For NUL terminated string, better always be sure of ended by '\0'.
'pm' is 'struct ulog_packet_msg_t' which may be copied to user mode
(defined in "include/uapi/..."), so can not use strlcpy() instead of.
Signed-off-by: Chen Gang <gang.chen@xxxxxxxxxxx>
---
net/ipv4/netfilter/ipt_ULOG.c | 27 ++++++++++++++++-----------
1 files changed, 16 insertions(+), 11 deletions(-)
diff --git a/net/ipv4/netfilter/ipt_ULOG.c b/net/ipv4/netfilter/ipt_ULOG.c
index f8a222cb..4a93382 100644
--- a/net/ipv4/netfilter/ipt_ULOG.c
+++ b/net/ipv4/netfilter/ipt_ULOG.c
@@ -231,11 +231,13 @@ static void ipt_ulog_packet(unsigned int hooknum,
put_unaligned(tv.tv_usec, &pm->timestamp_usec);
put_unaligned(skb->mark, &pm->mark);
pm->hook = hooknum;
- if (prefix != NULL)
- strncpy(pm->prefix, prefix, sizeof(pm->prefix));
- else if (loginfo->prefix[0] != '\0')
- strncpy(pm->prefix, loginfo->prefix, sizeof(pm->prefix));
- else
+ if (prefix != NULL) {
+ strncpy(pm->prefix, prefix, sizeof(pm->prefix) - 1);
+ pm->prefix[sizeof(pm->prefix) - 1] = '\0';
+ } else if (loginfo->prefix[0] != '\0') {
+ strncpy(pm->prefix, loginfo->prefix, sizeof(pm->prefix) - 1);
+ pm->prefix[sizeof(pm->prefix) - 1] = '\0';
+ } else
*(pm->prefix) = '\0';
if (in && in->hard_header_len > 0 &&
@@ -246,14 +248,17 @@ static void ipt_ulog_packet(unsigned int hooknum,
} else
pm->mac_len = 0;
- if (in)
- strncpy(pm->indev_name, in->name, sizeof(pm->indev_name));
- else
+ if (in) {
+ strncpy(pm->indev_name, in->name, sizeof(pm->indev_name) - 1);
+ pm->indev_name[sizeof(pm->indev_name) - 1] = '\0';
+ } else
pm->indev_name[0] = '\0';
- if (out)
- strncpy(pm->outdev_name, out->name, sizeof(pm->outdev_name));
- else
+ if (out) {
+ strncpy(pm->outdev_name, out->name,
+ sizeof(pm->outdev_name) - 1);
+ pm->outdev_name[sizeof(pm->outdev_name) - 1] = '\0';
+ } else
pm->outdev_name[0] = '\0';
/* copy_len <= skb->len, so can't fail. */
--
1.7.7.6
--
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