Commit cf4ef780 authored by Stanislav Goriainov's avatar Stanislav Goriainov Committed by Miklos Szeredi
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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: 0a2d0d3f ("ovl: Check redirect on index as well")
Signed-off-by: default avatarStanislav Goriainov <goriainov@ispras.ru>
Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
parent af4dcb6d

fs/overlayfs/namei.c

+5 −0
Original line number Diff line number Diff line
@@ -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);