This is a note to let you know that I've just added the patch titled
udp: fix integer overflow while computing available space in sk_rcvbuf
to the 4.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
udp-fix-integer-overflow-while-computing-available-space-in-sk_rcvbuf.patch
and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Thu 02 Jan 2020 11:13:41 AM CET
From: Antonio Messina <amessina@xxxxxxxxxx>
Date: Thu, 19 Dec 2019 15:08:03 +0100
Subject: udp: fix integer overflow while computing available space in sk_rcvbuf
From: Antonio Messina <amessina@xxxxxxxxxx>
[ Upstream commit feed8a4fc9d46c3126fb9fcae0e9248270c6321a ]
When the size of the receive buffer for a socket is close to 2^31 when
computing if we have enough space in the buffer to copy a packet from
the queue to the buffer we might hit an integer overflow.
When an user set net.core.rmem_default to a value close to 2^31 UDP
packets are dropped because of this overflow. This can be visible, for
instance, with failure to resolve hostnames.
This can be fixed by casting sk_rcvbuf (which is an int) to unsigned
int, similarly to how it is done in TCP.
Signed-off-by: Antonio Messina <amessina@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/ipv4/udp.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -1338,7 +1338,7 @@ int __udp_enqueue_schedule_skb(struct so
* queue contains some other skb
*/
rmem = atomic_add_return(size, &sk->sk_rmem_alloc);
- if (rmem > (size + sk->sk_rcvbuf))
+ if (rmem > (size + (unsigned int)sk->sk_rcvbuf))
goto uncharge_drop;
spin_lock(&list->lock);
Patches currently in stable-queue which might be from amessina@xxxxxxxxxx are
queue-4.14/udp-fix-integer-overflow-while-computing-available-space-in-sk_rcvbuf.patch
