kernel.git/net/ipv6/ip6_output.c, branch linux-6.5.y

ipv6: avoid atomic fragment on GSO packets

2023-11-20T10:56:54Z

[ Upstream commit 03d6c848bfb406e9ef6d9846d759e97beaeea113 ] When the ipv6 stack output a GSO packet, if its gso_size is larger than dst MTU, then all segments would be fragmented. However, it is possible for a GSO packet to have a trailing segment with smaller actual size than both gso_size as well as the MTU, which leads to an "atomic fragment". Atomic fragments are considered harmful in RFC-8021. An Existing report from APNIC also shows that atomic fragments are more likely to be dropped even it is equivalent to a no-op [1]. Add an extra check in the GSO slow output path. For each segment from the original over-sized packet, if it fits with the path MTU, then avoid generating an atomic fragment. Link: https://www.potaroo.net/presentations/2022-03-01-ipv6-frag.pdf [1] Fixes: b210de4f8c97 ("net: ipv6: Validate GSO SKB before finish IPv6 processing") Reported-by: David Wragg Signed-off-by: Yan Zhai Link: https://lore.kernel.org/r/90912e3503a242dca0bc36958b11ed03a2696e5e.1698156966.git.yan@cloudflare.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

net: annotate data-races around sk->sk_tsflags

2023-09-19T10:30:17Z

[ Upstream commit e3390b30a5dfb112e8e802a59c0f68f947b638b2 ] sk->sk_tsflags can be read locklessly, add corresponding annotations. Fixes: b9f40e21ef42 ("net-timestamp: move timestamp flags out of sk_flags") Signed-off-by: Eric Dumazet Cc: Willem de Bruijn Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

lwt: Check LWTUNNEL_XMIT_CONTINUE strictly

2023-09-13T07:53:07Z

[ Upstream commit a171fbec88a2c730b108c7147ac5e7b2f5a02b47 ] LWTUNNEL_XMIT_CONTINUE is implicitly assumed in ip(6)_finish_output2, such that any positive return value from a xmit hook could cause unexpected continue behavior, despite that related skb may have been freed. This could be error-prone for future xmit hook ops. One of the possible errors is to return statuses of dst_output directly. To make the code safer, redefine LWTUNNEL_XMIT_CONTINUE value to distinguish from dst_output statuses and check the continue condition explicitly. Fixes: 3a0af8fd61f9 ("bpf: BPF for lightweight tunnel infrastructure") Suggested-by: Dan Carpenter Signed-off-by: Yan Zhai Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/96b939b85eda00e8df4f7c080f770970a4c5f698.1692326837.git.yan@cloudflare.com Signed-off-by: Sasha Levin

ip, ip6: Fix splice to raw and ping sockets

2023-06-16T18:45:16Z

Splicing to SOCK_RAW sockets may set MSG_SPLICE_PAGES, but in such a case, __ip_append_data() will call skb_splice_from_iter() to access the 'from' data, assuming it to point to a msghdr struct with an iter, instead of using the provided getfrag function to access it. In the case of raw_sendmsg(), however, this is not the case and 'from' will point to a raw_frag_vec struct and raw_getfrag() will be the frag-getting function. A similar issue may occur with rawv6_sendmsg(). Fix this by ignoring MSG_SPLICE_PAGES if getfrag != ip_generic_getfrag as ip_generic_getfrag() expects "from" to be a msghdr*, but the other getfrags don't. Note that this will prevent MSG_SPLICE_PAGES from being effective for udplite. This likely affects ping sockets too. udplite looks like it should be okay as it expects "from" to be a msghdr. Signed-off-by: David Howells Reported-by: syzbot+d8486855ef44506fd675@syzkaller.appspotmail.com Link: https://lore.kernel.org/r/000000000000ae4cbf05fdeb8349@google.com/ Fixes: 2dc334f1a63a ("splice, net: Use sendmsg(MSG_SPLICE_PAGES) rather than ->sendpage()") Tested-by: syzbot+d8486855ef44506fd675@syzkaller.appspotmail.com cc: David Ahern cc: Jens Axboe cc: Matthew Wilcox Reviewed-by: Willem de Bruijn Link: https://lore.kernel.org/r/1410156.1686729856@warthog.procyon.org.uk Signed-off-by: Jakub Kicinski

net: move gso declarations and functions to their own files

2023-06-10T07:11:41Z

Move declarations into include/net/gso.h and code into net/core/gso.c Signed-off-by: Eric Dumazet Cc: Stanislav Fomichev Reviewed-by: Simon Horman Reviewed-by: David Ahern Link: https://lore.kernel.org/r/20230608191738.3947077-1-edumazet@google.com Signed-off-by: Jakub Kicinski

ip6, udp6: Support MSG_SPLICE_PAGES

2023-05-24T03:48:27Z

Make IP6/UDP6 sendmsg() support MSG_SPLICE_PAGES. This causes pages to be spliced from the source iterator if possible, copying the data if not. This allows ->sendpage() to be replaced by something that can handle multiple multipage folios in a single transaction. Signed-off-by: David Howells cc: Willem de Bruijn cc: David Ahern cc: Jens Axboe cc: Matthew Wilcox Signed-off-by: Jakub Kicinski

