diff options
authorJohn Johansen <john.johansen@canonical.com>2010-10-09 00:47:53 -0700
committerJames Morris <jmorris@namei.org>2010-10-21 10:12:46 +1100
commit3ed02ada2a5e695e2fbb5e4a0008cfcb0f50feaa (patch)
parent9f1c1d426b0402b25cd0d7ca719ffc8e20e46d5f (diff)
AppArmor: Ensure the size of the copy is < the buffer allocated to hold it
Actually I think in this case the appropriate thing to do is to BUG as there is currently a case (remove) where the alloc_size needs to be larger than the copy_size, and if copy_size is ever greater than alloc_size there is a mistake in the caller code. Signed-off-by: John Johansen <john.johansen@canonical.com> Acked-by: Kees Cook <kees.cook@canonical.com> Signed-off-by: James Morris <jmorris@namei.org>
1 files changed, 3 insertions, 1 deletions
diff --git a/security/apparmor/apparmorfs.c b/security/apparmor/apparmorfs.c
index 7320331b44a..544ff5837cb 100644
--- a/security/apparmor/apparmorfs.c
+++ b/security/apparmor/apparmorfs.c
@@ -29,7 +29,7 @@
* aa_simple_write_to_buffer - common routine for getting policy from user
* @op: operation doing the user buffer copy
* @userbuf: user buffer to copy data from (NOT NULL)
- * @alloc_size: size of user buffer
+ * @alloc_size: size of user buffer (REQUIRES: @alloc_size >= @copy_size)
* @copy_size: size of data to copy from user buffer
* @pos: position write is at in the file (NOT NULL)
@@ -42,6 +42,8 @@ static char *aa_simple_write_to_buffer(int op, const char __user *userbuf,
char *data;
+ BUG_ON(copy_size > alloc_size);
if (*pos != 0)
/* only writes from pos 0, that is complete writes */
return ERR_PTR(-ESPIPE);