Bug#410697: linux-image-2.6.18-4-amd64: 32-bit iptables doesn't work with xt_limit module from amd64 kernel
Package: linux-image-2.6.18-4-amd64
Version: 2.6.18.dfsg.1-10
Severity: wishlist
Tags: patch
Hello,
Please consider adding compat code to debian kernel to allow 32bit
iptables work with module limit (-m limit option).
Now, on kernel version 2.6.18-4-amd64 (2.6.18.dfsg.1-10):
# iptables -A FORWARD -m limit --limit 5
iptables: Invalid argument
kernel log fragment:
ip_tables: limit match: invalid size 40 != 28
Using 32-bit userland and amd64 kernel is very useful and quite popular
combination.
Mainline kernel added xt_limit compat code in post-2.6.18 versions,
git patches:
[NETFILTER]: x_tables: simplify compat API
9fa492cdc160cd27ce1046cb36f47d3b2b1efa21
[NETFILTER]: xt_limit: add compat conversion functions
02c63cf777c331121bfb6e9c1440a9835ad2f2a8
Slightly modified versions of those patches I attach.
Modifications are necessary to avoid applying
52d9c42ef2563d2c420eb23b96bf5a4cae9e167b and
4470bbc749e5551cce914529309456f631e25120 which are quite large.
Unfortunately patch "simplify compat API" modifies kernel ABI.
Regards,
Rafał Kupka
--- a/include/linux/netfilter/x_tables.h
+++ b/include/linux/netfilter/x_tables.h
@@ -138,12 +138,6 @@ struct xt_counters_info
#define ASSERT_WRITE_LOCK(x)
#include <linux/netfilter_ipv4/listhelp.h>
-#ifdef CONFIG_COMPAT
-#define COMPAT_TO_USER 1
-#define COMPAT_FROM_USER -1
-#define COMPAT_CALC_SIZE 0
-#endif
-
struct xt_match
{
struct list_head list;
@@ -176,7 +170,8 @@ struct xt_match
void (*destroy)(const struct xt_match *match, void *matchinfo);
/* Called when userspace align differs from kernel space one */
- int (*compat)(void *match, void **dstptr, int *size, int convert);
+ void (*compat_from_user)(void *dst, void *src);
+ int (*compat_to_user)(void __user *dst, void *src);
/* Set this to THIS_MODULE if you are a module, otherwise NULL */
struct module *me;
@@ -186,6 +181,7 @@ struct xt_match
char *table;
unsigned int matchsize;
+ unsigned int compatsize;
unsigned int hooks;
unsigned short proto;
@@ -224,13 +220,15 @@ struct xt_target
void (*destroy)(const struct xt_target *target, void *targinfo);
/* Called when userspace align differs from kernel space one */
- int (*compat)(void *target, void **dstptr, int *size, int convert);
+ void (*compat_from_user)(void *dst, void *src);
+ int (*compat_to_user)(void __user *dst, void *src);
/* Set this to THIS_MODULE if you are a module, otherwise NULL */
struct module *me;
char *table;
unsigned int targetsize;
+ unsigned int compatsize;
unsigned int hooks;
unsigned short proto;
@@ -387,9 +385,18 @@ struct compat_xt_counters_info
extern void xt_compat_lock(int af);
extern void xt_compat_unlock(int af);
-extern int xt_compat_match(void *match, void **dstptr, int *size, int convert);
-extern int xt_compat_target(void *target, void **dstptr, int *size,
- int convert);
+
+extern int xt_compat_match_offset(struct xt_match *match);
+extern void xt_compat_match_from_user(struct xt_entry_match *m,
+ void **dstptr, int *size);
+extern int xt_compat_match_to_user(struct xt_entry_match *m,
+ void * __user *dstptr, int *size);
+
+extern int xt_compat_target_offset(struct xt_target *target);
+extern void xt_compat_target_from_user(struct xt_entry_target *t,
+ void **dstptr, int *size);
+extern int xt_compat_target_to_user(struct xt_entry_target *t,
+ void * __user *dstptr, int *size);
#endif /* CONFIG_COMPAT */
#endif /* __KERNEL__ */
diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
