kernel/git/stable/linux.git/net/ipv6, branch linux-5.16.y

ipv6: Fix stats accounting in ip6_pkt_drop

2022-04-13T18:03:16+00:00

[ Upstream commit 1158f79f82d437093aeed87d57df0548bdd68146 ] VRF devices are the loopbacks for VRFs, and a loopback can not be assigned to a VRF. Accordingly, the condition in ip6_pkt_drop should be '||' not '&&'. Fixes: 1d3fd8a10bed ("vrf: Use orig netdev to count Ip6InNoRoutes and a fresh route lookup when sending dest unreach") Reported-by: Pudak, Filip Reported-by: Xiao, Jiguang Signed-off-by: David Ahern Link: https://lore.kernel.org/r/20220404150908.2937-1-dsahern@kernel.org Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

tcp: Don't acquire inet_listen_hashbucket::lock with disabled BH.

2022-04-13T18:03:01+00:00

[ Upstream commit 4f9bf2a2f5aacf988e6d5e56b961ba45c5a25248 ] Commit 9652dc2eb9e40 ("tcp: relax listening_hash operations") removed the need to disable bottom half while acquiring listening_hash.lock. There are still two callers left which disable bottom half before the lock is acquired. On PREEMPT_RT the softirqs are preemptible and local_bh_disable() acts as a lock to ensure that resources, that are protected by disabling bottom halves, remain protected. This leads to a circular locking dependency if the lock acquired with disabled bottom halves is also acquired with enabled bottom halves followed by disabling bottom halves. This is the reverse locking order. It has been observed with inet_listen_hashbucket::lock: local_bh_disable() + spin_lock(&ilb->lock): inet_listen() inet_csk_listen_start() sk->sk_prot->hash() := inet_hash() local_bh_disable() __inet_hash() spin_lock(&ilb->lock); acquire(&ilb->lock); Reverse order: spin_lock(&ilb2->lock) + local_bh_disable(): tcp_seq_next() listening_get_next() spin_lock(&ilb2->lock); acquire(&ilb2->lock); tcp4_seq_show() get_tcp4_sock() sock_i_ino() read_lock_bh(&sk->sk_callback_lock); acquire(softirq_ctrl) // <---- whoops acquire(&sk->sk_callback_lock) Drop local_bh_disable() around __inet_hash() which acquires listening_hash->lock. Split inet_unhash() and acquire the listen_hashbucket lock without disabling bottom halves; the inet_ehash lock with disabled bottom halves. Reported-by: Mike Galbraith Signed-off-by: Sebastian Andrzej Siewior Link: https://lkml.kernel.org/r/12d6f9879a97cd56c09fb53dee343cbb14f7f1f7.camel@gmx.de Link: https://lkml.kernel.org/r/X9CheYjuXWc75Spa@hirez.programming.kicks-ass.net Link: https://lore.kernel.org/r/YgQOebeZ10eNx1W6@linutronix.de Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

ipv6: make mc_forwarding atomic

2022-04-13T18:03:00+00:00

[ Upstream commit 145c7a793838add5e004e7d49a67654dc7eba147 ] This fixes minor data-races in ip6_mc_input() and batadv_mcast_mla_rtr_flags_softif_get_ipv6() Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

