netfilter: x_tables: add and use xt_check_proc_name
commit b1d0a5d0cb
upstream.
recent and hashlimit both create /proc files, but only check that
name is 0 terminated.
This can trigger WARN() from procfs when name is "" or "/".
Add helper for this and then use it for both.
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Reported-by: <syzbot+0502b00edac2a0680b61@syzkaller.appspotmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
pull/10/head
parent
2a55ad7440
commit
839a4c3b4a
|
@ -285,6 +285,8 @@ unsigned int *xt_alloc_entry_offsets(unsigned int size);
|
||||||
bool xt_find_jump_offset(const unsigned int *offsets,
|
bool xt_find_jump_offset(const unsigned int *offsets,
|
||||||
unsigned int target, unsigned int size);
|
unsigned int target, unsigned int size);
|
||||||
|
|
||||||
|
int xt_check_proc_name(const char *name, unsigned int size);
|
||||||
|
|
||||||
int xt_check_match(struct xt_mtchk_param *, unsigned int size, u_int8_t proto,
|
int xt_check_match(struct xt_mtchk_param *, unsigned int size, u_int8_t proto,
|
||||||
bool inv_proto);
|
bool inv_proto);
|
||||||
int xt_check_target(struct xt_tgchk_param *, unsigned int size, u_int8_t proto,
|
int xt_check_target(struct xt_tgchk_param *, unsigned int size, u_int8_t proto,
|
||||||
|
|
|
@ -423,6 +423,36 @@ textify_hooks(char *buf, size_t size, unsigned int mask, uint8_t nfproto)
|
||||||
return buf;
|
return buf;
|
||||||
}
|
}
|
||||||
|
|
||||||
|
/**
|
||||||
|
* xt_check_proc_name - check that name is suitable for /proc file creation
|
||||||
|
*
|
||||||
|
* @name: file name candidate
|
||||||
|
* @size: length of buffer
|
||||||
|
*
|
||||||
|
* some x_tables modules wish to create a file in /proc.
|
||||||
|
* This function makes sure that the name is suitable for this
|
||||||
|
* purpose, it checks that name is NUL terminated and isn't a 'special'
|
||||||
|
* name, like "..".
|
||||||
|
*
|
||||||
|
* returns negative number on error or 0 if name is useable.
|
||||||
|
*/
|
||||||
|
int xt_check_proc_name(const char *name, unsigned int size)
|
||||||
|
{
|
||||||
|
if (name[0] == '\0')
|
||||||
|
return -EINVAL;
|
||||||
|
|
||||||
|
if (strnlen(name, size) == size)
|
||||||
|
return -ENAMETOOLONG;
|
||||||
|
|
||||||
|
if (strcmp(name, ".") == 0 ||
|
||||||
|
strcmp(name, "..") == 0 ||
|
||||||
|
strchr(name, '/'))
|
||||||
|
return -EINVAL;
|
||||||
|
|
||||||
|
return 0;
|
||||||
|
}
|
||||||
|
EXPORT_SYMBOL(xt_check_proc_name);
|
||||||
|
|
||||||
int xt_check_match(struct xt_mtchk_param *par,
|
int xt_check_match(struct xt_mtchk_param *par,
|
||||||
unsigned int size, u_int8_t proto, bool inv_proto)
|
unsigned int size, u_int8_t proto, bool inv_proto)
|
||||||
{
|
{
|
||||||
|
|
|
@ -915,8 +915,9 @@ static int hashlimit_mt_check_v1(const struct xt_mtchk_param *par)
|
||||||
struct hashlimit_cfg3 cfg = {};
|
struct hashlimit_cfg3 cfg = {};
|
||||||
int ret;
|
int ret;
|
||||||
|
|
||||||
if (info->name[sizeof(info->name) - 1] != '\0')
|
ret = xt_check_proc_name(info->name, sizeof(info->name));
|
||||||
return -EINVAL;
|
if (ret)
|
||||||
|
return ret;
|
||||||
|
|
||||||
ret = cfg_copy(&cfg, (void *)&info->cfg, 1);
|
ret = cfg_copy(&cfg, (void *)&info->cfg, 1);
|
||||||
|
|
||||||
|
@ -933,8 +934,9 @@ static int hashlimit_mt_check_v2(const struct xt_mtchk_param *par)
|
||||||
struct hashlimit_cfg3 cfg = {};
|
struct hashlimit_cfg3 cfg = {};
|
||||||
int ret;
|
int ret;
|
||||||
|
|
||||||
if (info->name[sizeof(info->name) - 1] != '\0')
|
ret = xt_check_proc_name(info->name, sizeof(info->name));
|
||||||
return -EINVAL;
|
if (ret)
|
||||||
|
return ret;
|
||||||
|
|
||||||
ret = cfg_copy(&cfg, (void *)&info->cfg, 2);
|
ret = cfg_copy(&cfg, (void *)&info->cfg, 2);
|
||||||
|
|
||||||
|
@ -948,9 +950,11 @@ static int hashlimit_mt_check_v2(const struct xt_mtchk_param *par)
|
||||||
static int hashlimit_mt_check(const struct xt_mtchk_param *par)
|
static int hashlimit_mt_check(const struct xt_mtchk_param *par)
|
||||||
{
|
{
|
||||||
struct xt_hashlimit_mtinfo3 *info = par->matchinfo;
|
struct xt_hashlimit_mtinfo3 *info = par->matchinfo;
|
||||||
|
int ret;
|
||||||
|
|
||||||
if (info->name[sizeof(info->name) - 1] != '\0')
|
ret = xt_check_proc_name(info->name, sizeof(info->name));
|
||||||
return -EINVAL;
|
if (ret)
|
||||||
|
return ret;
|
||||||
|
|
||||||
return hashlimit_mt_check_common(par, &info->hinfo, &info->cfg,
|
return hashlimit_mt_check_common(par, &info->hinfo, &info->cfg,
|
||||||
info->name, 3);
|
info->name, 3);
|
||||||
|
|
|
@ -361,9 +361,9 @@ static int recent_mt_check(const struct xt_mtchk_param *par,
|
||||||
info->hit_count, XT_RECENT_MAX_NSTAMPS - 1);
|
info->hit_count, XT_RECENT_MAX_NSTAMPS - 1);
|
||||||
return -EINVAL;
|
return -EINVAL;
|
||||||
}
|
}
|
||||||
if (info->name[0] == '\0' ||
|
ret = xt_check_proc_name(info->name, sizeof(info->name));
|
||||||
strnlen(info->name, XT_RECENT_NAME_LEN) == XT_RECENT_NAME_LEN)
|
if (ret)
|
||||||
return -EINVAL;
|
return ret;
|
||||||
|
|
||||||
if (ip_pkt_list_tot && info->hit_count < ip_pkt_list_tot)
|
if (ip_pkt_list_tot && info->hit_count < ip_pkt_list_tot)
|
||||||
nstamp_mask = roundup_pow_of_two(ip_pkt_list_tot) - 1;
|
nstamp_mask = roundup_pow_of_two(ip_pkt_list_tot) - 1;
|
||||||
|
|
Loading…
Reference in New Issue