kernel.git/net/core/sock.c, branch linux-3.16.y

net: Set sk_prot_creator when cloning sockets to the right proto

2018-09-25T22:47:21Z

commit 9d538fa60bad4f7b23193c89e843797a1cf71ef3 upstream. sk->sk_prot and sk->sk_prot_creator can differ when the app uses IPV6_ADDRFORM (transforming an IPv6-socket to an IPv4-one). Which is why sk_prot_creator is there to make sure that sk_prot_free() does the kmem_cache_free() on the right kmem_cache slab. Now, if such a socket gets transformed back to a listening socket (using connect() with AF_UNSPEC) we will allocate an IPv4 tcp_sock through sk_clone_lock() when a new connection comes in. But sk_prot_creator will still point to the IPv6 kmem_cache (as everything got copied in sk_clone_lock()). When freeing, we will thus put this memory back into the IPv6 kmem_cache although it was allocated in the IPv4 cache. I have seen memory corruption happening because of this. With slub-debugging and MEMCG_KMEM enabled this gives the warning "cache_from_obj: Wrong slab cache. TCPv6 but object is from TCP" A C-program to trigger this: void main(void) { int fd = socket(AF_INET6, SOCK_STREAM, IPPROTO_TCP); int new_fd, newest_fd, client_fd; struct sockaddr_in6 bind_addr; struct sockaddr_in bind_addr4, client_addr1, client_addr2; struct sockaddr unsp; int val; memset(&bind_addr, 0, sizeof(bind_addr)); bind_addr.sin6_family = AF_INET6; bind_addr.sin6_port = ntohs(42424); memset(&client_addr1, 0, sizeof(client_addr1)); client_addr1.sin_family = AF_INET; client_addr1.sin_port = ntohs(42424); client_addr1.sin_addr.s_addr = inet_addr("127.0.0.1"); memset(&client_addr2, 0, sizeof(client_addr2)); client_addr2.sin_family = AF_INET; client_addr2.sin_port = ntohs(42421); client_addr2.sin_addr.s_addr = inet_addr("127.0.0.1"); memset(&unsp, 0, sizeof(unsp)); unsp.sa_family = AF_UNSPEC; bind(fd, (struct sockaddr *)&bind_addr, sizeof(bind_addr)); listen(fd, 5); client_fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP); connect(client_fd, (struct sockaddr *)&client_addr1, sizeof(client_addr1)); new_fd = accept(fd, NULL, NULL); close(fd); val = AF_INET; setsockopt(new_fd, SOL_IPV6, IPV6_ADDRFORM, &val, sizeof(val)); connect(new_fd, &unsp, sizeof(unsp)); memset(&bind_addr4, 0, sizeof(bind_addr4)); bind_addr4.sin_family = AF_INET; bind_addr4.sin_port = ntohs(42421); bind(new_fd, (struct sockaddr *)&bind_addr4, sizeof(bind_addr4)); listen(new_fd, 5); client_fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP); connect(client_fd, (struct sockaddr *)&client_addr2, sizeof(client_addr2)); newest_fd = accept(new_fd, NULL, NULL); close(new_fd); close(client_fd); close(new_fd); } As far as I can see, this bug has been there since the beginning of the git-days. Signed-off-by: Christoph Paasch Reviewed-by: Eric Dumazet Signed-off-by: David S. Miller Cc: Thomas King Signed-off-by: Ben Hutchings

net: fix compile error in skb_orphan_partial()

2017-09-15T17:29:43Z

commit 9142e9007f2d7ab58a587a1e1d921b0064a339aa upstream. If CONFIG_INET is not set, net/core/sock.c can not compile : net/core/sock.c: In function ‘skb_orphan_partial’: net/core/sock.c:1810:2: error: implicit declaration of function ‘skb_is_tcp_pure_ack’ [-Werror=implicit-function-declaration] if (skb_is_tcp_pure_ack(skb)) ^ Fix this by always including Fixes: f6ba8d33cfbb ("netem: fix skb_orphan_partial()") Signed-off-by: Eric Dumazet Reported-by: Paul Gortmaker Reported-by: Randy Dunlap Reported-by: Stephen Rothwell Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings

netem: fix skb_orphan_partial()

