path: root/fs
diff options
authorJesper Juhl <jj@chaosbits.net>2012-04-12 22:47:52 +0200
committerDavid Sterba <dsterba@suse.cz>2012-04-18 19:22:20 +0200
commit4735fb282830c0966b301dabcccf4753fa6604bb (patch)
tree1749491d41f888c29dbad6de37fe3fbe81a38fc3 /fs
parentcdc6a3952558f00b1bc3b6401e1cf98797632fe2 (diff)
Btrfs: Make free_ipath() deal gracefully with NULL pointers
Make free_ipath() behave like most other freeing functions in the kernel and gracefully do nothing when passed a NULL pointer. Besides this making the bahaviour consistent with functions such as kfree(), vfree(), btrfs_free_path() etc etc, it also fixes a real NULL deref issue in fs/btrfs/ioctl.c::btrfs_ioctl_ino_to_path(). In that function we have this code: ... ipath = init_ipath(size, root, path); if (IS_ERR(ipath)) { ret = PTR_ERR(ipath); ipath = NULL; goto out; } ... out: btrfs_free_path(path); free_ipath(ipath); ... If we ever take the true branch of that 'if' statement we'll end up passing a NULL pointer to free_ipath() which will subsequently dereference it and we'll go "Boom" :-( This patch will avoid that. Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Diffstat (limited to 'fs')
1 files changed, 2 insertions, 0 deletions
diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c
index f4e90748940a..b332ff04c5ee 100644
--- a/fs/btrfs/backref.c
+++ b/fs/btrfs/backref.c
@@ -1414,6 +1414,8 @@ struct inode_fs_paths *init_ipath(s32 total_bytes, struct btrfs_root *fs_root,
void free_ipath(struct inode_fs_paths *ipath)
+ if (!ipath)
+ return;