Bluetooth: L2CAP: use proto_lock for l2cap_data to fix l2cap_disconn_ind

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hci_conn::l2cap_data is accessed without locks in l2cap_disconn_ind via
hci_conn_timeout (disc_work) -> hci_proto_disconn_ind ->
l2cap_disconn_ind.  This is UAF if the l2cap_conn is deleted
concurrently.

disc_work is disabled sync in hci_conn_del(), so we cannot take
hci_dev_lock in disc_work.

Fix by using proto_lock to guard l2cap_data, in addition to hdev->lock
which is held in other access paths.

Fixes: ab4eedb790 ("Bluetooth: L2CAP: Fix corrupted list in hci_chan_del")
Reported-by: syzbot+9c40ad7c6ed7165e46e8@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=9c40ad7c6ed7165e46e8
Signed-off-by: Pauli Virtanen <pav@iki.fi>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

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Pauli Virtanen 2026-08-01 21:37:23 +03:00 • committed by Luiz Augusto von Dentz

parent 502adc06ba

commit 2b66c83ff1

1 changed files with 17 additions and 6 deletions

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net/bluetooth/l2cap_core.c

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