From 3bd858ab1c451725c07a805dcb315215dc85b86e Mon Sep 17 00:00:00 2001 From: Satyam Sharma Date: Tue, 17 Jul 2007 15:00:08 +0530 Subject: Introduce is_owner_or_cap() to wrap CAP_FOWNER use with fsuid check Introduce is_owner_or_cap() macro in fs.h, and convert over relevant users to it. This is done because we want to avoid bugs in the future where we check for only effective fsuid of the current task against a file's owning uid, without simultaneously checking for CAP_FOWNER as well, thus violating its semantics. [ XFS uses special macros and structures, and in general looked ... untouchable, so we leave it alone -- but it has been looked over. ] The (current->fsuid != inode->i_uid) check in generic_permission() and exec_permission_lite() is left alone, because those operations are covered by CAP_DAC_OVERRIDE and CAP_DAC_READ_SEARCH. Similarly operations falling under the purview of CAP_CHOWN and CAP_LEASE are also left alone. Signed-off-by: Satyam Sharma Cc: Al Viro Acked-by: Serge E. Hallyn Signed-off-by: Linus Torvalds --- include/linux/fs.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'include') diff --git a/include/linux/fs.h b/include/linux/fs.h index 58ce336d4a6b..98205f680476 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -284,6 +284,7 @@ extern int dir_notify_enable; #include #include #include +#include #include #include @@ -990,6 +991,9 @@ enum { #define put_fs_excl() atomic_dec(¤t->fs_excl) #define has_fs_excl() atomic_read(¤t->fs_excl) +#define is_owner_or_cap(inode) \ + ((current->fsuid == (inode)->i_uid) || capable(CAP_FOWNER)) + /* not quite ready to be deprecated, but... */ extern void lock_super(struct super_block *); extern void unlock_super(struct super_block *); -- cgit v1.2.1