From 626ac545c12e5f9bffe93086d1d03d26c99987ea Mon Sep 17 00:00:00 2001 From: "Serge E. Hallyn" Date: Tue, 17 Jul 2007 15:28:17 -0400 Subject: user namespace: fix copy_user_ns return value When a CONFIG_USER_NS=n and a user tries to unshare some namespace other than the user namespace, the dummy copy_user_ns returns NULL rather than the old_ns. This value then gets assigned to task->nsproxy->user_ns, so that a subsequent setuid, which uses task->nsproxy->user_ns, causes a NULL pointer deref. Fix this by returning old_ns. Signed-off-by: Serge E. Hallyn Signed-off-by: Linus Torvalds --- include/linux/user_namespace.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/user_namespace.h') diff --git a/include/linux/user_namespace.h b/include/linux/user_namespace.h index bb320573bb9e..1101b0ce878f 100644 --- a/include/linux/user_namespace.h +++ b/include/linux/user_namespace.h @@ -49,7 +49,7 @@ static inline struct user_namespace *copy_user_ns(int flags, if (flags & CLONE_NEWUSER) return ERR_PTR(-EINVAL); - return NULL; + return old_ns; } static inline void put_user_ns(struct user_namespace *ns) -- cgit v1.2.3 From 735de2230f09741077a645a913de0a04b10208bf Mon Sep 17 00:00:00 2001 From: Pavel Emelyanov Date: Tue, 18 Sep 2007 22:46:44 -0700 Subject: Convert uid hash to hlist Surprisingly, but (spotted by Alexey Dobriyan) the uid hash still uses list_heads, thus occupying twice as much place as it could. Convert it to hlist_heads. Signed-off-by: Pavel Emelyanov Signed-off-by: Alexey Dobriyan Acked-by: Serge Hallyn Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/user_namespace.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/user_namespace.h') diff --git a/include/linux/user_namespace.h b/include/linux/user_namespace.h index 1101b0ce878f..b5f41d4c2eec 100644 --- a/include/linux/user_namespace.h +++ b/include/linux/user_namespace.h @@ -11,7 +11,7 @@ struct user_namespace { struct kref kref; - struct list_head uidhash_table[UIDHASH_SZ]; + struct hlist_head uidhash_table[UIDHASH_SZ]; struct user_struct *root_user; }; -- cgit v1.2.3