index 673581d..800067d 100644
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -942,73 +942,28 @@ static short compat_calc_jump(u_int16_t offset)
return delta;
}
-struct compat_ipt_standard_target
+static void compat_standard_from_user(void *dst, void *src)
{
- struct compat_xt_entry_target target;
- compat_int_t verdict;
-};
-
-struct compat_ipt_standard
-{
- struct compat_ipt_entry entry;
- struct compat_ipt_standard_target target;
-};
+ int v = *(compat_int_t *)src;
-#define IPT_ST_LEN XT_ALIGN(sizeof(struct ipt_standard_target))
-#define IPT_ST_COMPAT_LEN COMPAT_XT_ALIGN(sizeof(struct compat_ipt_standard_target))
-#define IPT_ST_OFFSET (IPT_ST_LEN - IPT_ST_COMPAT_LEN)
+ if (v > 0)
+ v += compat_calc_jump(v);
+ memcpy(dst, &v, sizeof(v));
+}
-static int compat_ipt_standard_fn(void *target,
- void **dstptr, int *size, int convert)
+static int compat_standard_to_user(void __user *dst, void *src)
{
- struct compat_ipt_standard_target compat_st, *pcompat_st;
- struct ipt_standard_target st, *pst;
- int ret;
+ compat_int_t cv = *(int *)src;
- ret = 0;
- switch (convert) {
- case COMPAT_TO_USER:
- pst = target;
- memcpy(&compat_st.target, &pst->target,
- sizeof(compat_st.target));
- compat_st.verdict = pst->verdict;
- if (compat_st.verdict > 0)
- compat_st.verdict -=
- compat_calc_jump(compat_st.verdict);
- compat_st.target.u.user.target_size = IPT_ST_COMPAT_LEN;
- if (copy_to_user(*dstptr, &compat_st, IPT_ST_COMPAT_LEN))
- ret = -EFAULT;
- *size -= IPT_ST_OFFSET;
- *dstptr += IPT_ST_COMPAT_LEN;
- break;
- case COMPAT_FROM_USER:
- pcompat_st = target;
- memcpy(&st.target, &pcompat_st->target, IPT_ST_COMPAT_LEN);
- st.verdict = pcompat_st->verdict;
- if (st.verdict > 0)
- st.verdict += compat_calc_jump(st.verdict);
- st.target.u.user.target_size = IPT_ST_LEN;
- memcpy(*dstptr, &st, IPT_ST_LEN);
- *size += IPT_ST_OFFSET;
- *dstptr += IPT_ST_LEN;
- break;
- case COMPAT_CALC_SIZE:
- *size += IPT_ST_OFFSET;
- break;
- default:
- ret = -ENOPROTOOPT;
- break;
- }
- return ret;
+ if (cv > 0)
+ cv -= compat_calc_jump(cv);
+ return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0;
}
static inline int
compat_calc_match(struct ipt_entry_match *m, int * size)
{
- if (m->u.kernel.match->compat)
- m->u.kernel.match->compat(m, NULL, size, COMPAT_CALC_SIZE);
- else
- xt_compat_match(m, NULL, size, COMPAT_CALC_SIZE);
+ *size += xt_compat_match_offset(m->u.kernel.match);
return 0;
}
@@ -1023,10 +978,7 @@ static int compat_calc_entry(struct ipt_entry *e, struct xt_table_info *info,
entry_offset = (void *)e - base;
IPT_MATCH_ITERATE(e, compat_calc_match, &off);
t = ipt_get_target(e);
- if (t->u.kernel.target->compat)
- t->u.kernel.target->compat(t, NULL, &off, COMPAT_CALC_SIZE);
- else
- xt_compat_target(t, NULL, &off, COMPAT_CALC_SIZE);
+ off += xt_compat_target_offset(t->u.kernel.target);
newinfo->size -= off;
ret = compat_add_offset(entry_offset, off);
if (ret)
@@ -1412,17 +1364,13 @@ struct compat_ipt_replace {
};
static inline int compat_copy_match_to_user(struct ipt_entry_match *m,
- void __user **dstptr, compat_uint_t *size)
+ void * __user *dstptr, compat_uint_t *size)
{
- if (m->u.kernel.match->compat)
- return m->u.kernel.match->compat(m, dstptr, size,
- COMPAT_TO_USER);
- else
- return xt_compat_match(m, dstptr, size, COMPAT_TO_USER);
+ return xt_compat_match_to_user(m, dstptr, size);
}
static int compat_copy_entry_to_user(struct ipt_entry *e,
- void __user **dstptr, compat_uint_t *size)
+ void * __user *dstptr, compat_uint_t *size)
{
