leandrof/linux
1
0
Fork 0
forked from Minki/linux
Code Issues Pull Requests Packages Projects Releases Wiki Activity

netfilter: nf_conntrack_irc: make sure string is terminated before calling simple_strtoul

Browse Source 
Alexey Dobriyan points out:

1. simple_strtoul() silently accepts all characters for given base even
   if result won't fit into unsigned long. This is amazing stupidity in
   itself, but

2. nf_conntrack_irc helper use simple_strtoul() for DCC request parsing.
   Data first copied into 64KB buffer, so theoretically nothing prevents
   reading past the end of it, since data comes from network given 1).

This is not actually a problem currently since we're guaranteed to have
a 0 byte in skb_shared_info or in the buffer the data is copied to, but
to make this more robust, make sure the string is actually terminated.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Patrick McHardy 2008-09-07 18:21:24 -07:00 committed by David S. Miller
parent 51807e91a7
commit e3b802ba88
1 changed files with 10 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
net/netfilter/nf_conntrack_irc.c
View File

@ -68,11 +68,21 @@ static const char *const dccprotos[] = {
static int parse_dcc(char *data, const char *data_end, u_int32_t *ip,
u_int16_t *port, char **ad_beg_p, char **ad_end_p)
{
char *tmp;
/* at least 12: "AAAAAAAA P\1\n" */
while (*data++ != ' ')
if (data > data_end - 12)
return -1;
/* Make sure we have a newline character within the packet boundaries
* because simple_strtoul parses until the first invalid character. */
for (tmp = data; tmp <= data_end; tmp++)
if (*tmp == '\n')
break;
if (tmp > data_end || *tmp != '\n')
return -1;
*ad_beg_p = data;
*ip = simple_strtoul(data, &data, 10);