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authorAntonio Messina <amessina@google.com>2019-12-19 17:08:03 +0300
committerDavid S. Miller <davem@davemloft.net>2019-12-25 01:52:39 +0300
commitfeed8a4fc9d46c3126fb9fcae0e9248270c6321a (patch)
treeaf3b520fba6a979b12c0fb470dc697a827725b06 /net/ipv4/udp.c
parentc60174717544aa8959683d7e19d568309c3a0c65 (diff)
downloadlinux-feed8a4fc9d46c3126fb9fcae0e9248270c6321a.tar.xz
udp: fix integer overflow while computing available space in sk_rcvbuf
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@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/udp.c')
-rw-r--r--net/ipv4/udp.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 4da5758cc718..93a355b6b092 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -1475,7 +1475,7 @@ int __udp_enqueue_schedule_skb(struct sock *sk, struct sk_buff *skb)
* 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);