On Monday January 6, okir@suse.de wrote:
> On Mon, Jan 06, 2003 at 07:33:20PM +0000, Dave Jones wrote:
> > I'm going through the old 2.4 changelogs looking for bits that
> > have been missed out, the little one liners have been going
> > direct to Linus/maintainer, but here's the first one I'm
> > unsure of..
> >
> > Any reason this is missing in 2.5 ?
>
> I think I sent it to the NFS mailing list and forgot about it
> afterwards.
>
> The problem this patch tries to address is that the current code allows
> diskless clients to chmod device files, even when the directory is
> exported read-only.
This has been on my list of things to follow up in 2.5 .... for quite
a while. Thanks for the prompting.
I'll commit to getting an appropriate patch to Linus, probably
something like the following.
Thanks,
NeilBrown
----------- Diffstat output ------------
./fs/nfsd/nfsproc.c | 4 ++--
./fs/nfsd/vfs.c | 8 ++++----
./include/linux/nfsd/nfsd.h | 3 ++-
3 files changed, 8 insertions(+), 7 deletions(-)
diff ./fs/nfsd/nfsproc.c~current~ ./fs/nfsd/nfsproc.c
--- ./fs/nfsd/nfsproc.c~current~ 2003-01-08 11:20:22.000000000 +1100
+++ ./fs/nfsd/nfsproc.c 2003-01-08 11:20:41.000000000 +1100
@@ -250,11 +250,11 @@ nfsd_proc_create(struct svc_rqst *rqstp,
/* this is probably a permission check..
* at least IRIX implements perm checking on
* echo thing > device-special-file-or-pipe
- * by does a CREATE with type==0
+ * by doing a CREATE with type==0
*/
nfserr = nfsd_permission(newfhp->fh_export,
newfhp->fh_dentry,
- MAY_WRITE);
+ MAY_WRITE|MAY_LOCAL_ACCESS);
if (nfserr && nfserr != nfserr_rofs)
goto out_unlock;
}
diff ./fs/nfsd/vfs.c~current~ ./fs/nfsd/vfs.c
--- ./fs/nfsd/vfs.c~current~ 2003-01-08 11:20:51.000000000 +1100
+++ ./fs/nfsd/vfs.c 2003-01-08 11:23:00.000000000 +1100
@@ -1515,11 +1515,11 @@ nfsd_permission(struct svc_export *exp,
inode->i_uid, inode->i_gid, current->fsuid, current->fsgid);
#endif
- /* only care about readonly exports for files and
- * directories. links don't have meaningful write access,
- * and all else is local to the client
+ /* Normally we reject any write/sattr etc access on a read-only file
+ * system. But if it is IRIX doing check on write-access for a
+ * device special file, we ignore rofs.
*/
- if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode))
+ if (!(acc & MAY_LOCAL_ACCESS))
if (acc & (MAY_WRITE | MAY_SATTR | MAY_TRUNC)) {
if (EX_RDONLY(exp) || IS_RDONLY(inode))
return nfserr_rofs;
diff ./include/linux/nfsd/nfsd.h~current~ ./include/linux/nfsd/nfsd.h
--- ./include/linux/nfsd/nfsd.h~current~ 2003-01-08 11:18:25.000000000 +1100
+++ ./include/linux/nfsd/nfsd.h 2003-01-08 11:19:51.000000000 +1100
@@ -38,7 +38,8 @@
#define MAY_TRUNC 16
#define MAY_LOCK 32
#define MAY_OWNER_OVERRIDE 64
-#if (MAY_SATTR | MAY_TRUNC | MAY_LOCK | MAX_OWNER_OVERRIDE) & (MAY_READ | MAY_WRITE | MAY_EXEC | MAY_OWNER_OVERRIDE)
+#define MAY_LOCAL_ACCESS 128 /* IRIX doing local access check on device special file*/
+#if (MAY_SATTR | MAY_TRUNC | MAY_LOCK | MAX_OWNER_OVERRIDE | MAY_LOCAL_ACCESS) & (MAY_READ | MAY_WRITE | MAY_EXEC | MAY_OWNER_OVERRIDE)
# error "please use a different value for MAY_SATTR or MAY_TRUNC or MAY_LOCK or MAY_OWNER_OVERRIDE."
#endif
#define MAY_CREATE (MAY_EXEC|MAY_WRITE)
-
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This archive was generated by hypermail 2b29 : Tue Jan 07 2003 - 22:00:37 EST