2017-09-15T17:29:34Z

commit f6ba8d33cfbb46df569972e64dbb5bb7e929bfd9 upstream. I should have known that lowering skb->truesize was dangerous :/ In case packets are not leaving the host via a standard Ethernet device, but looped back to local sockets, bad things can happen, as reported by Michael Madsen ( https://bugzilla.kernel.org/show_bug.cgi?id=195713 ) So instead of tweaking skb->truesize, lets change skb->destructor and keep a reference on the owner socket via its sk_refcnt. Fixes: f2f872f9272a ("netem: Introduce skb_orphan_partial() helper") Signed-off-by: Eric Dumazet Reported-by: Michael Madsen Signed-off-by: David S. Miller [bwh: Backported to 3.16: drop changes to the preceding comment and the fast path, which we don't have] Signed-off-by: Ben Hutchings

net: properly release sk_frag.page

2017-07-18T17:40:15Z

commit 22a0e18eac7a9e986fec76c60fa4a2926d1291e2 upstream. I mistakenly added the code to release sk->sk_frag in sk_common_release() instead of sk_destruct() TCP sockets using sk->sk_allocation == GFP_ATOMIC do no call sk_common_release() at close time, thus leaking one (order-3) page. iSCSI is using such sockets. Fixes: 5640f7685831 ("net: use a per task frag allocator") Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings

net: clear sk_err_soft in sk_clone_lock()

2017-03-16T02:27:19Z

[ Upstream commit e551c32d57c88923f99f8f010e89ca7ed0735e83 ] At accept() time, it is possible the parent has a non zero sk_err_soft, leftover from a prior error. Make sure we do not leave this value in the child, as it makes future getsockopt(SO_ERROR) calls quite unreliable. Signed-off-by: Eric Dumazet Acked-by: Soheil Hassas Yeganeh Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings

net: fix sk_mem_reclaim_partial()

2017-03-16T02:27:18Z

commit 1a24e04e4b50939daa3041682b38b82c896ca438 upstream. sk_mem_reclaim_partial() goal is to ensure each socket has one SK_MEM_QUANTUM forward allocation. This is needed both for performance and better handling of memory pressure situations in follow up patches. SK_MEM_QUANTUM is currently a page, but might be reduced to 4096 bytes as some arches have 64KB pages. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings

net/sock: Add sock_efree() function

2017-03-16T02:27:13Z

Extracted from commit 62bccb8cdb69 ("net-timestamp: Make the clone operation stand-alone from phy timestamping"). Signed-off-by: Ben Hutchings

net: avoid signed overflows for SO_{SND|RCV}BUFFORCE

2017-02-23T03:54:47Z

commit b98b0bc8c431e3ceb4b26b0dfc8db509518fb290 upstream. CAP_NET_ADMIN users should not be allowed to set negative sk_sndbuf or sk_rcvbuf values, as it can lead to various memory corruptions, crashes, OOM... Note that before commit 82981930125a ("net: cleanups in sock_setsockopt()"), the bug was even more serious, since SO_SNDBUF and SO_RCVBUF were vulnerable. This needs to be backported to all known linux kernels. Again, many thanks to syzkaller team for discovering this gem. Signed-off-by: Eric Dumazet Reported-by: Andrey Konovalov Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings

dccp: limit sk_filter trim to payload

2017-02-23T03:54:46Z

commit 4f0c40d94461cfd23893a17335b2ab78ecb333c8 upstream. Dccp verifies packet integrity, including length, at initial rcv in dccp_invalid_packet, later pulls headers in dccp_enqueue_skb. A call to sk_filter in-between can cause __skb_pull to wrap skb->len. skb_copy_datagram_msg interprets this as a negative value, so (correctly) fails with EFAULT. The negative length is reported in ioctl SIOCINQ or possibly in a DCCP_WARN in dccp_close. Introduce an sk_receive_skb variant that caps how small a filter program can trim packets, and call this in dccp with the header length. Excessively trimmed packets are now processed normally and queued for reception as 0B payloads. Fixes: 7c657876b63c ("[DCCP]: Initial implementation") Signed-off-by: Willem de Bruijn Acked-by: Daniel Borkmann Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings

net: Add __sock_queue_rcv_skb()

2017-02-23T03:54:46Z

Extraxcted from commit e6afc8ace6dd5cef5e812f26c72579da8806f5ac "udp: remove headers from UDP packets before queueing". Signed-off-by: Ben Hutchings