0xd5/0x160 net/bluetooth/hci_sync.c:335
process_one_work+0x26b/0x620 kernel/workqueue.c:3263
process_scheduled_works kernel/workqueue.c:3346 [inline]
worker_thread+0x2c4/0x4f0 kernel/workqueue.c:3427
kthread+0x15b/0x310 kernel/kthread.c:463
ret_from_fork+0x210/0x240 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

connection error: failed to recv *flatrpc.ExecutorMessageRawT: EOF

Tested on:

commit: e7c375b1 Merge tag 'vfs-6.18-rc7.fixes' of gitolite.ke..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1078e212580000
kernel config: https://syzkaller.appspot.com/x/.config?x=f30cc590c4f6da44
dashboard link: https://syzkaller.appspot.com/bug?extid=f098d64cc684b8dbaf65
compiler: gcc (Debian 12.2.0-14+deb12u1) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
patch: https://syzkaller.appspot.com/x/patch.diff?x=1412f212580000