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authorOctavian Purdila <opurdila@ixiacom.com>2010-12-16 14:26:56 -0800
committerDavid S. Miller <davem@davemloft.net>2010-12-16 14:26:56 -0800
commitfcbdf09d9652c8919dcf47072e3ae7dcb4eb98ac (patch)
tree51e3cc1fbd813a880ea09dc31a12683b73d87e05 /net/core
parent2984961c388381c1830f95e1c2dc2137301b1009 (diff)
net: fix nulls list corruptions in sk_prot_alloc
Special care is taken inside sk_port_alloc to avoid overwriting skc_node/skc_nulls_node. We should also avoid overwriting skc_bind_node/skc_portaddr_node. The patch fixes the following crash: BUG: unable to handle kernel paging request at fffffffffffffff0 IP: [<ffffffff812ec6dd>] udp4_lib_lookup2+0xad/0x370 [<ffffffff812ecc22>] __udp4_lib_lookup+0x282/0x360 [<ffffffff812ed63e>] __udp4_lib_rcv+0x31e/0x700 [<ffffffff812bba45>] ? ip_local_deliver_finish+0x65/0x190 [<ffffffff812bbbf8>] ? ip_local_deliver+0x88/0xa0 [<ffffffff812eda35>] udp_rcv+0x15/0x20 [<ffffffff812bba45>] ip_local_deliver_finish+0x65/0x190 [<ffffffff812bbbf8>] ip_local_deliver+0x88/0xa0 [<ffffffff812bb2cd>] ip_rcv_finish+0x32d/0x6f0 [<ffffffff8128c14c>] ? netif_receive_skb+0x99c/0x11c0 [<ffffffff812bb94b>] ip_rcv+0x2bb/0x350 [<ffffffff8128c14c>] netif_receive_skb+0x99c/0x11c0 Signed-off-by: Leonard Crestez <lcrestez@ixiacom.com> Signed-off-by: Octavian Purdila <opurdila@ixiacom.com> Acked-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core')
-rw-r--r--net/core/sock.c47
1 files changed, 35 insertions, 12 deletions
diff --git a/net/core/sock.c b/net/core/sock.c
index fb608011146..e5af8d5d5b5 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1009,6 +1009,36 @@ static void sock_copy(struct sock *nsk, const struct sock *osk)
#endif
}
+/*
+ * caches using SLAB_DESTROY_BY_RCU should let .next pointer from nulls nodes
+ * un-modified. Special care is taken when initializing object to zero.
+ */
+static inline void sk_prot_clear_nulls(struct sock *sk, int size)
+{
+ if (offsetof(struct sock, sk_node.next) != 0)
+ memset(sk, 0, offsetof(struct sock, sk_node.next));
+ memset(&sk->sk_node.pprev, 0,
+ size - offsetof(struct sock, sk_node.pprev));
+}
+
+void sk_prot_clear_portaddr_nulls(struct sock *sk, int size)
+{
+ unsigned long nulls1, nulls2;
+
+ nulls1 = offsetof(struct sock, __sk_common.skc_node.next);
+ nulls2 = offsetof(struct sock, __sk_common.skc_portaddr_node.next);
+ if (nulls1 > nulls2)
+ swap(nulls1, nulls2);
+
+ if (nulls1 != 0)
+ memset((char *)sk, 0, nulls1);
+ memset((char *)sk + nulls1 + sizeof(void *), 0,
+ nulls2 - nulls1 - sizeof(void *));
+ memset((char *)sk + nulls2 + sizeof(void *), 0,
+ size - nulls2 - sizeof(void *));
+}
+EXPORT_SYMBOL(sk_prot_clear_portaddr_nulls);
+
static struct sock *sk_prot_alloc(struct proto *prot, gfp_t priority,
int family)
{
@@ -1021,19 +1051,12 @@ static struct sock *sk_prot_alloc(struct proto *prot, gfp_t priority,
if (!sk)
return sk;
if (priority & __GFP_ZERO) {
- /*
- * caches using SLAB_DESTROY_BY_RCU should let
- * sk_node.next un-modified. Special care is taken
- * when initializing object to zero.
- */
- if (offsetof(struct sock, sk_node.next) != 0)
- memset(sk, 0, offsetof(struct sock, sk_node.next));
- memset(&sk->sk_node.pprev, 0,
- prot->obj_size - offsetof(struct sock,
- sk_node.pprev));
+ if (prot->clear_sk)
+ prot->clear_sk(sk, prot->obj_size);
+ else
+ sk_prot_clear_nulls(sk, prot->obj_size);
}
- }
- else
+ } else
sk = kmalloc(prot->obj_size, priority);
if (sk != NULL) {