kernel.git/net/ipv4/udp.c, branch linux-2.6.32.y

udp: properly support MSG_PEEK with truncated buffers

2016-01-29T21:12:41Z

commit 197c949e7798fbf28cfadc69d9ca0c2abbf93191 upstream. Backport of this upstream commit into stable kernels : 89c22d8c3b27 ("net: Fix skb csum races when peeking") exposed a bug in udp stack vs MSG_PEEK support, when user provides a buffer smaller than skb payload. In this case, skb_copy_and_csum_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov); returns -EFAULT. This bug does not happen in upstream kernels since Al Viro did a great job to replace this into : skb_copy_and_csum_datagram_msg(skb, sizeof(struct udphdr), msg); This variant is safe vs short buffers. For the time being, instead reverting Herbert Xu patch and add back skb->ip_summed invalid changes, simply store the result of udp_lib_checksum_complete() so that we avoid computing the checksum a second time, and avoid the problematic skb_copy_and_csum_datagram_iovec() call. This patch can be applied on recent kernels as it avoids a double checksumming, then backported to stable kernels as a bug fix. Signed-off-by: Eric Dumazet Acked-by: Herbert Xu Signed-off-by: David S. Miller [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings (cherry picked from commit 18a6eba2eabbcb50a78210b16f7dd43d888a537b) Signed-off-by: Willy Tarreau

Revert "net: add length argument to skb_copy_and_csum_datagram_iovec"

2016-01-29T21:12:40Z

This reverts commit c507639ba963bb47e3f515670a7cace76af76ab6. As reported by Michal Kubecek, this fix doesn't handle truncated reads correctly. Next patch from Eric fixes it better. Signed-off-by: Willy Tarreau

net: add length argument to skb_copy_and_csum_datagram_iovec

2015-12-05T23:49:13Z

Without this length argument, we can read past the end of the iovec in memcpy_toiovec because we have no way of knowing the total length of the iovec's buffers. This is needed for stable kernels where 89c22d8c3b27 ("net: Fix skb csum races when peeking") has been backported but that don't have the ioviter conversion, which is almost all the stable trees <= 3.18. This also fixes a kernel crash for NFS servers when the client uses -onfsvers=3,proto=udp to mount the export. Signed-off-by: Sabrina Dubroca Reviewed-by: Hannes Frederic Sowa [bwh: Backported to 3.2: adjust context in include/linux/skbuff.h] Signed-off-by: Ben Hutchings (cherry picked from commit 127500d724f8c43f452610c9080444eedb5eaa6c) Signed-off-by: Willy Tarreau

udp: fix behavior of wrong checksums

2015-09-18T11:51:57Z

commit beb39db59d14990e401e235faf66a6b9b31240b0 upstream. We have two problems in UDP stack related to bogus checksums : 1) We return -EAGAIN to application even if receive queue is not empty. This breaks applications using edge trigger epoll() 2) Under UDP flood, we can loop forever without yielding to other processes, potentially hanging the host, especially on non SMP. This patch is an attempt to make things better. We might in the future add extra support for rt applications wanting to better control time spent doing a recv() in a hostile environment. For example we could validate checksums before queuing packets in socket receive queue. Signed-off-by: Eric Dumazet Cc: Willem de Bruijn Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings CVE-2015-5364 CVE-2015-5366 Signed-off-by: Willy Tarreau

ipv6: call udp_push_pending_frames when uncorking a socket with AF_INET pending data

