[PATCH 3.12 07/39] route: Use ipv4_mtu instead of raw rt_pmtu

From	Jiri Slaby <jslaby@suse.cz>
Newsgroups	linux.kernel
Subject	[PATCH 3.12 07/39] route: Use ipv4_mtu instead of raw rt_pmtu
Date	2016-01-25 13:10 +0100
Message-ID	<qUO81-3Gp-11@gated-at.bofh.it> (permalink)
References	<qUNYl-3kJ-3@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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From: Herbert Xu <herbert@gondor.apana.org.au>

3.12-stable review patch.  If anyone has any objections, please let me know.

===============

commit cb6ccf09d6b94bec4def1ac5cf4678d12b216474 upstream.

The commit 3cdaa5be9e81a914e633a6be7b7d2ef75b528562 ("ipv4: Don't
increase PMTU with Datagram Too Big message") broke PMTU in cases
where the rt_pmtu value has expired but is smaller than the new
PMTU value.

This obsolete rt_pmtu then prevents the new PMTU value from being
installed.

Fixes: 3cdaa5be9e81 ("ipv4: Don't increase PMTU with Datagram Too Big message")
Reported-by: Gerd v. Egidy <gerd.von.egidy@intra2net.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
 net/ipv4/route.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index fe0c761a8fce..54874e4767de 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -985,10 +985,7 @@ static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu)
 	if (dst_metric_locked(dst, RTAX_MTU))
 		return;
 
-	if (dst->dev->mtu < mtu)
-		return;
-
-	if (rt->rt_pmtu && rt->rt_pmtu < mtu)
+	if (ipv4_mtu(dst) < mtu)
 		return;
 
