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authorXin Long <lucien.xin@gmail.com>2021-07-23 18:46:01 -0400
committerDavid S. Miller <davem@davemloft.net>2021-07-24 19:38:21 +0100
commit3cf4375a090473d240281a0d2b04a3a5aaeac34b (patch)
treea67b457aa6b5406e026c9aa110fcecba15904ff0
parente394f1e3b13946b200935310ebdd5583cf374bba (diff)
tipc: do not write skb_shinfo frags when doing decrytion
One skb's skb_shinfo frags are not writable, and they can be shared with other skbs' like by pskb_copy(). To write the frags may cause other skb's data crash. So before doing en/decryption, skb_cow_data() should always be called for a cloned or nonlinear skb if req dst is using the same sg as req src. While at it, the likely branch can be removed, as it will be covered by skb_cow_data(). Note that esp_input() has the same issue, and I will fix it in another patch. tipc_aead_encrypt() doesn't have this issue, as it only processes linear data in the unlikely branch. Fixes: fc1b6d6de220 ("tipc: introduce TIPC encryption & authentication") Reported-by: Shuang Li <shuali@redhat.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Jon Maloy <jmaloy@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--net/tipc/crypto.c14
1 files changed, 4 insertions, 10 deletions
diff --git a/net/tipc/crypto.c b/net/tipc/crypto.c
index e5c43d4d5a75..c9391d38de85 100644
--- a/net/tipc/crypto.c
+++ b/net/tipc/crypto.c
@@ -898,16 +898,10 @@ static int tipc_aead_decrypt(struct net *net, struct tipc_aead *aead,
if (unlikely(!aead))
return -ENOKEY;
- /* Cow skb data if needed */
- if (likely(!skb_cloned(skb) &&
- (!skb_is_nonlinear(skb) || !skb_has_frag_list(skb)))) {
- nsg = 1 + skb_shinfo(skb)->nr_frags;
- } else {
- nsg = skb_cow_data(skb, 0, &unused);
- if (unlikely(nsg < 0)) {
- pr_err("RX: skb_cow_data() returned %d\n", nsg);
- return nsg;
- }
+ nsg = skb_cow_data(skb, 0, &unused);
+ if (unlikely(nsg < 0)) {
+ pr_err("RX: skb_cow_data() returned %d\n", nsg);
+ return nsg;
}
/* Allocate memory for the AEAD operation */