xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

[NETFILTER]: Fix {ip,ip6,arp}_tables hook validation

Browse Source 
Commit 590bdf7fd2 introduced a regression
in match/target hook validation. mark_source_chains builds a bitmask
for each rule representing the hooks it can be reached from, which is
then used by the matches and targets to make sure they are only called
from valid hooks. The patch moved the match/target specific validation
before the mark_source_chains call, at which point the mask is always zero.

This patch returns back to the old order and moves the standard checks
to mark_source_chains. This allows to get rid of a special case for
standard targets as a nice side-effect.

Signed-off-by: Dmitry Mishin <dim@openvz.org>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Dmitry Mishin
2006-12-05 13:43:50 -08:00
committed by David S. Miller
parent 79066ad32b
commit 74c9c0c17d
3 changed files with 72 additions and 103 deletions
Download Patch File Download Diff File Expand all files Collapse all files

59
net/ipv6/netfilter/ip6_tables.c
View File

@@ -440,6 +440,13 @@ mark_source_chains(struct xt_table_info *newinfo,
&& unconditional(&e->ipv6)) {
unsigned int oldpos, size;
if (t->verdict < -NF_MAX_VERDICT - 1) {
duprintf("mark_source_chains: bad "
"negative verdict (%i)\n",
t->verdict);
return 0;
}
/* Return: backtrack through the last
big jump. */
do {
@@ -477,6 +484,13 @@ mark_source_chains(struct xt_table_info *newinfo,
if (strcmp(t->target.u.user.name,
IP6T_STANDARD_TARGET) == 0
&& newpos >= 0) {
if (newpos > newinfo->size -
sizeof(struct ip6t_entry)) {
duprintf("mark_source_chains: "
"bad verdict (%i)\n",
newpos);
return 0;
}
/* This a jump; chase it. */
duprintf("Jump rule %u -> %u\n",
pos, newpos);
@@ -508,27 +522,6 @@ cleanup_match(struct ip6t_entry_match *m, unsigned int *i)
return 0;
}
static inline int
standard_check(const struct ip6t_entry_target *t,
unsigned int max_offset)
{
struct ip6t_standard_target *targ = (void *)t;
/* Check standard info. */
if (targ->verdict >= 0
&& targ->verdict > max_offset - sizeof(struct ip6t_entry)) {
duprintf("ip6t_standard_check: bad verdict (%i)\n",
targ->verdict);
return 0;
}
if (targ->verdict < -NF_MAX_VERDICT - 1) {
duprintf("ip6t_standard_check: bad negative verdict (%i)\n",
targ->verdict);
return 0;
}
return 1;
}
static inline int
check_match(struct ip6t_entry_match *m,
const char *name,
@@ -616,12 +609,7 @@ check_entry(struct ip6t_entry *e, const char *name, unsigned int size,
if (ret)
goto err;
if (t->u.kernel.target == &ip6t_standard_target) {
if (!standard_check(t, size)) {
ret = -EINVAL;
goto err;
}
} else if (t->u.kernel.target->checkentry
if (t->u.kernel.target->checkentry
&& !t->u.kernel.target->checkentry(name, e, target, t->data,
e->comefrom)) {
duprintf("ip_tables: check failed for `%s'.\n",
@@ -758,17 +746,19 @@ translate_table(const char *name,
}
}
if (!mark_source_chains(newinfo, valid_hooks, entry0))
return -ELOOP;
/* Finally, each sanity check must pass */
i = 0;
ret = IP6T_ENTRY_ITERATE(entry0, newinfo->size,
check_entry, name, size, &i);
if (ret != 0)
goto cleanup;
ret = -ELOOP;
if (!mark_source_chains(newinfo, valid_hooks, entry0))
goto cleanup;
if (ret != 0) {
IP6T_ENTRY_ITERATE(entry0, newinfo->size,
cleanup_entry, &i);
return ret;
}
/* And one copy for every other CPU */
for_each_possible_cpu(i) {
@@ -777,9 +767,6 @@ translate_table(const char *name,
}
return 0;
cleanup:
IP6T_ENTRY_ITERATE(entry0, newinfo->size, cleanup_entry, &i);
return ret;
}
/* Gets counters. */