 	if (mtu < ip_rt_min_pmtu)
-- 
2.7.0

Thread

[PATCH 3.12 01/39] efi: Disable interrupts around EFI calls, not in the epilog/prolog calls Jiri Slaby <jslaby@suse.cz> - 2016-01-25 13:00 +0100
  [PATCH 3.12 02/39] tools: Add a "make all" rule Jiri Slaby <jslaby@suse.cz> - 2016-01-25 13:00 +0100
  [PATCH 3.12 26/39] udp: properly support MSG_PEEK with truncated buffers Jiri Slaby <jslaby@suse.cz> - 2016-01-25 13:00 +0100
  [PATCH 3.12 24/39] KEYS: Fix race between read and revoke Jiri Slaby <jslaby@suse.cz> - 2016-01-25 13:00 +0100
  [PATCH 3.12 22/39] sctp: Prevent soft lockup when sctp_accept() is called during a timeout event Jiri Slaby <jslaby@suse.cz> - 2016-01-25 13:00 +0100
  [PATCH 3.12 28/39] xen/gntdev: Grant maps should not be subject to NUMA balancing Jiri Slaby <jslaby@suse.cz> - 2016-01-25 13:00 +0100
  [PATCH 3.12 36/39] MAINTAINERS: Add public mailing list for ARC Jiri Slaby <jslaby@suse.cz> - 2016-01-25 13:00 +0100
  [PATCH 3.12 27/39] x86/signal: Fix restart_syscall number for x32 tasks Jiri Slaby <jslaby@suse.cz> - 2016-01-25 13:00 +0100
  [PATCH 3.12 16/39] staging/dgnc: fix info leak in ioctl Jiri Slaby <jslaby@suse.cz> - 2016-01-25 13:00 +0100
  [PATCH 3.12 37/39] ARC: Fix silly typo in MAINTAINERS file commit 30b9dbee895ff0d5cbf155bd1ef3f0f5992bca6f upstream. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Jiri Slaby <jslaby@suse.cz> - 2016-01-25 13:00 +0100
  [PATCH 3.12 25/39] KEYS: Fix keyring ref leak in join_session_keyring() Jiri Slaby <jslaby@suse.cz> - 2016-01-25 13:00 +0100
  [PATCH 3.12 32/39] x86/boot: Double BOOT_HEAP_SIZE to 64KB Jiri Slaby <jslaby@suse.cz> - 2016-01-25 13:00 +0100
  [PATCH 3.12 38/39] isdn_ppp: Add checks for allocation failure in isdn_ppp_open() Jiri Slaby <jslaby@suse.cz> - 2016-01-25 13:00 +0100
  [PATCH 3.12 12/39] block: Always check queue limits for cloned requests Jiri Slaby <jslaby@suse.cz> - 2016-01-25 13:00 +0100
  [PATCH 3.12 20/39] m68k/mm: Check for mm != NULL in do_page_fault() debug code Jiri Slaby <jslaby@suse.cz> - 2016-01-25 13:00 +0100
  [PATCH 3.12 18/39] m32r: fix potential NULL-pointer dereference Jiri Slaby <jslaby@suse.cz> - 2016-01-25 13:00 +0100
  [PATCH 3.12 15/39] module: remove MODULE_GENERIC_TABLE Jiri Slaby <jslaby@suse.cz> - 2016-01-25 13:00 +0100
  [PATCH 3.12 23/39] USB: quirks: Fix another ELAN touchscreen Jiri Slaby <jslaby@suse.cz> - 2016-01-25 13:00 +0100
  [PATCH 3.12 17/39] pm: use GFP_ATOMIC when pm core call this function Jiri Slaby <jslaby@suse.cz> - 2016-01-25 13:00 +0100
  [PATCH 3.12 39/39] ppp, slip: Validate VJ compression slot parameters completely Jiri Slaby <jslaby@suse.cz> - 2016-01-25 13:00 +0100
  [PATCH 3.12 30/39] KVM: PPC: Book3S HV: Prohibit setting illegal transaction state in MSR Jiri Slaby <jslaby@suse.cz> - 2016-01-25 13:00 +0100
  [PATCH 3.12 21/39] m68k/mac: Make SCC reset work more reliably Jiri Slaby <jslaby@suse.cz> - 2016-01-25 13:00 +0100
  [PATCH 3.12 34/39] ALSA: hda - Add Intel Lewisburg device IDs Audio Jiri Slaby <jslaby@suse.cz> - 2016-01-25 13:00 +0100
  [PATCH 3.12 04/39] dlm: make posix locks interruptible Jiri Slaby <jslaby@suse.cz> - 2016-01-25 13:00 +0100
  [PATCH 3.12 35/39] ALSA: hda - Apply pin fixup for HP ProBook 6550b Jiri Slaby <jslaby@suse.cz> - 2016-01-25 13:00 +0100
  [PATCH 3.12 14/39] qla2xxx: Fix hardware lock/unlock issue causing kernel panic. Jiri Slaby <jslaby@suse.cz> - 2016-01-25 13:00 +0100
  [PATCH 3.12 29/39] x86/xen: don't reset vcpu_info on a cancelled suspend Jiri Slaby <jslaby@suse.cz> - 2016-01-25 13:00 +0100
  [PATCH 3.12 10/39] drm/i915: Fix SRC_COPY width on 830/845g Jiri Slaby <jslaby@suse.cz> - 2016-01-25 13:10 +0100
  [PATCH 3.12 07/39] route: Use ipv4_mtu instead of raw rt_pmtu Jiri Slaby <jslaby@suse.cz> - 2016-01-25 13:10 +0100
  [PATCH 3.12 13/39] Input: aiptek - fix crash on detecting device without endpoints Jiri Slaby <jslaby@suse.cz> - 2016-01-25 13:10 +0100
  [PATCH 3.12 05/39] PCI: Drop "setting latency timer" messages Jiri Slaby <jslaby@suse.cz> - 2016-01-25 13:10 +0100
  [PATCH 3.12 11/39] lpfc: Fix null ndlp dereference in target_reset_handler Jiri Slaby <jslaby@suse.cz> - 2016-01-25 13:10 +0100
  [PATCH 3.12 09/39] ring-buffer: Always run per-cpu ring buffer resize with schedule_work_on() Jiri Slaby <jslaby@suse.cz> - 2016-01-25 13:10 +0100
  [PATCH 3.12 06/39] ipv4: Don't increase PMTU with Datagram Too Big message. Jiri Slaby <jslaby@suse.cz> - 2016-01-25 13:10 +0100
  [PATCH 3.12 03/39] ALSA: hda - Fix noise problems on Thinkpad T440s Jiri Slaby <jslaby@suse.cz> - 2016-01-25 13:10 +0100
  [PATCH 3.12 08/39] SUNRPC: Fix oops when trace sunrpc_task events in nfs client Jiri Slaby <jslaby@suse.cz> - 2016-01-25 13:10 +0100

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