[PATCH 4.14 27/37] Bluetooth: Fix bt_skb_sendmmsg not allocating partial chunks

Greg Kroah-Hartman
2022-07-27T16:27:40Z

From: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

commit 29fb608396d6a62c1b85acc421ad7a4399085b9f upstream.

Since bt_skb_sendmmsg can be used with the likes of SOCK_STREAM it
shall return the partial chunks it could allocate instead of freeing
everything as otherwise it can cause problems like bellow.

Fixes: 81be03e026dc ("Bluetooth: RFCOMM: Replace use of memcpy_from_msg with bt_skb_sendmmsg")
Reported-by: Paul Menzel <pmenzel@molgen.mpg.de>
Link: https://lore.kernel.org/r/d7206e12-1b99-c3be-84f4-df22af427ef5@molgen.mpg.de
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=215594
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Tested-by: Paul Menzel <pmenzel@molgen.mpg.de> (Nokia N9 (MeeGo/Harmattan)
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Cc: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
include/net/bluetooth/bluetooth.h | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

--- a/include/net/bluetooth/bluetooth.h
+++ b/include/net/bluetooth/bluetooth.h
@@ -420,8 +420,7 @@ static inline struct sk_buff *bt_skb_sen

tmp = bt_skb_sendmsg(sk, msg, len, mtu, headroom, tailroom);
if (IS_ERR(tmp)) {
- kfree_skb(skb);
- return tmp;
+ return skb;
}

len -= tmp->len;