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-rw-r--r--main/quagga/0003-bgpd-fix-double-free-after-extcommunity-set-BZ-799.patch58
1 files changed, 58 insertions, 0 deletions
diff --git a/main/quagga/0003-bgpd-fix-double-free-after-extcommunity-set-BZ-799.patch b/main/quagga/0003-bgpd-fix-double-free-after-extcommunity-set-BZ-799.patch
new file mode 100644
index 000000000..fbd226822
--- /dev/null
+++ b/main/quagga/0003-bgpd-fix-double-free-after-extcommunity-set-BZ-799.patch
@@ -0,0 +1,58 @@
+From 27bf90a14670283a899b96c56dd23f8413e0973e Mon Sep 17 00:00:00 2001
+From: David Lamparter <equinox@opensourcerouting.org>
+Date: Wed, 4 Jun 2014 00:59:01 +0200
+Subject: [PATCH] bgpd: fix double free after extcommunity set (BZ#799)
+
+The route-map extcommunity set code was incorrectly assuming that it
+owns the intern'd struct ecommunity reference. In reality, the intern'd
+reference belongs to bgp_update_receive() and we're not supposed to
+touch it in the route-map code.
+
+Instead, like all the other set commands, we use a on-heap but
+non-intern'd ecommunity to set the new value. This is then either
+intern'd in bgp_update_main/_rsclient() through bgp_attr_intern(), or
+free'd through bgp_attr_flush().
+
+This fixes Bugzilla #799, which is that bgpd otherwise crashes with a
+double free. The ecommunity got unintern'd first in the route-map set
+command, then in bgp_update_receive().
+
+Debugged-by: Milan Kocian <milon@wq.cz>
+Reported-by: Florian S <florian@herrenlohe.de>
+Signed-off-by: David Lamparter <equinox@opensourcerouting.org>
+---
+ bgpd/bgp_routemap.c | 15 ++++++++++-----
+ 1 file changed, 10 insertions(+), 5 deletions(-)
+
+diff --git a/bgpd/bgp_routemap.c b/bgpd/bgp_routemap.c
+index eb5e80f..36d177d 100644
+--- a/bgpd/bgp_routemap.c
++++ b/bgpd/bgp_routemap.c
+@@ -1552,14 +1552,19 @@ route_set_ecommunity (void *rule, struct prefix *prefix,
+ old_ecom = (bgp_attr_extra_get (bgp_info->attr))->ecommunity;
+
+ if (old_ecom)
+- new_ecom = ecommunity_merge (ecommunity_dup (old_ecom), ecom);
++ {
++ new_ecom = ecommunity_merge (ecommunity_dup (old_ecom), ecom);
++
++ /* old_ecom->refcnt = 1 => owned elsewhere, e.g. bgp_update_receive()
++ * ->refcnt = 0 => set by a previous route-map statement */
++ if (!old_ecom->refcnt)
++ ecommunity_free (&old_ecom);
++ }
+ else
+ new_ecom = ecommunity_dup (ecom);
+
+- bgp_info->attr->extra->ecommunity = ecommunity_intern (new_ecom);
+-
+- if (old_ecom)
+- ecommunity_unintern (&old_ecom);
++ /* will be intern()'d or attr_flush()'d by bgp_update_main() */
++ bgp_info->attr->extra->ecommunity = new_ecom;
+
+ bgp_info->attr->flag |= ATTR_FLAG_BIT (BGP_ATTR_EXT_COMMUNITIES);
+ }
+--
+2.0.1
+