[PATCH 3.18 114/124] mm/mempolicy.c: fix error handling in set_mempolicy and mbind.

[Greg Kroah-Hartman]

3.18-stable review patch.  If anyone has any objections, please let me know.

--

From: Chris Salls 

commit cf01fb9985e8deb25ccf0ea54d916b8871ae0e62 upstream.

In the case that compat_get_bitmap fails we do not want to copy the
bitmap to the user as it will contain uninitialized stack data and leak
sensitive data.

Signed-off-by: Chris Salls 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman 

---
 mm/mempolicy.c |   20 
 1 file changed, 8 insertions(+), 12 deletions(-)

--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -1546,7 +1546,6 @@ COMPAT_SYSCALL_DEFINE5(get_mempolicy, in
 COMPAT_SYSCALL_DEFINE3(set_mempolicy, int, mode, compat_ulong_t __user *, 
nmask,
   compat_ulong_t, maxnode)
 {
-   long err = 0;
unsigned long __user *nm = NULL;
unsigned long nr_bits, alloc_size;
DECLARE_BITMAP(bm, MAX_NUMNODES);
@@ -1555,14 +1554,13 @@ COMPAT_SYSCALL_DEFINE3(set_mempolicy, in
alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8;
 
if (nmask) {
-   err = compat_get_bitmap(bm, nmask, nr_bits);
+   if (compat_get_bitmap(bm, nmask, nr_bits))
+   return -EFAULT;
nm = compat_alloc_user_space(alloc_size);
-   err |= copy_to_user(nm, bm, alloc_size);
+   if (copy_to_user(nm, bm, alloc_size))
+   return -EFAULT;
}
 
-   if (err)
-   return -EFAULT;
-
return sys_set_mempolicy(mode, nm, nr_bits+1);
 }
 
@@ -1570,7 +1568,6 @@ COMPAT_SYSCALL_DEFINE6(mbind, compat_ulo
   compat_ulong_t, mode, compat_ulong_t __user *, nmask,
   compat_ulong_t, maxnode, compat_ulong_t, flags)
 {
-   long err = 0;
unsigned long __user *nm = NULL;
unsigned long nr_bits, alloc_size;
nodemask_t bm;
@@ -1579,14 +1576,13 @@ COMPAT_SYSCALL_DEFINE6(mbind, compat_ulo
alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8;
 
if (nmask) {
-   err = compat_get_bitmap(nodes_addr(bm), nmask, nr_bits);
+   if (compat_get_bitmap(nodes_addr(bm), nmask, nr_bits))
+   return -EFAULT;
nm = compat_alloc_user_space(alloc_size);
-   err |= copy_to_user(nm, nodes_addr(bm), alloc_size);
+   if (copy_to_user(nm, nodes_addr(bm), alloc_size))
+   return -EFAULT;
}
 
-   if (err)
-   return -EFAULT;
-
return sys_mbind(start, len, mode, nm, nr_bits+1, flags);
 }
 

[PATCH 3.18 114/124] mm/mempolicy.c: fix error handling in set_mempolicy and mbind.

[Greg Kroah-Hartman]

3.18-stable review patch.  If anyone has any objections, please let me know.

--

From: Chris Salls 

commit cf01fb9985e8deb25ccf0ea54d916b8871ae0e62 upstream.

In the case that compat_get_bitmap fails we do not want to copy the
bitmap to the user as it will contain uninitialized stack data and leak
sensitive data.

Signed-off-by: Chris Salls 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman 

---
 mm/mempolicy.c |   20 
 1 file changed, 8 insertions(+), 12 deletions(-)

--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -1546,7 +1546,6 @@ COMPAT_SYSCALL_DEFINE5(get_mempolicy, in
 COMPAT_SYSCALL_DEFINE3(set_mempolicy, int, mode, compat_ulong_t __user *, 
nmask,
   compat_ulong_t, maxnode)
 {
-   long err = 0;
unsigned long __user *nm = NULL;
unsigned long nr_bits, alloc_size;
DECLARE_BITMAP(bm, MAX_NUMNODES);
@@ -1555,14 +1554,13 @@ COMPAT_SYSCALL_DEFINE3(set_mempolicy, in
alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8;
 
if (nmask) {
-   err = compat_get_bitmap(bm, nmask, nr_bits);
+   if (compat_get_bitmap(bm, nmask, nr_bits))
+   return -EFAULT;
nm = compat_alloc_user_space(alloc_size);
-   err |= copy_to_user(nm, bm, alloc_size);
+   if (copy_to_user(nm, bm, alloc_size))
+   return -EFAULT;
}
 
-   if (err)
-   return -EFAULT;
-
return sys_set_mempolicy(mode, nm, nr_bits+1);
 }
 
@@ -1570,7 +1568,6 @@ COMPAT_SYSCALL_DEFINE6(mbind, compat_ulo
   compat_ulong_t, mode, compat_ulong_t __user *, nmask,
   compat_ulong_t, maxnode, compat_ulong_t, flags)
 {
-   long err = 0;
unsigned long __user *nm = NULL;
unsigned long nr_bits, alloc_size;
nodemask_t bm;
@@ -1579,14 +1576,13 @@ COMPAT_SYSCALL_DEFINE6(mbind, compat_ulo
alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8;
 
if (nmask) {
-   err = compat_get_bitmap(nodes_addr(bm), nmask, nr_bits);
+   if (compat_get_bitmap(nodes_addr(bm), nmask, nr_bits))
+   return -EFAULT;
nm = compat_alloc_user_space(alloc_size);
-   err |= copy_to_user(nm, nodes_addr(bm), alloc_size);
+   if (copy_to_user(nm, nodes_addr(bm), alloc_size))
+   return -EFAULT;
}
 
-   if (err)
-   return -EFAULT;
-
return sys_mbind(start, len, mode, nm, nr_bits+1, flags);
 }