[PATCH 4.11 57/58] netfilter: xtables: fix build failure from COMPAT_XT_ALIGN outside CONFIG_COMPAT

Greg Kroah-Hartman
2017-06-27T14:19:41Z

From: Willem de Bruijn <willemb@google.com>

commit 751a9c763849f5859cb69ea44b0430d00672f637 upstream.

The patch in the Fixes references COMPAT_XT_ALIGN in the definition
of XT_DATA_TO_USER, outside an #ifdef CONFIG_COMPAT block.

Split XT_DATA_TO_USER into separate compat and non compat variants and
define the first inside an CONFIG_COMPAT block.

This simplifies both variants by removing branches inside the macro.

Fixes: 324318f0248c ("netfilter: xtables: zero padding in data_to_user")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: Florian Westphal <fw@strlen.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
net/netfilter/x_tables.c | 21 +++++++++++++--------
1 file changed, 13 insertions(+), 8 deletions(-)

--- a/net/netfilter/x_tables.c
+++ b/net/netfilter/x_tables.c
@@ -296,18 +296,17 @@ int xt_data_to_user(void __user *dst, co
}
EXPORT_SYMBOL_GPL(xt_data_to_user);

-#define XT_DATA_TO_USER(U, K, TYPE, C_SIZE) \
+#define XT_DATA_TO_USER(U, K, TYPE) \
xt_data_to_user(U->data, K->data, \
K->u.kernel.TYPE->usersize, \
- C_SIZE ? : K->u.kernel.TYPE->TYPE##size, \
- C_SIZE ? COMPAT_XT_ALIGN(C_SIZE) : \
- XT_ALIGN(K->u.kernel.TYPE->TYPE##size))
+ K->u.kernel.TYPE->TYPE##size, \
+ XT_ALIGN(K->u.kernel.TYPE->TYPE##size))

int xt_match_to_user(const struct xt_entry_match *m,
struct xt_entry_match __user *u)
{
return XT_OBJ_TO_USER(u, m, match, 0) ||
- XT_DATA_TO_USER(u, m, match, 0);
+ XT_DATA_TO_USER(u, m, match);
}
EXPORT_SYMBOL_GPL(xt_match_to_user);

@@ -315,7 +314,7 @@ int xt_target_to_user(const struct xt_en
struct xt_entry_target __user *u)
{
return XT_OBJ_TO_USER(u, t, target, 0) ||
- XT_DATA_TO_USER(u, t, target, 0);
+ XT_DATA_TO_USER(u, t, target);
}
EXPORT_SYMBOL_GPL(xt_target_to_user);

@@ -614,6 +613,12 @@ void xt_compat_match_from_user(struct xt
}
EXPORT_SYMBOL_GPL(xt_compat_match_from_user);

+#define COMPAT_XT_DATA_TO_USER(U, K, TYPE, C_SIZE) \
+ xt_data_to_user(U->data, K->data, \
+ K->u.kernel.TYPE->usersize, \
+ C_SIZE, \
+ COMPAT_XT_ALIGN(C_SIZE))
+
int xt_compat_match_to_user(const struct xt_entry_match *m,
void __user **dstptr, unsigned int *size)
{
@@ -629,7 +634,7 @@ int xt_compat_match_to_user(const struct
if (match->compat_to_user((void __user *)cm->data, m->data))
return -EFAULT;
} else {
- if (XT_DATA_TO_USER(cm, m, match, msize - sizeof(*cm)))
+ if (COMPAT_XT_DATA_TO_USER(cm, m, match, msize - sizeof(*cm)))
return -EFAULT;
}

@@ -984,7 +989,7 @@ int xt_compat_target_to_user(const struc
if (target->compat_to_user((void __user *)ct->data, t->data))
return -EFAULT;
} else {
- if (XT_DATA_TO_USER(ct, t, target, tsize - sizeof(*ct)))
+ if (COMPAT_XT_DATA_TO_USER(ct, t, target, tsize - sizeof(*ct)))
return -EFAULT;
}