From a608ca21f58ee44df5a71ba140e98498f3ebc2cd Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Wed, 10 Oct 2012 15:25:26 -0400 Subject: vfs: allocate page instead of names_cache buffer in mount_block_root First, it's incorrect to call putname() after __getname_gfp() since the bare __getname_gfp() call skips the auditing code, while putname() doesn't. mount_block_root allocates a PATH_MAX buffer via __getname_gfp, and then calls get_fs_names to fill the buffer. That function can call get_filesystem_list which assumes that that buffer is a full page in size. On arches where PAGE_SIZE != 4k, then this could potentially overrun. In practice, it's hard to imagine the list of filesystem names even approaching 4k, but it's best to be safe. Just allocate a page for this purpose instead. With this, we can also remove the __getname_gfp() definition since there are no more callers. Signed-off-by: Jeff Layton Signed-off-by: Al Viro --- include/linux/fs.h | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'include') diff --git a/include/linux/fs.h b/include/linux/fs.h index 8ef2fc9f1f08..b44b4ca82164 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2228,8 +2228,7 @@ extern void __init vfs_caches_init(unsigned long); extern struct kmem_cache *names_cachep; -#define __getname_gfp(gfp) kmem_cache_alloc(names_cachep, (gfp)) -#define __getname() __getname_gfp(GFP_KERNEL) +#define __getname() kmem_cache_alloc(names_cachep, GFP_KERNEL) #define __putname(name) kmem_cache_free(names_cachep, (void *)(name)) #ifndef CONFIG_AUDITSYSCALL #define putname(name) __putname(name) -- cgit v1.2.3-59-g8ed1b