| Message ID | 1397214001-30273-1-git-send-email-luis.henriques@canonical.com |
|---|---|
| State | New |
| Headers | show |
diff --git a/lib/nlattr.c b/lib/nlattr.c index 18eca78..fc67547 100644 --- a/lib/nlattr.c +++ b/lib/nlattr.c @@ -303,9 +303,15 @@ int nla_memcmp(const struct nlattr *nla, const void *data, */ int nla_strcmp(const struct nlattr *nla, const char *str) { - int len = strlen(str) + 1; - int d = nla_len(nla) - len; + int len = strlen(str); + char *buf = nla_data(nla); + int attrlen = nla_len(nla); + int d; + if (attrlen > 0 && buf[attrlen - 1] == '\0') + attrlen--; + + d = attrlen - len; if (d == 0) d = memcmp(nla_data(nla), str, len);
This is a note to let you know that I have just added a patch titled netlink: don't compare the nul-termination in nla_strcmp to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.11.y-queue If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.11.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Luis ------ From 665ef760250e98274b6aa376f3c727fe2d401bcb Mon Sep 17 00:00:00 2001 From: Pablo Neira <pablo@netfilter.org> Date: Tue, 1 Apr 2014 19:38:44 +0200 Subject: netlink: don't compare the nul-termination in nla_strcmp commit 8b7b932434f5eee495b91a2804f5b64ebb2bc835 upstream. nla_strcmp compares the string length plus one, so it's implicitly including the nul-termination in the comparison. int nla_strcmp(const struct nlattr *nla, const char *str) { int len = strlen(str) + 1; ... d = memcmp(nla_data(nla), str, len); However, if NLA_STRING is used, userspace can send us a string without the nul-termination. This is a problem since the string comparison will not match as the last byte may be not the nul-termination. Fix this by skipping the comparison of the nul-termination if the attribute data is nul-terminated. Suggested by Thomas Graf. Cc: Florian Westphal <fw@strlen.de> Cc: Thomas Graf <tgraf@suug.ch> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- lib/nlattr.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) -- 1.9.1