2014-05-19T05:54:30Z

CVE-2013-4162 BugLink: http://bugs.launchpad.net/bugs/1205070 We accidentally call down to ip6_push_pending_frames when uncorking pending AF_INET data on a ipv6 socket. This results in the following splat (from Dave Jones): skbuff: skb_under_panic: text:ffffffff816765f6 len:48 put:40 head:ffff88013deb6df0 data:ffff88013deb6dec tail:0x2c end:0xc0 dev: ------------[ cut here ]------------ kernel BUG at net/core/skbuff.c:126! invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC Modules linked in: dccp_ipv4 dccp 8021q garp bridge stp dlci mpoa snd_seq_dummy sctp fuse hidp tun bnep nfnetlink scsi_transport_iscsi rfcomm can_raw can_bcm af_802154 appletalk caif_socket can caif ipt_ULOG x25 rose af_key pppoe pppox ipx phonet irda llc2 ppp_generic slhc p8023 psnap p8022 llc crc_ccitt atm bluetooth +netrom ax25 nfc rfkill rds af_rxrpc coretemp hwmon kvm_intel kvm crc32c_intel snd_hda_codec_realtek ghash_clmulni_intel microcode pcspkr snd_hda_codec_hdmi snd_hda_intel snd_hda_codec snd_hwdep usb_debug snd_seq snd_seq_device snd_pcm e1000e snd_page_alloc snd_timer ptp snd pps_core soundcore xfs libcrc32c CPU: 2 PID: 8095 Comm: trinity-child2 Not tainted 3.10.0-rc7+ #37 task: ffff8801f52c2520 ti: ffff8801e6430000 task.ti: ffff8801e6430000 RIP: 0010:[] [] skb_panic+0x63/0x65 RSP: 0018:ffff8801e6431de8 EFLAGS: 00010282 RAX: 0000000000000086 RBX: ffff8802353d3cc0 RCX: 0000000000000006 RDX: 0000000000003b90 RSI: ffff8801f52c2ca0 RDI: ffff8801f52c2520 RBP: ffff8801e6431e08 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: ffff88022ea0c800 R13: ffff88022ea0cdf8 R14: ffff8802353ecb40 R15: ffffffff81cc7800 FS: 00007f5720a10740(0000) GS:ffff880244c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000005862000 CR3: 000000022843c000 CR4: 00000000001407e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Stack: ffff88013deb6dec 000000000000002c 00000000000000c0 ffffffff81a3f6e4 ffff8801e6431e18 ffffffff8159a9aa ffff8801e6431e90 ffffffff816765f6 ffffffff810b756b 0000000700000002 ffff8801e6431e40 0000fea9292aa8c0 Call Trace: [] skb_push+0x3a/0x40 [] ip6_push_pending_frames+0x1f6/0x4d0 [] ? mark_held_locks+0xbb/0x140 [] udp_v6_push_pending_frames+0x2b9/0x3d0 [] ? udplite_getfrag+0x20/0x20 [] udp_lib_setsockopt+0x1aa/0x1f0 [] ? fget_light+0x387/0x4f0 [] udpv6_setsockopt+0x34/0x40 [] sock_common_setsockopt+0x14/0x20 [] SyS_setsockopt+0x71/0xd0 [] tracesys+0xdd/0xe2 Code: 00 00 48 89 44 24 10 8b 87 d8 00 00 00 48 89 44 24 08 48 8b 87 e8 00 00 00 48 c7 c7 c0 04 aa 81 48 89 04 24 31 c0 e8 e1 7e ff ff <0f> 0b 55 48 89 e5 0f 0b 55 48 89 e5 0f 0b 55 48 89 e5 0f 0b 55 RIP [] skb_panic+0x63/0x65 RSP This patch adds a check if the pending data is of address family AF_INET and directly calls udp_push_ending_frames from udp_v6_push_pending_frames if that is the case. This bug was found by Dave Jones with trinity. (Also move the initialization of fl6 below the AF_INET check, even if not strictly necessary.) Cc: Dave Jones Cc: YOSHIFUJI Hideaki Signed-off-by: Hannes Frederic Sowa Signed-off-by: David S. Miller (back ported from commit 8822b64a0fa64a5dd1dfcf837c5b0be83f8c05d1) Signed-off-by: Luis Henriques Acked-by: Brad Figg Signed-off-by: Tim Gardner Signed-off-by: Willy Tarreau

