kernel/linux.git/net/ipv6/esp6.c, branch v5.18

esp: limit skb_page_frag_refill use to a single page

2022-04-13T08:16:11+00:00

Commit ebe48d368e97 ("esp: Fix possible buffer overflow in ESP transformation") tried to fix skb_page_frag_refill usage in ESP by capping allocsize to 32k, but that doesn't completely solve the issue, as skb_page_frag_refill may return a single page. If that happens, we will write out of bounds, despite the check introduced in the previous patch. This patch forces COW in cases where we would end up calling skb_page_frag_refill with a size larger than a page (first in esp_output_head with tailen, then in esp_output_tail with skb->data_len). Fixes: cac2661c53f3 ("esp4: Avoid skb_cow_data whenever possible") Fixes: 03e2a30f6a27 ("esp6: Avoid skb_cow_data whenever possible") Signed-off-by: Sabrina Dubroca Signed-off-by: Steffen Klassert

esp6: fix check on ipv6_skip_exthdr's return value

2022-03-14T10:42:27+00:00

Commit 5f9c55c8066b ("ipv6: check return value of ipv6_skip_exthdr") introduced an incorrect check, which leads to all ESP packets over either TCPv6 or UDPv6 encapsulation being dropped. In this particular case, offset is negative, since skb->data points to the ESP header in the following chain of headers, while skb->network_header points to the IPv6 header: IPv6 | ext | ... | ext | UDP | ESP | ... That doesn't seem to be a problem, especially considering that if we reach esp6_input_done2, we're guaranteed to have a full set of headers available (otherwise the packet would have been dropped earlier in the stack). However, it means that the return value will (intentionally) be negative. We can make the test more specific, as the expected return value of ipv6_skip_exthdr will be the (negated) size of either a UDP header, or a TCP header with possible options. In the future, we should probably either make ipv6_skip_exthdr explicitly accept negative offsets (and adjust its return value for error cases), or make ipv6_skip_exthdr only take non-negative offsets (and audit all callers). Fixes: 5f9c55c8066b ("ipv6: check return value of ipv6_skip_exthdr") Reported-by: Xiumei Mu Signed-off-by: Sabrina Dubroca Signed-off-by: Steffen Klassert

esp: Fix possible buffer overflow in ESP transformation

2022-03-07T12:14:03+00:00

The maximum message size that can be send is bigger than the maximum site that skb_page_frag_refill can allocate. So it is possible to write beyond the allocated buffer. Fix this by doing a fallback to COW in that case. v2: Avoid get get_order() costs as suggested by Linus Torvalds. Fixes: cac2661c53f3 ("esp4: Avoid skb_cow_data whenever possible") Fixes: 03e2a30f6a27 ("esp6: Avoid skb_cow_data whenever possible") Reported-by: valis Signed-off-by: Steffen Klassert

Revert "xfrm: xfrm_state_mtu should return at least 1280 for ipv6"

2022-01-27T06:34:06+00:00

This reverts commit b515d2637276a3810d6595e10ab02c13bfd0b63a. Commit b515d2637276a3810d6595e10ab02c13bfd0b63a ("xfrm: xfrm_state_mtu should return at least 1280 for ipv6") in v5.14 breaks the TCP MSS calculation in ipsec transport mode, resulting complete stalls of TCP connections. This happens when the (P)MTU is 1280 or slighly larger. The desired formula for the MSS is: MSS = (MTU - ESP_overhead) - IP header - TCP header However, the above commit clamps the (MTU - ESP_overhead) to a minimum of 1280, turning the formula into MSS = max(MTU - ESP overhead, 1280) - IP header - TCP header With the (P)MTU near 1280, the calculated MSS is too large and the resulting TCP packets never make it to the destination because they are over the actual PMTU. The above commit also causes suboptimal double fragmentation in xfrm tunnel mode, as described in https://lore.kernel.org/netdev/20210429202529.codhwpc7w6kbudug@dwarf.suse.cz/ The original problem the above commit was trying to fix is now fixed by commit 6596a0229541270fb8d38d989f91b78838e5e9da ("xfrm: fix MTU regression"). Signed-off-by: Jiri Bohac Signed-off-by: Steffen Klassert

Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next

2022-01-06T11:54:20+00:00

Steffen Klassert says: ==================== pull request (net-next): ipsec-next 2022-01-06 1) Fix some clang_analyzer warnings about never read variables. From luo penghao. 2) Check for pols[0] only once in xfrm_expand_policies(). From Jean Sacren. 3) The SA curlft.use_time was updated only on SA cration time. Update whenever the SA is used. From Antony Antony 4) Add support for SM3 secure hash. From Xu Jia. 5) Add support for SM4 symmetric cipher algorithm. From Xu Jia. 6) Add a rate limit for SA mapping change messages. From Antony Antony. ==================== Signed-off-by: David S. Miller

ipv6/esp6: Remove structure variables and alignment statements

2021-11-18T18:15:04+00:00

The definition of this variable is just to find the length of the structure after aligning the structure. The PTR alignment function is to optimize the size of the structure. In fact, it doesn't seem to be of much use, because both members of the structure are of type u32. So I think that the definition of the variable and the corresponding alignment can be deleted, the value of extralen can be directly passed in the size of the structure. The clang_analyzer complains as follows: net/ipv6/esp6.c:117:27 warning: Value stored to 'extra' during its initialization is never read Reported-by: Zeal Robot Signed-off-by: luo penghao Signed-off-by: Steffen Klassert

ipv6: check return value of ipv6_skip_exthdr

2021-11-18T11:42:06+00:00

The offset value is used in pointer math on skb->data. Since ipv6_skip_exthdr may return -1 the pointer to uh and th may not point to the actual udp and tcp headers and potentially overwrite other stuff. This is why I think this should be checked. EDIT: added {}'s, thanks Kees Signed-off-by: Jordy Zomer Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2021-06-29T22:45:27+00:00

Trivial conflict in net/netfilter/nf_tables_api.c. Duplicate fix in tools/testing/selftests/net/devlink_port_split.py - take the net-next version. skmsg, and L4 bpf - keep the bpf code but remove the flags and err params. Signed-off-by: Jakub Kicinski

Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec

2021-06-23T19:34:15+00:00

Steffen Klassert says: ==================== pull request (net): ipsec 2021-06-23 1) Don't return a mtu smaller than 1280 on IPv6 pmtu discovery. From Sabrina Dubroca 2) Fix seqcount rcu-read side in xfrm_policy_lookup_bytype for the PREEMPT_RT case. From Varad Gautam. 3) Remove a repeated declaration of xfrm_parse_spi. From Shaokun Zhang. 4) IPv4 beet mode can't handle fragments, but IPv6 does. commit 68dc022d04eb ("xfrm: BEET mode doesn't support fragments for inner packets") handled IPv4 and IPv6 the same way. Relax the check for IPv6 because fragments are possible here. From Xin Long. 5) Memory allocation failures are not reported for XFRMA_ENCAP and XFRMA_COADDR in xfrm_state_construct. Fix this by moving both cases in front of the function. 6) Fix a missing initialization in the xfrm offload fallback fail case for bonding devices. From Ayush Sawal. Please pull or let me know if there are problems. ==================== Signed-off-by: David S. Miller

xfrm: remove hdr_offset indirection

2021-06-11T12:48:50+00:00

After previous patches all remaining users set the function pointer to the same function: xfrm6_find_1stfragopt. So remove this function pointer and call ip6_find_1stfragopt directly. Reduces size of xfrm_type to 64 bytes on 64bit platforms. Signed-off-by: Florian Westphal Signed-off-by: Steffen Klassert