Fix for inabiltiy to send zero sized UDP packets (rhbz 1365940)

This commit is contained in:
Laura Abbott 2016-08-23 16:52:53 -07:00
parent 0c1a1f4ca9
commit 8fd61b3a44
2 changed files with 79 additions and 0 deletions

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@ -0,0 +1,73 @@
From 9f30f83eb6347afa6b1d1df1065608c2b4485e2b Mon Sep 17 00:00:00 2001
From: Eric Dumazet <edumazet@google.com>
Date: Tue, 23 Aug 2016 13:59:33 -0700
Subject: [PATCH] udp: fix poll() issue with zero sized packets
Laura tracked poll() [and friends] regression caused by commit
e6afc8ace6dd ("udp: remove headers from UDP packets before queueing")
udp_poll() needs to know if there is a valid packet in receive queue,
even if its payload length is 0.
Change first_packet_length() to return an signed int, and use -1
as the indication of an empty queue.
Fixes: e6afc8ace6dd ("udp: remove headers from UDP packets before queueing")
Reported-by: Laura Abbott <labbott@redhat.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Tested-by: Laura Abbott <labbott@redhat.com>
---
net/ipv4/udp.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index e61f7cd..00d18c5 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -1182,13 +1182,13 @@ out:
* @sk: socket
*
* Drops all bad checksum frames, until a valid one is found.
- * Returns the length of found skb, or 0 if none is found.
+ * Returns the length of found skb, or -1 if none is found.
*/
-static unsigned int first_packet_length(struct sock *sk)
+static int first_packet_length(struct sock *sk)
{
struct sk_buff_head list_kill, *rcvq = &sk->sk_receive_queue;
struct sk_buff *skb;
- unsigned int res;
+ int res;
__skb_queue_head_init(&list_kill);
@@ -1203,7 +1203,7 @@ static unsigned int first_packet_length(struct sock *sk)
__skb_unlink(skb, rcvq);
__skb_queue_tail(&list_kill, skb);
}
- res = skb ? skb->len : 0;
+ res = skb ? skb->len : -1;
spin_unlock_bh(&rcvq->lock);
if (!skb_queue_empty(&list_kill)) {
@@ -1232,7 +1232,7 @@ int udp_ioctl(struct sock *sk, int cmd, unsigned long arg)
case SIOCINQ:
{
- unsigned int amount = first_packet_length(sk);
+ int amount = max_t(int, 0, first_packet_length(sk));
return put_user(amount, (int __user *)arg);
}
@@ -2184,7 +2184,7 @@ unsigned int udp_poll(struct file *file, struct socket *sock, poll_table *wait)
/* Check for false positives due to checksum errors */
if ((mask & POLLRDNORM) && !(file->f_flags & O_NONBLOCK) &&
- !(sk->sk_shutdown & RCV_SHUTDOWN) && !first_packet_length(sk))
+ !(sk->sk_shutdown & RCV_SHUTDOWN) && first_packet_length(sk) == -1)
mask &= ~(POLLIN | POLLRDNORM);
return mask;
--
2.7.4

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@ -612,6 +612,9 @@ Patch842: qxl-reapply-cursor-after-SetCrtc-calls.patch
#CVE-2016-6828 rhbz 1367091,1367092 #CVE-2016-6828 rhbz 1367091,1367092
Patch843: tcp-fix-use-after-free-in-tcp_xmit_retransmit_queue.patch Patch843: tcp-fix-use-after-free-in-tcp_xmit_retransmit_queue.patch
#rhbz 1365940
Patch844: 0001-udp-fix-poll-issue-with-zero-sized-packets.patch
# END OF PATCH DEFINITIONS # END OF PATCH DEFINITIONS
%endif %endif
@ -2146,6 +2149,9 @@ fi
# #
# #
%changelog %changelog
* Tue Aug 23 2016 Laura Abbott <labbott@fedoraproject.org>
- Fix for inabiltiy to send zero sized UDP packets (rhbz 1365940)
* Tue Aug 23 2016 Peter Robinson <pbrobinson@fedoraproject.org> * Tue Aug 23 2016 Peter Robinson <pbrobinson@fedoraproject.org>
- Qualcomm QDF2432 errata fix - Qualcomm QDF2432 errata fix
- Move to upstream patches for ACPI SPCR (serial console) - Move to upstream patches for ACPI SPCR (serial console)