Kees Cook <keescook@xxxxxxxxxxxx> writes: > On Thu, Aug 2, 2012 at 9:26 PM, James Morris <jmorris@xxxxxxxxx> wrote: >> On Wed, 25 Jul 2012, Kees Cook wrote: >> >>> This adds symlink and hardlink restrictions to the Linux VFS. >> >> Is Al happy with this now? > > Looks like it; thanks for checking. It's in mainline now: > http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=commitdiff;h=800179c9b8a1e796e441674776d11cd4c05d61d7 So there was one trivial little issue with your patch. You were directly comparing kuids instead of using uid_eq. This only practically matters when user namespaces are enabled which is currently impossible in 3.6-rc1 :( I have added the following fixup patch to my for-next branch of user-namespace.git From: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx> Date: Fri, 3 Aug 2012 09:38:08 -0700 Subject: [PATCH] userns: Fix link restrictions to use uid_eq Signed-off-by: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx> --- fs/namei.c | 6 +++--- 1 files changed, 3 insertions(+), 3 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index 1b46439..05480a6 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -678,7 +678,7 @@ static inline int may_follow_link(struct path *link, struct nameidata *nd) /* Allowed if owner and follower match. */ inode = link->dentry->d_inode; - if (current_cred()->fsuid == inode->i_uid) + if (uid_eq(current_cred()->fsuid, inode->i_uid)) return 0; /* Allowed if parent directory not sticky and world-writable. */ @@ -687,7 +687,7 @@ static inline int may_follow_link(struct path *link, struct nameidata *nd) return 0; /* Allowed if parent directory and link owner match. */ - if (parent->i_uid == inode->i_uid) + if (uid_eq(parent->i_uid, inode->i_uid)) return 0; path_put_conditional(link, nd); @@ -757,7 +757,7 @@ static int may_linkat(struct path *link) /* Source inode owner (or CAP_FOWNER) can hardlink all they like, * otherwise, it must be a safe source. */ - if (cred->fsuid == inode->i_uid || safe_hardlink_source(inode) || + if (uid_eq(cred->fsuid, inode->i_uid) || safe_hardlink_source(inode) || capable(CAP_FOWNER)) return 0; -- 1.7.5.4 -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