struct ipt_entry_target __user *t;
struct compat_ipt_entry __user *ce;
@@ -1442,11 +1390,7 @@ static int compat_copy_entry_to_user(struct ipt_entry *e,
if (ret)
goto out;
t = ipt_get_target(e);
- if (t->u.kernel.target->compat)
- ret = t->u.kernel.target->compat(t, dstptr, size,
- COMPAT_TO_USER);
- else
- ret = xt_compat_target(t, dstptr, size, COMPAT_TO_USER);
+ ret = xt_compat_target_to_user(t, dstptr, size);
if (ret)
goto out;
ret = -EFAULT;
@@ -1478,11 +1422,7 @@ compat_check_calc_match(struct ipt_entry_match *m,
return match ? PTR_ERR(match) : -ENOENT;
}
m->u.kernel.match = match;
-
- if (m->u.kernel.match->compat)
- m->u.kernel.match->compat(m, NULL, size, COMPAT_CALC_SIZE);
- else
- xt_compat_match(m, NULL, size, COMPAT_CALC_SIZE);
+ *size += xt_compat_match_offset(match);
(*i)++;
return 0;
@@ -1543,10 +1483,7 @@ check_compat_entry_size_and_hooks(struct ipt_entry *e,
}
t->u.kernel.target = target;
- if (t->u.kernel.target->compat)
- t->u.kernel.target->compat(t, NULL, &off, COMPAT_CALC_SIZE);
- else
- xt_compat_target(t, NULL, &off, COMPAT_CALC_SIZE);
+ off += xt_compat_target_offset(target);
*size += off;
ret = compat_add_offset(entry_offset, off);
if (ret)
@@ -1584,10 +1521,7 @@ static inline int compat_copy_match_from_user(struct ipt_entry_match *m,
dm = (struct ipt_entry_match *)*dstptr;
match = m->u.kernel.match;
- if (match->compat)
- match->compat(m, dstptr, size, COMPAT_FROM_USER);
- else
- xt_compat_match(m, dstptr, size, COMPAT_FROM_USER);
+ xt_compat_match_from_user(m, dstptr, size);
ret = xt_check_match(match, AF_INET, dm->u.match_size - sizeof(*dm),
name, hookmask, ip->proto,
@@ -1635,10 +1569,7 @@ static int compat_copy_entry_from_user(struct ipt_entry *e, void **dstptr,
de->target_offset = e->target_offset - (origsize - *size);
t = ipt_get_target(e);
target = t->u.kernel.target;
- if (target->compat)
- target->compat(t, dstptr, size, COMPAT_FROM_USER);
- else
- xt_compat_target(t, dstptr, size, COMPAT_FROM_USER);
+ xt_compat_target_from_user(t, dstptr, size);
de->next_offset = e->next_offset - (origsize - *size);
for (h = 0; h < NF_IP_NUMHOOKS; h++) {
@@ -2205,7 +2136,9 @@ static struct ipt_target ipt_standard_target = {
.targetsize = sizeof(int),
.family = AF_INET,
#ifdef CONFIG_COMPAT
- .compat = &compat_ipt_standard_fn,
+ .compatsize = sizeof(compat_int_t),
+ .compat_from_user = compat_standard_from_user,
+ .compat_to_user = compat_standard_to_user,
#endif
};
diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c
index be7baf4..58522fc 100644
--- a/net/netfilter/x_tables.c
+++ b/net/netfilter/x_tables.c
@@ -333,52 +333,65 @@ int xt_check_match(const struct xt_match *match, unsigned short family,
EXPORT_SYMBOL_GPL(xt_check_match);
#ifdef CONFIG_COMPAT
-int xt_compat_match(void *match, void **dstptr, int *size, int convert)
+int xt_compat_match_offset(struct xt_match *match)
{
- struct xt_match *m;
- struct compat_xt_entry_match *pcompat_m;
- struct xt_entry_match *pm;
- u_int16_t msize;
- int off, ret;
+ u_int16_t csize = match->compatsize ? : match->matchsize;
+ return XT_ALIGN(match->matchsize) - COMPAT_XT_ALIGN(csize);
+}
+EXPORT_SYMBOL_GPL(xt_compat_match_offset);
- ret = 0;
- m = ((struct xt_entry_match *)match)->u.kernel.match;
- off = XT_ALIGN(m->matchsize) - COMPAT_XT_ALIGN(m->matchsize);
- switch (convert) {
- case COMPAT_TO_USER:
- pm = (struct xt_entry_match *)match;
- msize = pm->u.user.match_size;
- if (copy_to_user(*dstptr, pm, msize)) {
- ret = -EFAULT;
- break;
- }
- msize -= off;
- if (put_user(msize, (u_int16_t *)*dstptr))
