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authorEric Dumazet <edumazet@google.com>2013-05-13 21:25:52 +0000
committerBen Hutchings <ben@decadent.org.uk>2013-06-29 04:06:35 +0100
commitf3baed9f2b83a8e27b509c0afb8dc0e2a20b8f7e (patch)
treef6b039d09f56aae3e0e587ec40a82819d39cabb1
parentc32f3410245d666c5bea0e3b6e1e8aad6091b19f (diff)
tcp: fix tcp_md5_hash_skb_data()
[ Upstream commit 54d27fcb338bd9c42d1dfc5a39e18f6f9d373c2e ] TCP md5 communications fail [1] for some devices, because sg/crypto code assume page offsets are below PAGE_SIZE. This was discovered using mlx4 driver [2], but I suspect loopback might trigger the same bug now we use order-3 pages in tcp_sendmsg() [1] Failure is giving following messages. huh, entered softirq 3 NET_RX ffffffff806ad230 preempt_count 00000100, exited with 00000101? [2] mlx4 driver uses order-2 pages to allocate RX frags Reported-by: Matt Schnall <mischnal@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Bernhard Beck <bbeck@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
-rw-r--r--net/ipv4/tcp.c7
1 files changed, 5 insertions, 2 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index fe381c2d5e97..ec8b4b7ee2e2 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -3037,8 +3037,11 @@ int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *hp,
for (i = 0; i < shi->nr_frags; ++i) {
const struct skb_frag_struct *f = &shi->frags[i];
- struct page *page = skb_frag_page(f);
- sg_set_page(&sg, page, skb_frag_size(f), f->page_offset);
+ unsigned int offset = f->page_offset;
+ struct page *page = skb_frag_page(f) + (offset >> PAGE_SHIFT);
+
+ sg_set_page(&sg, page, skb_frag_size(f),
+ offset_in_page(offset));
if (crypto_hash_update(desc, &sg, skb_frag_size(f)))
return 1;
}