inet: fix possible seqlock deadlocks

2014-05-19T05:54:05Z

[ Upstream commit f1d8cba61c3c4b1eb88e507249c4cb8d635d9a76 ] In commit c9e9042994d3 ("ipv4: fix possible seqlock deadlock") I left another places where IP_INC_STATS_BH() were improperly used. udp_sendmsg(), ping_v4_sendmsg() and tcp_v4_connect() are called from process context, not from softirq context. This was detected by lockdep seqlock support. Reported-by: jongman heo Fixes: 584bdf8cbdf6 ("[IPV4]: Fix "ipOutNoRoutes" counter error for TCP and UDP") Fixes: c319b4d76b9e ("net: ipv4: add IPPROTO_ICMP socket kind") Signed-off-by: Eric Dumazet Cc: Hannes Frederic Sowa Acked-by: Hannes Frederic Sowa Signed-off-by: David S. Miller Signed-off-by: Willy Tarreau

inet: fix addr_len/msg->msg_namelen assignment in recv_error and rxpmtu functions

2014-05-19T05:54:01Z

[ Upstream commit 85fbaa75037d0b6b786ff18658ddf0b4014ce2a4 ] Commit bceaa90240b6019ed73b49965eac7d167610be69 ("inet: prevent leakage of uninitialized memory to user in recv syscalls") conditionally updated addr_len if the msg_name is written to. The recv_error and rxpmtu functions relied on the recvmsg functions to set up addr_len before. As this does not happen any more we have to pass addr_len to those functions as well and set it to the size of the corresponding sockaddr length. This broke traceroute and such. Fixes: bceaa90240b6 ("inet: prevent leakage of uninitialized memory to user in recv syscalls") Reported-by: Brad Spengler Reported-by: Tom Labanowski Cc: mpb Cc: David S. Miller Cc: Eric Dumazet Signed-off-by: Hannes Frederic Sowa Signed-off-by: David S. Miller Signed-off-by: Willy Tarreau

inet: prevent leakage of uninitialized memory to user in recv syscalls

2014-05-19T05:53:59Z

[ Upstream commit bceaa90240b6019ed73b49965eac7d167610be69 ] Only update *addr_len when we actually fill in sockaddr, otherwise we can return uninitialized memory from the stack to the caller in the recvfrom, recvmmsg and recvmsg syscalls. Drop the the (addr_len == NULL) checks because we only get called with a valid addr_len pointer either from sock_common_recvmsg or inet_recvmsg. If a blocking read waits on a socket which is concurrently shut down we now return zero and set msg_msgnamelen to 0. Reported-by: mpb Suggested-by: Eric Dumazet Signed-off-by: Hannes Frederic Sowa Signed-off-by: David S. Miller [wt: no ieee802154, ping nor l2tp in 2.6.32] Signed-off-by: Willy Tarreau

inet: add RCU protection to inet->opt

2013-06-10T09:43:31Z

commit f6d8bd051c391c1c0458a30b2a7abcd939329259 upstream. We lack proper synchronization to manipulate inet->opt ip_options Problem is ip_make_skb() calls ip_setup_cork() and ip_setup_cork() possibly makes a copy of ipc->opt (struct ip_options), without any protection against another thread manipulating inet->opt. Another thread can change inet->opt pointer and free old one under us. Use RCU to protect inet->opt (changed to inet->inet_opt). Instead of handling atomic refcounts, just copy ip_options when necessary, to avoid cache line dirtying. We cant insert an rcu_head in struct ip_options since its included in skb->cb[], so this patch is large because I had to introduce a new ip_options_rcu structure. Signed-off-by: Eric Dumazet Cc: Herbert Xu Signed-off-by: David S. Miller [dannf/bwh: backported to Debian's 2.6.32] Signed-off-by: Ben Hutchings Signed-off-by: Willy Tarreau

net: sock_queue_err_skb() dont mess with sk_forward_alloc

2012-02-13T19:28:51Z

commit b1faf5666438090a4dc4fceac8502edc7788b7e3 upstream. Correct sk_forward_alloc handling for error_queue would need to use a backlog of frames that softirq handler could not deliver because socket is owned by user thread. Or extend backlog processing to be able to process normal and error packets. Another possibility is to not use mem charge for error queue, this is what I implemented in this patch. Note: this reverts commit 29030374 (net: fix sk_forward_alloc corruptions), since we dont need to lock socket anymore. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Cc: 单卫 Signed-off-by: Greg Kroah-Hartman