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

2023-04-06T19:01:20Z

Conflicts: drivers/net/ethernet/google/gve/gve.h 3ce934558097 ("gve: Secure enough bytes in the first TX desc for all TCP pkts") 75eaae158b1b ("gve: Add XDP DROP and TX support for GQI-QPL format") https://lore.kernel.org/all/20230406104927.45d176f5@canb.auug.org.au/ https://lore.kernel.org/all/c5872985-1a95-0bc8-9dcc-b6f23b439e9d@tessares.net/ Adjacent changes: net/can/isotp.c 051737439eae ("can: isotp: fix race between isotp_sendsmg() and isotp_release()") 96d1c81e6a04 ("can: isotp: add module parameter for maximum pdu size") Signed-off-by: Jakub Kicinski

ipv6: Fix an uninit variable access bug in __ip6_make_skb()

2023-04-03T09:17:28Z

Syzbot reported a bug as following: ===================================================== BUG: KMSAN: uninit-value in arch_atomic64_inc arch/x86/include/asm/atomic64_64.h:88 [inline] BUG: KMSAN: uninit-value in arch_atomic_long_inc include/linux/atomic/atomic-long.h:161 [inline] BUG: KMSAN: uninit-value in atomic_long_inc include/linux/atomic/atomic-instrumented.h:1429 [inline] BUG: KMSAN: uninit-value in __ip6_make_skb+0x2f37/0x30f0 net/ipv6/ip6_output.c:1956 arch_atomic64_inc arch/x86/include/asm/atomic64_64.h:88 [inline] arch_atomic_long_inc include/linux/atomic/atomic-long.h:161 [inline] atomic_long_inc include/linux/atomic/atomic-instrumented.h:1429 [inline] __ip6_make_skb+0x2f37/0x30f0 net/ipv6/ip6_output.c:1956 ip6_finish_skb include/net/ipv6.h:1122 [inline] ip6_push_pending_frames+0x10e/0x550 net/ipv6/ip6_output.c:1987 rawv6_push_pending_frames+0xb12/0xb90 net/ipv6/raw.c:579 rawv6_sendmsg+0x297e/0x2e60 net/ipv6/raw.c:922 inet_sendmsg+0x101/0x180 net/ipv4/af_inet.c:827 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg net/socket.c:734 [inline] ____sys_sendmsg+0xa8e/0xe70 net/socket.c:2476 ___sys_sendmsg+0x2a1/0x3f0 net/socket.c:2530 __sys_sendmsg net/socket.c:2559 [inline] __do_sys_sendmsg net/socket.c:2568 [inline] __se_sys_sendmsg net/socket.c:2566 [inline] __x64_sys_sendmsg+0x367/0x540 net/socket.c:2566 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Uninit was created at: slab_post_alloc_hook mm/slab.h:766 [inline] slab_alloc_node mm/slub.c:3452 [inline] __kmem_cache_alloc_node+0x71f/0xce0 mm/slub.c:3491 __do_kmalloc_node mm/slab_common.c:967 [inline] __kmalloc_node_track_caller+0x114/0x3b0 mm/slab_common.c:988 kmalloc_reserve net/core/skbuff.c:492 [inline] __alloc_skb+0x3af/0x8f0 net/core/skbuff.c:565 alloc_skb include/linux/skbuff.h:1270 [inline] __ip6_append_data+0x51c1/0x6bb0 net/ipv6/ip6_output.c:1684 ip6_append_data+0x411/0x580 net/ipv6/ip6_output.c:1854 rawv6_sendmsg+0x2882/0x2e60 net/ipv6/raw.c:915 inet_sendmsg+0x101/0x180 net/ipv4/af_inet.c:827 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg net/socket.c:734 [inline] ____sys_sendmsg+0xa8e/0xe70 net/socket.c:2476 ___sys_sendmsg+0x2a1/0x3f0 net/socket.c:2530 __sys_sendmsg net/socket.c:2559 [inline] __do_sys_sendmsg net/socket.c:2568 [inline] __se_sys_sendmsg net/socket.c:2566 [inline] __x64_sys_sendmsg+0x367/0x540 net/socket.c:2566 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd It is because icmp6hdr does not in skb linear region under the scenario of SOCK_RAW socket. Access icmp6_hdr(skb)->icmp6_type directly will trigger the uninit variable access bug. Use a local variable icmp6_type to carry the correct value in different scenarios. Fixes: 14878f75abd5 ("[IPV6]: Add ICMPMsgStats MIB (RFC 4293) [rev 2]") Reported-by: syzbot+8257f4dcef79de670baf@syzkaller.appspotmail.com Link: https://syzkaller.appspot.com/bug?id=3d605ec1d0a7f2a269a1a6936ac7f2b85975ee9c Signed-off-by: Ziyang Xuan Signed-off-by: David S. Miller

neighbour: switch to standard rcu, instead of rcu_bh

2023-03-22T04:32:18Z

rcu_bh is no longer a win, especially for objects freed with standard call_rcu(). Switch neighbour code to no longer disable BH when not necessary. Signed-off-by: Eric Dumazet Signed-off-by: Jakub Kicinski

neighbour: annotate lockless accesses to n->nud_state

2023-03-15T07:37:32Z

We have many lockless accesses to n->nud_state. Before adding another one in the following patch, add annotations to readers and writers. Signed-off-by: Eric Dumazet Reviewed-by: David Ahern Reviewed-by: Martin KaFai Lau Signed-off-by: Jakub Kicinski