xfrm: fix tunnel model fragmentation behavior

2022-04-08T12:05:17+00:00

[ Upstream commit 4ff2980b6bd2aa6b4ded3ce3b7c0ccfab29980af ] in tunnel mode, if outer interface(ipv4) is less, it is easily to let inner IPV6 mtu be less than 1280. If so, a Packet Too Big ICMPV6 message is received. When send again, packets are fragmentized with 1280, they are still rejected with ICMPV6(Packet Too Big) by xfrmi_xmit2(). According to RFC4213 Section3.2.2: if (IPv4 path MTU - 20) is less than 1280 if packet is larger than 1280 bytes Send ICMPv6 "packet too big" with MTU=1280 Drop packet else Encapsulate but do not set the Don't Fragment flag in the IPv4 header. The resulting IPv4 packet might be fragmented by the IPv4 layer on the encapsulator or by some router along the IPv4 path. endif else if packet is larger than (IPv4 path MTU - 20) Send ICMPv6 "packet too big" with MTU = (IPv4 path MTU - 20). Drop packet. else Encapsulate and set the Don't Fragment flag in the IPv4 header. endif endif Packets should be fragmentized with ipv4 outer interface, so change it. After it is fragemtized with ipv4, there will be double fragmenation. No.48 & No.51 are ipv6 fragment packets, No.48 is double fragmentized, then tunneled with IPv4(No.49& No.50), which obey spec. And received peer cannot decrypt it rightly. 48 2002::10 2002::11 1296(length) IPv6 fragment (off=0 more=y ident=0xa20da5bc nxt=50) 49 0x0000 (0) 2002::10 2002::11 1304 IPv6 fragment (off=0 more=y ident=0x7448042c nxt=44) 50 0x0000 (0) 2002::10 2002::11 200 ESP (SPI=0x00035000) 51 2002::10 2002::11 180 Echo (ping) request 52 0x56dc 2002::10 2002::11 248 IPv6 fragment (off=1232 more=n ident=0xa20da5bc nxt=50) xfrm6_noneed_fragment has fixed above issues. Finally, it acted like below: 1 0x6206 192.168.1.138 192.168.1.1 1316 Fragmented IP protocol (proto=Encap Security Payload 50, off=0, ID=6206) [Reassembled in #2] 2 0x6206 2002::10 2002::11 88 IPv6 fragment (off=0 more=y ident=0x1f440778 nxt=50) 3 0x0000 2002::10 2002::11 248 ICMPv6 Echo (ping) request Signed-off-by: Lina Wang Signed-off-by: Steffen Klassert Signed-off-by: Sasha Levin

net: ipv6: fix skb_over_panic in __ip6_append_data

2022-03-28T07:59:54+00:00

commit 5e34af4142ffe68f01c8a9acae83300f8911e20c upstream. Syzbot found a kernel bug in the ipv6 stack: LINK: https://syzkaller.appspot.com/bug?id=205d6f11d72329ab8d62a610c44c5e7e25415580 The reproducer triggers it by sending a crafted message via sendmmsg() call, which triggers skb_over_panic, and crashes the kernel: skbuff: skb_over_panic: text:ffffffff84647fb4 len:65575 put:65575 head:ffff888109ff0000 data:ffff888109ff0088 tail:0x100af end:0xfec0 dev: Update the check that prevents an invalid packet with MTU equal to the fregment header size to eat up all the space for payload. The reproducer can be found here: LINK: https://syzkaller.appspot.com/text?tag=ReproC&x=1648c83fb00000 Reported-by: syzbot+e223cf47ec8ae183f2a0@syzkaller.appspotmail.com Signed-off-by: Tadeusz Struk Acked-by: Willem de Bruijn Link: https://lore.kernel.org/r/20220310232538.1044947-1-tadeusz.struk@linaro.org Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

esp6: fix check on ipv6_skip_exthdr's return value

2022-03-23T08:18:47+00:00

[ Upstream commit 4db4075f92af2b28f415fc979ab626e6b37d67b6 ] 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 Signed-off-by: Sasha Levin

ipv6: prevent a possible race condition with lifetimes

2022-03-16T13:26:48+00:00

[ Upstream commit 6c0d8833a605e195ae219b5042577ce52bf71fff ] valid_lft, prefered_lft and tstamp are always accessed under the lock "lock" in other places. Reading these without taking the lock may result in inconsistencies regarding the calculation of the valid and preferred variables since decisions are taken on these fields for those variables. Signed-off-by: Niels Dossche Reviewed-by: David Ahern Signed-off-by: Niels Dossche Link: https://lore.kernel.org/r/20220223131954.6570-1-niels.dossche@ugent.be Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

esp: Fix BEET mode inter address family tunneling on GSO

2022-03-16T13:26:42+00:00

[ Upstream commit 053c8fdf2c930efdff5496960842bbb5c34ad43a ] The xfrm{4,6}_beet_gso_segment() functions did not correctly set the SKB_GSO_IPXIP4 and SKB_GSO_IPXIP6 gso types for the address family tunneling case. Fix this by setting these gso types. Fixes: 384a46ea7bdc7 ("esp4: add gso_segment for esp4 beet mode") Fixes: 7f9e40eb18a99 ("esp6: add gso_segment for esp6 beet mode") Signed-off-by: Steffen Klassert Signed-off-by: Sasha Levin

esp: Fix possible buffer overflow in ESP transformation

2022-03-16T13:26:42+00:00

[ Upstream commit ebe48d368e97d007bfeb76fcb065d6cfc4c96645 ] 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 Signed-off-by: Sasha Levin

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

2022-03-08T18:14:19+00:00

commit a6d95c5a628a09be129f25d5663a7e9db8261f51 upstream. 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 Signed-off-by: Greg Kroah-Hartman