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authorJeff Layton <jlayton@redhat.com>2009-05-24 18:45:15 -0400
committerSteve French <sfrench@us.ibm.com>2009-06-06 21:03:27 +0000
commit4ae1507f6d266d0cc3dd36e474d83aad70fec9e4 (patch)
treeae41fd204f772ecc8f9adc2e727a9eb01999784e
parent50b64e3b77d569c217a48e078cd565dbd6462ad0 (diff)
downloadop-kernel-dev-4ae1507f6d266d0cc3dd36e474d83aad70fec9e4.zip
op-kernel-dev-4ae1507f6d266d0cc3dd36e474d83aad70fec9e4.tar.gz
cifs: make overriding of ownership conditional on new mount options
We have a bit of a problem with the uid= option. The basic issue is that it means too many things and has too many side-effects. It's possible to allow an unprivileged user to mount a filesystem if the user owns the mountpoint, /bin/mount is setuid root, and the mount is set up in /etc/fstab with the "user" option. When doing this though, /bin/mount automatically adds the "uid=" and "gid=" options to the share. This is fortunate since the correct uid= option is needed in order to tell the upcall what user's credcache to use when generating the SPNEGO blob. On a mount without unix extensions this is fine -- you generally will want the files to be owned by the "owner" of the mount. The problem comes in on a mount with unix extensions. With those enabled, the uid/gid options cause the ownership of files to be overriden even though the server is sending along the ownership info. This means that it's not possible to have a mount by an unprivileged user that shows the server's file ownership info. The result is also inode permissions that have no reflection at all on the server. You simply cannot separate ownership from the mode in this fashion. This behavior also makes MultiuserMount option less usable. Once you pass in the uid= option for a mount, then you can't use unix ownership info and allow someone to share the mount. While I'm not thrilled with it, the only solution I can see is to stop making uid=/gid= force the overriding of ownership on mounts, and to add new mount options that turn this behavior on. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Steve French <sfrench@us.ibm.com>
-rw-r--r--fs/cifs/connect.c8
1 files changed, 4 insertions, 4 deletions
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 74b5a87..10151f8 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -1096,17 +1096,17 @@ cifs_parse_mount_options(char *options, const char *devname,
return 1;
}
} else if (strnicmp(data, "uid", 3) == 0) {
- if (value && *value) {
+ if (value && *value)
vol->linux_uid =
simple_strtoul(value, &value, 0);
+ } else if (strnicmp(data, "forceuid", 8) == 0) {
vol->override_uid = 1;
- }
} else if (strnicmp(data, "gid", 3) == 0) {
- if (value && *value) {
+ if (value && *value)
vol->linux_gid =
simple_strtoul(value, &value, 0);
+ } else if (strnicmp(data, "forcegid", 8) == 0) {
vol->override_gid = 1;
- }
} else if (strnicmp(data, "file_mode", 4) == 0) {
if (value && *value) {
vol->file_mode =
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