path: root/init/do_mounts.c
diff options
authorJeff Layton <jlayton@redhat.com>2012-10-10 15:25:26 -0400
committerAl Viro <viro@zeniv.linux.org.uk>2012-10-12 00:32:03 -0400
commita608ca21f58ee44df5a71ba140e98498f3ebc2cd (patch)
tree4ba6f5d5414ba9b579c8e41eb30c21a709537922 /init/do_mounts.c
parent4fa6b5ecbf092c6ee752ece8a55d71f663d23254 (diff)
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 <jlayton@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'init/do_mounts.c')
1 files changed, 4 insertions, 3 deletions
diff --git a/init/do_mounts.c b/init/do_mounts.c
index d3f0aeed2d39..f8a66424360d 100644
--- a/init/do_mounts.c
+++ b/init/do_mounts.c
@@ -353,8 +353,9 @@ static int __init do_mount_root(char *name, char *fs, int flags, void *data)
void __init mount_block_root(char *name, int flags)
- char *fs_names = __getname_gfp(GFP_KERNEL
+ struct page *page = alloc_page(GFP_KERNEL |
+ char *fs_names = page_address(page);
char *p;
@@ -406,7 +407,7 @@ retry:
panic("VFS: Unable to mount root fs on %s", b);
- putname(fs_names);
+ put_page(page);

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