From: Willy Tarreau <w@1wt.eu>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Eric Dumazet <edumazet@google.com>,
Herbert Xu <herbert@gondor.apana.org.au>,
"David S. Miller" <davem@davemloft.net>,
Ben Hutchings <ben@decadent.org.uk>, Willy Tarreau <w@1wt.eu>
Subject: [PATCH 2.6.32 08/42] udp: properly support MSG_PEEK with truncated buffers
Date: Sat, 23 Jan 2016 15:12:29 +0100 [thread overview]
Message-ID: <20160123141222.324179193@1wt.eu> (raw)
In-Reply-To: <aa387f55227cb730b41e3d621bf460ff@local>
2.6.32-longterm review patch. If anyone has any objections, please let me know.
------------------
From: Eric Dumazet <edumazet@google.com>
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 <edumazet@google.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
(cherry picked from commit 18a6eba2eabbcb50a78210b16f7dd43d888a537b)
Signed-off-by: Willy Tarreau <w@1wt.eu>
---
net/ipv4/udp.c | 6 ++++--
net/ipv6/udp.c | 6 ++++--
2 files changed, 8 insertions(+), 4 deletions(-)
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 3ae286b..f12e404 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -941,6 +941,7 @@ int udp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
int peeked;
int err;
int is_udplite = IS_UDPLITE(sk);
+ bool checksum_valid = false;
if (flags & MSG_ERRQUEUE)
return ip_recv_error(sk, msg, len, addr_len);
@@ -965,11 +966,12 @@ try_again:
*/
if (copied < ulen || UDP_SKB_CB(skb)->partial_cov) {
- if (udp_lib_checksum_complete(skb))
+ checksum_valid = !udp_lib_checksum_complete(skb);
+ if (!checksum_valid)
goto csum_copy_err;
}
- if (skb_csum_unnecessary(skb))
+ if (checksum_valid || skb_csum_unnecessary(skb))
err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr),
msg->msg_iov, copied);
else {
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index 0b023f3..3f8b3b6 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -198,6 +198,7 @@ int udpv6_recvmsg(struct kiocb *iocb, struct sock *sk,
int peeked;
int err;
int is_udplite = IS_UDPLITE(sk);
+ bool checksum_valid = false;
int is_udp4;
if (flags & MSG_ERRQUEUE)
@@ -225,11 +226,12 @@ try_again:
*/
if (copied < ulen || UDP_SKB_CB(skb)->partial_cov) {
- if (udp_lib_checksum_complete(skb))
+ checksum_valid = !udp_lib_checksum_complete(skb);
+ if (!checksum_valid)
goto csum_copy_err;
}
- if (skb_csum_unnecessary(skb))
+ if (checksum_valid || skb_csum_unnecessary(skb))
err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr),
msg->msg_iov, copied );
else {
--
1.7.12.2.21.g234cd45.dirty
next prev parent reply other threads:[~2016-01-23 14:12 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <aa387f55227cb730b41e3d621bf460ff@local>
2016-01-23 14:12 ` [PATCH 2.6.32 01/42] ip6mr: call del_timer_sync() in ip6mr_free_table() Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 02/42] isdn_ppp: Add checks for allocation failure in isdn_ppp_open() Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 04/42] RDS: fix race condition when sending a message on unbound socket Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 05/42] unix: avoid use-after-free in ep_remove_wait_queue Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 06/42] ext4: Fix null dereference in ext4_fill_super() Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 07/42] Revert "net: add length argument to skb_copy_and_csum_datagram_iovec" Willy Tarreau
2016-01-23 14:12 ` Willy Tarreau [this message]
2016-01-23 14:12 ` [PATCH 2.6.32 09/42] KEYS: Fix race between read and revoke Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 11/42] net: fix warnings in make htmldocs by moving macro definition out of field declaration Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 12/42] bluetooth: Validate socket address length in sco_sock_bind() Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 13/42] sctp: translate host order to network order when setting a hmacid Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 14/42] fuse: break infinite loop in fuse_fill_write_pages() Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 15/42] fix sysvfs symlinks Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 16/42] vfs: Avoid softlockups with sendfile(2) Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 17/42] ext4: Fix handling of extended tv_sec Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 18/42] nfs: if we have no valid attrs, then dont declare the attribute cache valid Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 19/42] wan/x25: Fix use-after-free in x25_asy_open_tty() Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 20/42] ipv4: igmp: Allow removing groups from a removed interface Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 21/42] sched/core: Remove false-positive warning from wake_up_process() Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 22/42] ipmi: move timer init to before irq is setup Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 23/42] tcp: initialize tp->copied_seq in case of cross SYN connection Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 24/42] net, scm: fix PaX detected msg_controllen overflow in scm_detach_fds Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 25/42] sctp: update the netstamp_needed counter when copying sockets Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 26/42] af_unix: fix a fatal race with bit fields Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 27/42] rfkill: copy the name into the rfkill struct Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 28/42] ses: Fix problems with simple enclosures Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 29/42] ses: fix additional element traversal bug Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 30/42] tty: Fix GPF in flush_to_ldisc() Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 31/42] mISDN: fix a loop count Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 32/42] ser_gigaset: fix deallocation of platform device structure Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 33/42] spi: fix parent-device reference leak Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 34/42] s390/dis: Fix handling of format specifiers Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 35/42] USB: ipaq.c: fix a timeout loop Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 36/42] USB: fix invalid memory access in hub_activate() Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 37/42] MIPS: Fix restart of indirect syscalls Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 38/42] parisc: Fix syscall restarts Willy Tarreau
2016-01-23 14:13 ` [PATCH 2.6.32 39/42] ipv6/addrlabel: fix ip6addrlbl_get() Willy Tarreau
2016-01-23 14:13 ` [PATCH 2.6.32 40/42] mm/memory_hotplug.c: check for missing sections in test_pages_in_a_zone() Willy Tarreau
2016-01-23 18:13 ` Ben Hutchings
2016-01-23 18:29 ` Willy Tarreau
2016-01-23 19:05 ` Willy Tarreau
2016-01-23 14:13 ` [PATCH 2.6.32 41/42] KVM: x86: Reload pit counters for all channels when restoring state Willy Tarreau
2016-01-23 14:13 ` [PATCH 2.6.32 42/42] kvm: x86: only channel 0 of the i8254 is linked to the HPET Willy Tarreau
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