- ret = -EFAULT;
- *size -= off;
- *dstptr += msize;
- break;
- case COMPAT_FROM_USER:
- pcompat_m = (struct compat_xt_entry_match *)match;
- pm = (struct xt_entry_match *)*dstptr;
- msize = pcompat_m->u.user.match_size;
- memcpy(pm, pcompat_m, msize);
- msize += off;
- pm->u.user.match_size = msize;
- *size += off;
- *dstptr += msize;
- break;
- case COMPAT_CALC_SIZE:
- *size += off;
- break;
- default:
- ret = -ENOPROTOOPT;
- break;
+void xt_compat_match_from_user(struct xt_entry_match *m, void **dstptr,
+ int *size)
+{
+ struct xt_match *match = m->u.kernel.match;
+ struct compat_xt_entry_match *cm = (struct compat_xt_entry_match *)m;
+ int pad, off = xt_compat_match_offset(match);
+ u_int16_t msize = cm->u.user.match_size;
+
+ m = *dstptr;
+ memcpy(m, cm, sizeof(*cm));
+ if (match->compat_from_user)
+ match->compat_from_user(m->data, cm->data);
+ else
+ memcpy(m->data, cm->data, msize - sizeof(*cm));
+ pad = XT_ALIGN(match->matchsize) - match->matchsize;
+ if (pad > 0)
+ memset(m->data + match->matchsize, 0, pad);
+
+ msize += off;
+ m->u.user.match_size = msize;
+
+ *size += off;
+ *dstptr += msize;
+}
+EXPORT_SYMBOL_GPL(xt_compat_match_from_user);
+
+int xt_compat_match_to_user(struct xt_entry_match *m, void __user **dstptr,
+ int *size)
+{
+ struct xt_match *match = m->u.kernel.match;
+ struct compat_xt_entry_match __user *cm = *dstptr;
+ int off = xt_compat_match_offset(match);
+ u_int16_t msize = m->u.user.match_size - off;
+
+ if (copy_to_user(cm, m, sizeof(*cm)) ||
+ put_user(msize, &cm->u.user.match_size))
+ return -EFAULT;
+
+ if (match->compat_to_user) {
+ if (match->compat_to_user((void __user *)cm->data, m->data))
+ return -EFAULT;
+ } else {
+ if (copy_to_user(cm->data, m->data, msize - sizeof(*cm)))
+ return -EFAULT;
}
- return ret;
+
+ *size -= off;
+ *dstptr += msize;
+ return 0;
}
-EXPORT_SYMBOL_GPL(xt_compat_match);
-#endif
+EXPORT_SYMBOL_GPL(xt_compat_match_to_user);
+#endif /* CONFIG_COMPAT */
int xt_check_target(const struct xt_target *target, unsigned short family,
unsigned int size, const char *table, unsigned int hook_mask,
@@ -410,51 +423,64 @@ int xt_check_target(const struct xt_target *target, unsigned short family,
EXPORT_SYMBOL_GPL(xt_check_target);
#ifdef CONFIG_COMPAT
-int xt_compat_target(void *target, void **dstptr, int *size, int convert)
+int xt_compat_target_offset(struct xt_target *target)
{
- struct xt_target *t;
- struct compat_xt_entry_target *pcompat;
- struct xt_entry_target *pt;
- u_int16_t tsize;
- int off, ret;
+ u_int16_t csize = target->compatsize ? : target->targetsize;
+ return XT_ALIGN(target->targetsize) - COMPAT_XT_ALIGN(csize);
+}
+EXPORT_SYMBOL_GPL(xt_compat_target_offset);
- ret = 0;
- t = ((struct xt_entry_target *)target)->u.kernel.target;
- off = XT_ALIGN(t->targetsize) - COMPAT_XT_ALIGN(t->targetsize);
- switch (convert) {
- case COMPAT_TO_USER:
- pt = (struct xt_entry_target *)target;
- tsize = pt->u.user.target_size;
- if (copy_to_user(*dstptr, pt, tsize)) {
- ret = -EFAULT;
- break;
- }
- tsize -= off;
- if (put_user(tsize, (u_int16_t *)*dstptr))
- ret = -EFAULT;
- *size -= off;
- *dstptr += tsize;
- break;
- case COMPAT_FROM_USER:
- pcompat = (struct compat_xt_entry_target *)target;
- pt = (struct xt_entry_target *)*dstptr;
- tsize = pcompat->u.user.target_size;
- memcpy(pt, pcompat, tsize);
- tsize += off;
- pt->u.user.target_size = tsize;
- *size += off;
- *dstptr += tsize;
- break;
- case COMPAT_CALC_SIZE:
- *size += off;
- break;
- default:
- ret = -ENOPROTOOPT;
- break;
