check delete permission on source before doing any work

[unix-history] / usr / src / sys / ufs / ffs / ffs_vnops.c

diff --git a/usr/src/sys/ufs/ffs/ffs_vnops.c b/usr/src/sys/ufs/ffs/ffs_vnops.c
index e484b12..9565334 100644 (file)
--- a/usr/src/sys/ufs/ffs/ffs_vnops.c
+++ b/usr/src/sys/ufs/ffs/ffs_vnops.c
@@ -1,4 +1,4 @@
-/*     ffs_vnops.c     4.51    83/02/20        */
+/*     ffs_vnops.c     4.52    83/03/21        */

 
 #include "../h/param.h"
 #include "../h/systm.h"
 
 #include "../h/param.h"
 #include "../h/systm.h"


@@ -914,7 +914,7 @@ rename()
        int error = 0;
 
        uap = (struct a *)u.u_ap;
        int error = 0;
 
        uap = (struct a *)u.u_ap;

-       ip = namei(uchar, LOOKUP | LOCKPARENT, 0);
+       ip = namei(uchar, DELETE | LOCKPARENT, 0);

        if (ip == NULL)
                return;
        dp = u.u_pdir;
        if (ip == NULL)
                return;
        dp = u.u_pdir;


@@ -924,20 +924,23 @@ rename()
 
                d = &u.u_dent;
                /*
 
                d = &u.u_dent;
                /*

-                * Avoid "." and ".." for obvious reasons.
+                * Avoid ".", "..", and aliases of "." for obvious reasons.

                 */
                 */

-               if (d->d_name[0] == '.') {
-                       if (d->d_namlen == 1 ||
-                           (d->d_namlen == 2 && d->d_name[1] == '.')) {
+               if ((d->d_namlen == 1 && d->d_name[0] == '.') ||
+                   (d->d_namlen == 2 && bcmp(d->d_name, "..", 2) == 0) ||
+                   (dp == ip)) {
+                       iput(dp);
+                       if (dp == ip)
+                               irele(ip);
+                       else

                                iput(ip);
                                iput(ip);

-                               u.u_error = EINVAL;
-                               return;
-                       }
+                       u.u_error = EINVAL;
+                       return;

                }
                oldparent = dp->i_number;
                doingdirectory++;
        }
                }
                oldparent = dp->i_number;
                doingdirectory++;
        }

-       irele(dp);
+       iput(dp);

 
        /*
         * 1) Bump link count while we're moving stuff
 
        /*
         * 1) Bump link count while we're moving stuff


@@ -961,6 +964,13 @@ rename()
                goto out;
        }
        dp = u.u_pdir;
                goto out;
        }
        dp = u.u_pdir;

+       /*
+        * If ".." must be changed (ie the directory gets a new
+        * parent) then the user must have write permission.
+        */
+       parentdifferent = oldparent != dp->i_number;
+       if (parentdifferent && access(ip, IWRITE))
+               goto bad;

        /*
         * 2) If target doesn't exist, link the target
         *    to the source and unlink the source. 
        /*
         * 2) If target doesn't exist, link the target
         *    to the source and unlink the source. 


@@ -968,7 +978,6 @@ rename()
         *    entry to reference the source inode and
         *    expunge the original entry's existence.
         */
         *    entry to reference the source inode and
         *    expunge the original entry's existence.
         */

-       parentdifferent = oldparent != dp->i_number;

        if (xp == NULL) {
                if (dp->i_dev != ip->i_dev) {
                        error = EXDEV;
        if (xp == NULL) {
                if (dp->i_dev != ip->i_dev) {
                        error = EXDEV;