On Tue, 4 Jan 2011 13:20:38 -0600 Shirish Pargaonkar <shirishpargaonkar@xxxxxxxxx> wrote: > On Tue, Jan 4, 2011 at 1:11 PM, Jeff Layton <jlayton@xxxxxxxxxx> wrote: > > On Mon, 6 Dec 2010 14:56:46 -0600 > > shirishpargaonkar@xxxxxxxxx wrote: > > > >> From: Shirish Pargaonkar <shirishpargaonkar@xxxxxxxxx> > >> > >> > >> If a DACL has entries for ACEs for SID Everyone and Authenticated Users, > >> factor in mask in respective entries during calculation of permissions > >> for all three, user, group, and other. > >> > >> http://technet.microsoft.com/en-us/library/bb463216.aspx > >> > >> > >> Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@xxxxxxxxx> > >> --- > >> fs/cifs/cifsacl.c | 13 +++++++++++-- > >> 1 files changed, 11 insertions(+), 2 deletions(-) > >> > >> diff --git a/fs/cifs/cifsacl.c b/fs/cifs/cifsacl.c > >> index c6ebea0..a520091 100644 > >> --- a/fs/cifs/cifsacl.c > >> +++ b/fs/cifs/cifsacl.c > >> @@ -43,9 +43,12 @@ static struct cifs_wksid wksidarr[NUM_WK_SIDS] = { > >> ; > >> > >> > >> -/* security id for everyone */ > >> +/* security id for everyone/world system group */ > >> static const struct cifs_sid sid_everyone = { > >> 1, 1, {0, 0, 0, 0, 0, 1}, {0} }; > >> +/* security id for Authenticated Users system group */ > >> +static const struct cifs_sid sid_authusers = { > >> + 1, 1, {0, 0, 0, 0, 0, 5}, {11} }; > >> /* group users */ > >> static const struct cifs_sid sid_user = {1, 2 , {0, 0, 0, 0, 0, 5}, {} }; > >> > >> @@ -367,7 +370,7 @@ static void parse_dacl(struct cifs_acl *pdacl, char *end_of_acl, > >> if (num_aces > 0) { > >> umode_t user_mask = S_IRWXU; > >> umode_t group_mask = S_IRWXG; > >> - umode_t other_mask = S_IRWXO; > >> + umode_t other_mask = S_IRWXU | S_IRWXG | S_IRWXO; > >> > >> ppace = kmalloc(num_aces * sizeof(struct cifs_ace *), > >> GFP_KERNEL); > >> @@ -392,6 +395,12 @@ static void parse_dacl(struct cifs_acl *pdacl, char *end_of_acl, > >> ppace[i]->type, > >> &fattr->cf_mode, > >> &other_mask); > >> + if (compare_sids(&(ppace[i]->sid), &sid_authusers)) > >> + access_flags_to_mode(ppace[i]->access_req, > >> + ppace[i]->type, > >> + &fattr->cf_mode, > >> + &other_mask); > >> + > >> > >> /* memcpy((void *)(&(cifscred->aces[i])), > >> (void *)ppace[i], > > > > This looks like a harmless change... > > > > Reviewed-by: Jeff Layton <jlayton@xxxxxxxxxx> > > > > Jeff, Thanks. > > > I have real doubts however about the owner/group parts of the cifsacl > > scheme. It sets the user and group mode bits without setting the user > > and group owners to meaningful values. So, those permissions have no > > basis in reality. > > With the sid to uid and gid mapping code using winbind in the works, > would that address these concerns? > Yes, that would help some. That would give you the ability to present permissions that have some basis in reality. You'll still have to figure out what to do when you get a SID that can't be mapped for some reason. The real solution is to get rid of client-side permissions enforcement altogether. The server is the only place that they can be reliably enforced. -- Jeff Layton <jlayton@xxxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe linux-cifs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
