linux/net/ipv4, branch v3.0.21

net: fix NULL dereferences in check_peer_redir()

2012-02-13T19:06:13Z

[ Upstream commit d3aaeb38c40e5a6c08dd31a1b64da65c4352be36, along with dependent backports of commits: 69cce1d1404968f78b177a0314f5822d5afdbbfb 9de79c127cccecb11ae6a21ab1499e87aa222880 218fa90f072e4aeff9003d57e390857f4f35513e 580da35a31f91a594f3090b7a2c39b85cb051a12 f7e57044eeb1841847c24aa06766c8290c202583 e049f28883126c689cf95859480d9ee4ab23b7fa ] Gergely Kalman reported crashes in check_peer_redir(). It appears commit f39925dbde778 (ipv4: Cache learned redirect information in inetpeer.) added a race, leading to possible NULL ptr dereference. Since we can now change dst neighbour, we should make sure a reader can safely use a neighbour. Add RCU protection to dst neighbour, and make sure check_peer_redir() can be called safely by different cpus in parallel. As neighbours are already freed after one RCU grace period, this patch should not add typical RCU penalty (cache cold effects) Many thanks to Gergely for providing a pretty report pointing to the bug. Reported-by: Gergely Kalman Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

tcp: md5: using remote adress for md5 lookup in rst packet

2012-02-03T17:19:04Z

[ Upstream commit 8a622e71f58ec9f092fc99eacae0e6cf14f6e742 ] md5 key is added in socket through remote address. remote address should be used in finding md5 key when sending out reset packet. Signed-off-by: shawnlu Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

tcp: fix tcp_trim_head() to adjust segment count with skb MSS

2012-02-03T17:19:04Z

[ Upstream commit 5b35e1e6e9ca651e6b291c96d1106043c9af314a ] This commit fixes tcp_trim_head() to recalculate the number of segments in the skb with the skb's existing MSS, so trimming the head causes the skb segment count to be monotonically non-increasing - it should stay the same or go down, but not increase. Previously tcp_trim_head() used the current MSS of the connection. But if there was a decrease in MSS between original transmission and ACK (e.g. due to PMTUD), this could cause tcp_trim_head() to counter-intuitively increase the segment count when trimming bytes off the head of an skb. This violated assumptions in tcp_tso_acked() that tcp_trim_head() only decreases the packet count, so that packets_acked in tcp_tso_acked() could underflow, leading tcp_clean_rtx_queue() to pass u32 pkts_acked values as large as 0xffffffff to ca_ops->pkts_acked(). As an aside, if tcp_trim_head() had really wanted the skb to reflect the current MSS, it should have called tcp_set_skb_tso_segs() unconditionally, since a decrease in MSS would mean that a single-packet skb should now be sliced into multiple segments. Signed-off-by: Neal Cardwell Acked-by: Nandita Dukkipati Acked-by: Ilpo Järvinen Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

ah: Don't return NET_XMIT_DROP on input.

2012-02-03T17:18:54Z

commit 4b90a603a1b21d63cf743cc833680cb195a729f6 upstream. When the ahash driver returns -EBUSY, AH4/6 input functions return NET_XMIT_DROP, presumably copied from the output code path. But returning transmit codes on input doesn't make a lot of sense. Since NET_XMIT_DROP is a positive int, this gets interpreted as the next header type (i.e., success). As that can only end badly, remove the check. Signed-off-by: Nick Bowler Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

ah: Read nexthdr value before overwriting it in ahash input callback.

2012-01-26T01:24:51Z

commit b7ea81a58adc123a4e980cb0eff9eb5c144b5dc7 upstream. The AH4/6 ahash input callbacks read out the nexthdr field from the AH header *after* they overwrite that header. This is obviously not going to end well. Fix it up. Signed-off-by: Nick Bowler Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

ah: Correctly pass error codes in ahash output callback.

2012-01-26T01:24:51Z

commit 069294e813ed5f27f82613b027609bcda5f1b914 upstream. The AH4/6 ahash output callbacks pass nexthdr to xfrm_output_resume instead of the error code. This appears to be a copy+paste error from the input case, where nexthdr is expected. This causes the driver to continuously add AH headers to the datagram until either an allocation fails and the packet is dropped or the ahash driver hits a synchronous fallback and the resulting monstrosity is transmitted. Correct this issue by simply passing the error code unadulterated. Signed-off-by: Nick Bowler Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

igmp: Avoid zero delay when receiving odd mixture of IGMP queries

2012-01-12T19:35:41Z

commit a8c1f65c79cbbb2f7da782d4c9d15639a9b94b27 upstream. Commit 5b7c84066733c5dfb0e4016d939757b38de189e4 ('ipv4: correct IGMP behavior on v3 query during v2-compatibility mode') added yet another case for query parsing, which can result in max_delay = 0. Substitute a value of 1, as in the usual v3 case. Reported-by: Simon McVittie References: http://bugs.debian.org/654876 Signed-off-by: Ben Hutchings Signed-off-by: David S. Miller

ipv4: using prefetch requires including prefetch.h

2012-01-06T22:14:10Z

[ Upstream commit b9eda06f80b0db61a73bd87c6b0eb67d8aca55ad ] Signed-off-by: Stephen Rothwell Acked-by: Eric Dumazet Acked-by: David Miller Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

ipv4: reintroduce route cache garbage collector

2012-01-06T22:14:10Z

[ Upstream commit 9f28a2fc0bd77511f649c0a788c7bf9a5fd04edb ] Commit 2c8cec5c10b (ipv4: Cache learned PMTU information in inetpeer) removed IP route cache garbage collector a bit too soon, as this gc was responsible for expired routes cleanup, releasing their neighbour reference. As pointed out by Robert Gladewitz, recent kernels can fill and exhaust their neighbour cache. Reintroduce the garbage collection, since we'll have to wait our neighbour lookups become refcount-less to not depend on this stuff. Reported-by: Robert Gladewitz Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

ipv4: flush route cache after change accept_local

2012-01-06T22:14:09Z

[ Upstream commit d01ff0a049f749e0bf10a35bb23edd012718c8c2 ] After reset ipv4_devconf->data[IPV4_DEVCONF_ACCEPT_LOCAL] to 0, we should flush route cache, or it will continue receive packets with local source address, which should be dropped. Signed-off-by: Weiping Pan Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman