diff options
| author | Stanislav Goriainov | 2022-08-31 11:06:58 +0300 |
|---|---|---|
| committer | Miklos Szeredi | 2022-12-08 10:49:46 +0100 |
| commit | cf4ef7801a8c880902a07712ba7ff61d8e954f85 (patch) | |
| tree | 4e3ca6541e4b7cd47d6d60ed2acc8d2f7128311b | |
| parent | af4dcb6d78b2b05a0431dfd3f67713bba8dc0900 (diff) | |
ovl: Add comment on upperredirect reassignment
If memory for uperredirect was allocated with kstrdup() in upperdir != NULL
and d.redirect != NULL path, it may seem that it can be lost when
upperredirect is reassigned later, but it's not possible.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Fixes: 0a2d0d3f2f291 ("ovl: Check redirect on index as well")
Signed-off-by: Stanislav Goriainov <goriainov@ispras.ru>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
| -rw-r--r-- | fs/overlayfs/namei.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/fs/overlayfs/namei.c b/fs/overlayfs/namei.c index 0ce1f9b3a046..46753134533a 100644 --- a/fs/overlayfs/namei.c +++ b/fs/overlayfs/namei.c @@ -1086,6 +1086,11 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, .mnt = ovl_upper_mnt(ofs), }; + /* + * It's safe to assign upperredirect here: the previous + * assignment of happens only if upperdentry is non-NULL, and + * this one only if upperdentry is NULL. + */ upperredirect = ovl_get_redirect_xattr(ofs, &upperpath, 0); if (IS_ERR(upperredirect)) { err = PTR_ERR(upperredirect); |