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| author | Luiz Augusto von Dentz <luiz.von.dentz@intel.com> | 2024-10-22 12:31:08 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-11-01 01:56:05 +0100 |
| commit | 9ddda5d967e84796e7df1b54a55f36b4b9f21079 (patch) | |
| tree | 16e0b984b649c5f43bdbb81a7540dfd3e1262438 /net | |
| parent | 5f063bbf1ee6b01611c016b54e050a41506eb794 (diff) | |
| download | linux-9ddda5d967e84796e7df1b54a55f36b4b9f21079.tar.gz linux-9ddda5d967e84796e7df1b54a55f36b4b9f21079.tar.bz2 linux-9ddda5d967e84796e7df1b54a55f36b4b9f21079.zip | |
Bluetooth: SCO: Fix UAF on sco_sock_timeout
[ Upstream commit 1bf4470a3939c678fb822073e9ea77a0560bc6bb ]
conn->sk maybe have been unlinked/freed while waiting for sco_conn_lock
so this checks if the conn->sk is still valid by checking if it part of
sco_sk_list.
Reported-by: syzbot+4c0d0c4cde787116d465@syzkaller.appspotmail.com
Tested-by: syzbot+4c0d0c4cde787116d465@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=4c0d0c4cde787116d465
Fixes: ba316be1b6a0 ("Bluetooth: schedule SCO timeouts with delayed_work")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/bluetooth/af_bluetooth.c | 22 | ||||
| -rw-r--r-- | net/bluetooth/sco.c | 18 |
2 files changed, 34 insertions, 6 deletions
diff --git a/net/bluetooth/af_bluetooth.c b/net/bluetooth/af_bluetooth.c index 0c70172555b4..4c3bd0516038 100644 --- a/net/bluetooth/af_bluetooth.c +++ b/net/bluetooth/af_bluetooth.c @@ -177,6 +177,28 @@ void bt_sock_unlink(struct bt_sock_list *l, struct sock *sk) } EXPORT_SYMBOL(bt_sock_unlink); +bool bt_sock_linked(struct bt_sock_list *l, struct sock *s) +{ + struct sock *sk; + + if (!l || !s) + return false; + + read_lock(&l->lock); + + sk_for_each(sk, &l->head) { + if (s == sk) { + read_unlock(&l->lock); + return true; + } + } + + read_unlock(&l->lock); + + return false; +} +EXPORT_SYMBOL(bt_sock_linked); + void bt_accept_enqueue(struct sock *parent, struct sock *sk, bool bh) { BT_DBG("parent %p, sk %p", parent, sk); diff --git a/net/bluetooth/sco.c b/net/bluetooth/sco.c index 92ea01f9def3..ad5afde17213 100644 --- a/net/bluetooth/sco.c +++ b/net/bluetooth/sco.c @@ -77,6 +77,16 @@ struct sco_pinfo { #define SCO_CONN_TIMEOUT (HZ * 40) #define SCO_DISCONN_TIMEOUT (HZ * 2) +static struct sock *sco_sock_hold(struct sco_conn *conn) +{ + if (!conn || !bt_sock_linked(&sco_sk_list, conn->sk)) + return NULL; + + sock_hold(conn->sk); + + return conn->sk; +} + static void sco_sock_timeout(struct work_struct *work) { struct sco_conn *conn = container_of(work, struct sco_conn, @@ -88,9 +98,7 @@ static void sco_sock_timeout(struct work_struct *work) sco_conn_unlock(conn); return; } - sk = conn->sk; - if (sk) - sock_hold(sk); + sk = sco_sock_hold(conn); sco_conn_unlock(conn); if (!sk) @@ -195,9 +203,7 @@ static void sco_conn_del(struct hci_conn *hcon, int err) /* Kill socket */ sco_conn_lock(conn); - sk = conn->sk; - if (sk) - sock_hold(sk); + sk = sco_sock_hold(conn); sco_conn_unlock(conn); if (sk) { |