[SRU][Wily][PATCH] UBUNTU: SAUCE: (noup) netfilter: x_tables: check for size overflow
Chris J Arges
chris.j.arges at canonical.com
Thu Mar 10 18:58:37 UTC 2016
From: Florian Westphal <fw at strlen.de>
BugLink: http://bugs.launchpad.net/bugs/1555353
http://marc.info/?l=netfilter-devel&m=145757136822750&w=2
Ben Hawkes says:
integer overflow in xt_alloc_table_info, which on 32-bit systems can
lead to small structure allocation and a copy_from_user based heap
corruption.
Reported-by: Ben Hawkes <hawkes at google.com>
Signed-off-by: Florian Westphal <fw at strlen.de>
Signed-off-by: Tim Gardner <tim.gardner at canonical.com>
Signed-off-by: Chris J Arges <chris.j.arges at canonical.com>
---
net/netfilter/x_tables.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c
index d324fe7..7884241 100644
--- a/net/netfilter/x_tables.c
+++ b/net/netfilter/x_tables.c
@@ -661,6 +661,9 @@ struct xt_table_info *xt_alloc_table_info(unsigned int size)
struct xt_table_info *info = NULL;
size_t sz = sizeof(*info) + size;
+ if (sz < size || sz < sizeof(*info))
+ return NULL;
+
/* Pedantry: prevent them from hitting BUG() in vmalloc.c --RR */
if ((SMP_ALIGN(size) >> PAGE_SHIFT) + 2 > totalram_pages)
return NULL;
--
2.7.0
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