From: Phil Sutter <phil@nwl.cc>
To: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: netfilter-devel@vger.kernel.org
Subject: [libnftnl PATCH 5/7] common: Avoid integer overflow in nftnl_batch_is_supported()
Date: Fri, 12 Aug 2016 01:33:37 +0200 [thread overview]
Message-ID: <1470958419-32602-6-git-send-email-phil@nwl.cc> (raw)
In-Reply-To: <1470958419-32602-1-git-send-email-phil@nwl.cc>
time() may return -1 which is then assigned to an unsigned integer type
and used as sequence number. The following code increments that number
multiple times, so it may overflow and get libmnl confused. To avoid
this, fall back to a starting sequence number of zero in case the call
to time() failed.
Signed-off-by: Phil Sutter <phil@nwl.cc>
---
src/common.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/src/common.c b/src/common.c
index bf4176ceb76eb..2189cc8a3e882 100644
--- a/src/common.c
+++ b/src/common.c
@@ -192,6 +192,9 @@ int nftnl_batch_is_supported(void)
uint32_t seq = time(NULL), req_seq;
int ret;
+ if (seq == (uint32_t)-1)
+ seq = 0;
+
nl = mnl_socket_open(NETLINK_NETFILTER);
if (nl == NULL)
return -1;
--
2.8.2
next prev parent reply other threads:[~2016-08-11 23:34 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-08-11 23:33 [libnftnl PATCH 0/7] A bunch of covscan detected fixes Phil Sutter
2016-08-11 23:33 ` [libnftnl PATCH 1/7] set: prevent memleak in nftnl_jansson_parse_set_info() Phil Sutter
2016-08-11 23:33 ` [libnftnl PATCH 2/7] ruleset: Prevent memleak in nftnl_ruleset_snprintf_*() functions Phil Sutter
2016-08-11 23:42 ` Pablo Neira Ayuso
2016-08-12 0:44 ` Phil Sutter
2016-08-12 8:38 ` Pablo Neira Ayuso
2016-08-11 23:33 ` [libnftnl PATCH 3/7] expr/ct: prevent array index overrun in ctkey2str() Phil Sutter
2016-08-11 23:33 ` [libnftnl PATCH 4/7] expr/limit: Drop unreachable code in limit_to_type() Phil Sutter
2016-08-11 23:33 ` Phil Sutter [this message]
2016-08-11 23:48 ` [libnftnl PATCH 5/7] common: Avoid integer overflow in nftnl_batch_is_supported() Pablo Neira Ayuso
2016-08-11 23:33 ` [libnftnl PATCH 6/7] Avoid returning uninitialized data Phil Sutter
2016-08-11 23:33 ` [libnftnl PATCH 7/7] ruleset: Initialize ctx.flags before calling nftnl_ruleset_ctx_set() Phil Sutter
2016-08-11 23:58 ` [libnftnl PATCH 0/7] A bunch of covscan detected fixes Pablo Neira Ayuso
2016-08-12 0:05 ` Pablo Neira Ayuso
2016-08-12 0:47 ` Phil Sutter
2016-08-12 8:40 ` Pablo Neira Ayuso
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