This is a note to let you know that I've just added the patch titled
net: avoid signed overflows for SO_{SND|RCV}BUFFORCE
to the 4.4-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:
net-avoid-signed-overflows-for-so_-snd-rcv-bufforce.patch
and it can be found in the queue-4.4 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 Dec 8 07:18:57 CET 2016
From: Eric Dumazet <edumazet@xxxxxxxxxx>
Date: Fri, 2 Dec 2016 09:44:53 -0800
Subject: net: avoid signed overflows for SO_{SND|RCV}BUFFORCE
From: Eric Dumazet <edumazet@xxxxxxxxxx>
[ Upstream commit b98b0bc8c431e3ceb4b26b0dfc8db509518fb290 ]
CAP_NET_ADMIN users should not be allowed to set negative
sk_sndbuf or sk_rcvbuf values, as it can lead to various memory
corruptions, crashes, OOM...
Note that before commit 82981930125a ("net: cleanups in
sock_setsockopt()"), the bug was even more serious, since SO_SNDBUF
and SO_RCVBUF were vulnerable.
This needs to be backported to all known linux kernels.
Again, many thanks to syzkaller team for discovering this gem.
Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Reported-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/core/sock.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -745,7 +745,7 @@ int sock_setsockopt(struct socket *sock,
val = min_t(u32, val, sysctl_wmem_max);
set_sndbuf:
sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
- sk->sk_sndbuf = max_t(u32, val * 2, SOCK_MIN_SNDBUF);
+ sk->sk_sndbuf = max_t(int, val * 2, SOCK_MIN_SNDBUF);
/* Wake up sending tasks if we upped the value. */
sk->sk_write_space(sk);
break;
@@ -781,7 +781,7 @@ set_rcvbuf:
* returning the value we actually used in getsockopt
* is the most desirable behavior.
*/
- sk->sk_rcvbuf = max_t(u32, val * 2, SOCK_MIN_RCVBUF);
+ sk->sk_rcvbuf = max_t(int, val * 2, SOCK_MIN_RCVBUF);
break;
case SO_RCVBUFFORCE:
Patches currently in stable-queue which might be from edumazet@xxxxxxxxxx are
queue-4.4/virtio-net-add-a-missing-synchronize_net.patch
queue-4.4/net-dccp-fix-use-after-free-in-dccp_invalid_packet.patch
queue-4.4/net-avoid-signed-overflows-for-so_-snd-rcv-bufforce.patch
queue-4.4/packet-fix-race-condition-in-packet_set_ring.patch
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