net/tls: Set count of SG entries if sk_alloc_sg returns -ENOSPC

tls_sw_sendmsg() allocates plaintext and encrypted SG entries using function sk_alloc_sg(). In case the number of SG entries hit MAX_SKB_FRAGS, sk_alloc_sg() returns -ENOSPC and sets the variable for current SG index to '0'. This leads to calling of function tls_push_record() with 'sg_encrypted_num_elem = 0' and later causes kernel crash. To fix this, set the number of SG elements to the number of elements in plaintext/encrypted SG arrays in case sk_alloc_sg() returns -ENOSPC. Fixes: 3c4d755 ("tls: kernel TLS support") Signed-off-by: Vakul Garg <[email protected]> Signed-off-by: David S. Miller <[email protected]>
c-sky · Sep 9, 2018 · 52ea992 · 52ea992
1 parent 0e1f4c7
commit 52ea992
Showing 1 changed file with 6 additions and 0 deletions.
diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c
@@ -125,6 +125,9 @@ static int alloc_encrypted_sg(struct sock *sk, int len)
 			 &ctx->sg_encrypted_num_elem,
 			 &ctx->sg_encrypted_size, 0);
 
+	if (rc == -ENOSPC)
+		ctx->sg_encrypted_num_elem = ARRAY_SIZE(ctx->sg_encrypted_data);
+
 	return rc;
 }
 
@@ -138,6 +141,9 @@ static int alloc_plaintext_sg(struct sock *sk, int len)
 			 &ctx->sg_plaintext_num_elem, &ctx->sg_plaintext_size,
 			 tls_ctx->pending_open_record_frags);
 
+	if (rc == -ENOSPC)
+		ctx->sg_plaintext_num_elem = ARRAY_SIZE(ctx->sg_plaintext_data);
+
 	return rc;
 }