]> git.proxmox.com Git - mirror_ubuntu-kernels.git/commit
Bluetooth: Refcnt drop must be placed last in hci_conn_unlink
authorRuihan Li <lrh2000@pku.edu.cn>
Wed, 3 May 2023 13:39:35 +0000 (21:39 +0800)
committerLuiz Augusto von Dentz <luiz.von.dentz@intel.com>
Fri, 19 May 2023 22:37:45 +0000 (15:37 -0700)
commit2910431ab0e500dfc5df12299bb15eef0f30b43e
tree0e8602d8977512314b7d7780f3d119c1df38675f
parentca1fd42e7dbfcb34890ffbf1f2f4b356776dab6f
Bluetooth: Refcnt drop must be placed last in hci_conn_unlink

If hci_conn_put(conn->parent) reduces conn->parent's reference count to
zero, it can immediately deallocate conn->parent. At the same time,
conn->link->list has its head in conn->parent, causing use-after-free
problems in the latter list_del_rcu(&conn->link->list).

This problem can be easily solved by reordering the two operations,
i.e., first performing the list removal with list_del_rcu and then
decreasing the refcnt with hci_conn_put.

Reported-by: Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Closes: https://lore.kernel.org/linux-bluetooth/CABBYNZ+1kce8_RJrLNOXd_8=Mdpb=2bx4Nto-hFORk=qiOkoCg@mail.gmail.com/
Fixes: 06149746e720 ("Bluetooth: hci_conn: Add support for linking multiple hcon")
Signed-off-by: Ruihan Li <lrh2000@pku.edu.cn>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
net/bluetooth/hci_conn.c