+void xt_compat_target_from_user(struct xt_entry_target *t, void **dstptr,
+ int *size)
+{
+ struct xt_target *target = t->u.kernel.target;
+ struct compat_xt_entry_target *ct = (struct compat_xt_entry_target *)t;
+ int pad, off = xt_compat_target_offset(target);
+ u_int16_t tsize = ct->u.user.target_size;
+
+ t = *dstptr;
+ memcpy(t, ct, sizeof(*ct));
+ if (target->compat_from_user)
+ target->compat_from_user(t->data, ct->data);
+ else
+ memcpy(t->data, ct->data, tsize - sizeof(*ct));
+ pad = XT_ALIGN(target->targetsize) - target->targetsize;
+ if (pad > 0)
+ memset(t->data + target->targetsize, 0, pad);
+
+ tsize += off;
+ t->u.user.target_size = tsize;
+
+ *size += off;
+ *dstptr += tsize;
+}
+EXPORT_SYMBOL_GPL(xt_compat_target_from_user);
+
+int xt_compat_target_to_user(struct xt_entry_target *t, void __user **dstptr,
+ int *size)
+{
+ struct xt_target *target = t->u.kernel.target;
+ struct compat_xt_entry_target __user *ct = *dstptr;
+ int off = xt_compat_target_offset(target);
+ u_int16_t tsize = t->u.user.target_size - off;
+
+ if (copy_to_user(ct, t, sizeof(*ct)) ||
+ put_user(tsize, &ct->u.user.target_size))
+ return -EFAULT;
+
+ if (target->compat_to_user) {
+ if (target->compat_to_user((void __user *)ct->data, t->data))
+ return -EFAULT;
+ } else {
+ if (copy_to_user(ct->data, t->data, tsize - sizeof(*ct)))
+ return -EFAULT;
}
- return ret;
+
+ *size -= off;
+ *dstptr += tsize;
+ return 0;
}
-EXPORT_SYMBOL_GPL(xt_compat_target);
+EXPORT_SYMBOL_GPL(xt_compat_target_to_user);
#endif
struct xt_table_info *xt_alloc_table_info(unsigned int size)
--- a/net/netfilter/xt_limit.c 2006-09-20 03:42:06.000000000 +0000
+++ b/net/netfilter/xt_limit.c 2007-02-11 09:16:35.000000000 +0000
@@ -136,12 +136,61 @@
return 1;
}
+#ifdef CONFIG_COMPAT
+struct compat_xt_rateinfo {
+ u_int32_t avg;
+ u_int32_t burst;
+
+ compat_ulong_t prev;
+ u_int32_t credit;
+ u_int32_t credit_cap, cost;
+
+ u_int32_t master;
+};
+
+/* To keep the full "prev" timestamp, the upper 32 bits are stored in the
+ * master pointer, which does not need to be preserved. */
+static void compat_from_user(void *dst, void *src)
+{
+ struct compat_xt_rateinfo *cm = src;
+ struct xt_rateinfo m = {
+ .avg = cm->avg,
+ .burst = cm->burst,
+ .prev = cm->prev | (unsigned long)cm->master << 32,
+ .credit = cm->credit,
+ .credit_cap = cm->credit_cap,
+ .cost = cm->cost,
+ };
+ memcpy(dst, &m, sizeof(m));
+}
+
+static int compat_to_user(void __user *dst, void *src)
+{
+ struct xt_rateinfo *m = src;
+ struct compat_xt_rateinfo cm = {
+ .avg = m->avg,
+ .burst = m->burst,
+ .prev = m->prev,
+ .credit = m->credit,
+ .credit_cap = m->credit_cap,
+ .cost = m->cost,
+ .master = m->prev >> 32,
+ };
+ return copy_to_user(dst, &cm, sizeof(cm)) ? -EFAULT : 0;
+}
+#endif /* CONFIG_COMPAT */
+
static struct xt_match ipt_limit_reg = {
.name = "limit",
.match = ipt_limit_match,
.matchsize = sizeof(struct xt_rateinfo),
.checkentry = ipt_limit_checkentry,
.family = AF_INET,
+#ifdef CONFIG_COMPAT
+ .compatsize = sizeof(struct compat_xt_rateinfo),
+ .compat_from_user = compat_from_user,
+ .compat_to_user = compat_to_user,
+#endif
.me = THIS_MODULE,
};
static struct xt_match limit6_reg = {
@@ -150,6 +199,11 @@
.matchsize = sizeof(struct xt_rateinfo),
.checkentry = ipt_limit_checkentry,
.family = AF_INET6,
+#ifdef CONFIG_COMPAT
+ .compatsize = sizeof(struct compat_xt_rateinfo),
+ .compat_from_user = compat_from_user,
+ .compat_to_user = compat_to_user,
+#endif
.me = THIS_MODULE,
};
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