Subject: [syzbot] KMSAN: uninit-value in hci_conn_complete_evt

From: syzbot <[email-masked]>
Date: Sun, 28 Nov 2021 01:22:17 -0800

Hello,

syzbot found the following issue on:

HEAD commit:    a535b0caaa2f Revert "DO-NOT-SUBMIT: kmsan: suppress a repo..
git tree:       https://github.com/google/kmsan.git master
console output: https://syzkaller.appspot.com/x/log.txt?x=10becf06b00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=2d142cdf4204061
dashboard link: https://syzkaller.appspot.com/bug?extid=dcb7d98a388eafb85ecb
compiler:       clang version 14.0.0 ([email-masked]:llvm/llvm-project.git 0996585c8e3b3d409494eb5f1cad714b9e1f7fb5), GNU ld (GNU Binutils for Debian) 2.35.2

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

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: [email-masked]

=====================================================
BUG: KMSAN: uninit-value in hci_conn_complete_evt+0x8e7/0x1de0 net/bluetooth/hci_event.c:2668
 hci_conn_complete_evt+0x8e7/0x1de0 net/bluetooth/hci_event.c:2668
 hci_event_packet+0x1670/0x22e0 net/bluetooth/hci_event.c:6311
 hci_rx_work+0x6ae/0xd10 net/bluetooth/hci_core.c:5136
 process_one_work+0xdc7/0x1760 kernel/workqueue.c:2297
 worker_thread+0x1101/0x22b0 kernel/workqueue.c:2444
 kthread+0x66b/0x780 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30

Uninit was created at:
 slab_post_alloc_hook mm/slab.h:524 [inline]
 slab_alloc_node mm/slub.c:3227 [inline]
 __kmalloc_node_track_caller+0xa3b/0x13c0 mm/slub.c:4962
 kmalloc_reserve net/core/skbuff.c:356 [inline]
 __alloc_skb+0x4db/0xe40 net/core/skbuff.c:427
 alloc_skb include/linux/skbuff.h:1116 [inline]
 bt_skb_alloc include/net/bluetooth/bluetooth.h:389 [inline]
 bcsp_recv+0x1550/0x2120 drivers/bluetooth/hci_bcsp.c:673
 hci_uart_tty_receive+0x345/0x7a0 drivers/bluetooth/hci_ldisc.c:613
 tty_ldisc_receive_buf+0x32a/0x390 drivers/tty/tty_buffer.c:475
 tty_port_default_receive_buf+0x14b/0x1e0 drivers/tty/tty_port.c:39
 receive_buf drivers/tty/tty_buffer.c:491 [inline]
 flush_to_ldisc+0x3b5/0x940 drivers/tty/tty_buffer.c:543
 process_one_work+0xdc7/0x1760 kernel/workqueue.c:2297
 worker_thread+0x1101/0x22b0 kernel/workqueue.c:2444
 kthread+0x66b/0x780 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30
=====================================================

---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at [email-masked].

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.