[PATCH nf-next] netfilter: xt_osf: Use explicit member assignment to avoid implicit no padding rule
flat view
STALE3670d
From: <hidden>
Date: 2016-09-27 04:39:53
Also in:
netfilter-devel
Subsystem:
netfilter, networking [general], the rest · Maintainers:
Pablo Neira Ayuso, Florian Westphal, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
From: Gao Feng <redacted> Current xt_osf codes use memcmp to check if two user fingers are same, so it depends on that the struct xt_osf_user_finger is no padding. It is one implicit rule, and is not good to maintain. Now use zero memory and assign the members explicitly. Signed-off-by: Gao Feng <redacted> --- net/netfilter/xt_osf.c | 32 ++++++++++++++++++++++++++++++-- 1 file changed, 30 insertions(+), 2 deletions(-)
diff --git a/net/netfilter/xt_osf.c b/net/netfilter/xt_osf.c
index 2455b69..9793670 100644
--- a/net/netfilter/xt_osf.c
+++ b/net/netfilter/xt_osf.c@@ -61,6 +61,34 @@ static const struct nla_policy xt_osf_policy[OSF_ATTR_MAX + 1] = { [OSF_ATTR_FINGER] = { .len = sizeof(struct xt_osf_user_finger) }, }; +static void copy_user_finger(struct xt_osf_user_finger *dst, + const struct xt_osf_user_finger *src) +{ +#define OSF_COPY_MEMBER(mem) dst->mem = src->mem + + int i; + + OSF_COPY_MEMBER(wss.wc); + OSF_COPY_MEMBER(wss.val); + + OSF_COPY_MEMBER(ttl); + OSF_COPY_MEMBER(df); + OSF_COPY_MEMBER(ss); + OSF_COPY_MEMBER(mss); + OSF_COPY_MEMBER(opt_num); + + memcpy(dst->genre, src->genre, sizeof(dst->genre)); + memcpy(dst->version, src->version, sizeof(dst->version)); + memcpy(dst->subtype, src->subtype, sizeof(dst->subtype)); + + for (i = 0; i < MAX_IPOPTLEN; ++i) { + OSF_COPY_MEMBER(opt[i].kind); + OSF_COPY_MEMBER(opt[i].length); + OSF_COPY_MEMBER(opt[i].wc.wc); + OSF_COPY_MEMBER(opt[i].wc.val); + } +} + static int xt_osf_add_callback(struct net *net, struct sock *ctnl, struct sk_buff *skb, const struct nlmsghdr *nlh, const struct nlattr * const osf_attrs[])
@@ -77,11 +105,11 @@ static int xt_osf_add_callback(struct net *net, struct sock *ctnl, f = nla_data(osf_attrs[OSF_ATTR_FINGER]); - kf = kmalloc(sizeof(struct xt_osf_finger), GFP_KERNEL); + kf = kzalloc(sizeof(*kf), GFP_KERNEL); if (!kf) return -ENOMEM; - memcpy(&kf->finger, f, sizeof(struct xt_osf_user_finger)); + copy_user_finger(&kf->finger, f); list_for_each_entry(sf, &xt_osf_fingers[!!f->df], finger_entry) { if (memcmp(&sf->finger, f, sizeof(struct xt_osf_user_finger)))
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1.9.1