inet: prevent leakage of uninitialized memory to user in recv syscalls
Only update *addr_len when we actually fill in sockaddr, otherwise we can return uninitialized memory from the stack to the caller in the recvfrom, recvmmsg and recvmsg syscalls. Drop the the (addr_len == NULL) checks because we only get called with a valid addr_len pointer either from sock_common_recvmsg or inet_recvmsg. If a blocking read waits on a socket which is concurrently shut down we now return zero and set msg_msgnamelen to 0. Reported-by: mpb <mpb.mail@gmail.com> Suggested-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
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David S. Miller

parent
bcd081a3ae
commit
bceaa90240
@@ -315,9 +315,8 @@ static int dgram_recvmsg(struct kiocb *iocb, struct sock *sk,
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if (saddr) {
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saddr->family = AF_IEEE802154;
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saddr->addr = mac_cb(skb)->sa;
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}
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if (addr_len)
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*addr_len = sizeof(*saddr);
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}
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if (flags & MSG_TRUNC)
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copied = skb->len;
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