Message ID | 4EEA5926.9090500@canonical.com |
---|---|
State | New |
Headers | show |
On Thu, Dec 15, 2011 at 02:31:34PM -0600, Chris J Arges wrote: > SRU Justification > > Impact: > > NFSv4 mount point does not allow binary files to run when permissions > are set to 111. > > Fix: > > Upstream commit a043226bc140a2c1dde162246d68a67e5043e6b2. > Applies with minor conflicts (include file is in a different directory). > > Testcase: > Mount a directory using nfsv4. Inside that directory place a binary with > ---x--x--x permissions. Try to execute the binary. Without this patch it > will not execute. > > Notes: > This patch fixes this issue, but requires support from the nfs client as > well. The Lucid version of the client works as expected. > > Thanks, > --chris j arges > From 88c0bdee31a467bb55a3f812b6ae63dae4330a79 Mon Sep 17 00:00:00 2001 > From: "J. Bruce Fields" <bfields@redhat.com> > Date: Thu, 25 Aug 2011 10:48:39 -0400 > Subject: [PATCH] nfsd4: permit read opens of executable-only files > > A client that wants to execute a file must be able to read it. Read > opens over nfs are therefore implicitly allowed for executable files > even when those files are not readable. > > NFSv2/v3 get this right by using a passed-in NFSD_MAY_OWNER_OVERRIDE on > read requests, but NFSv4 has gotten this wrong ever since > dc730e173785e29b297aa605786c94adaffe2544 "nfsd4: fix owner-override on > open", when we realized that the file owner shouldn't override > permissions on non-reclaim NFSv4 opens. > > So we can't use NFSD_MAY_OWNER_OVERRIDE to tell nfsd_permission to allow > reads of executable files. > > So, do the same thing we do whenever we encounter another weird NFS > permission nit: define yet another NFSD_MAY_* flag. > > The industry's future standardization on 128-bit processors will be > motivated primarily by the need for integers with enough bits for all > the NFSD_MAY_* flags. > > Reported-by: Leonardo Borda <leonardoborda@gmail.com> > Cc: stable@kernel.org > Signed-off-by: J. Bruce Fields <bfields@redhat.com> > (cherry picked from commit a043226bc140a2c1dde162246d68a67e5043e6b2) > > BugLink: http://bugs.launchpad.net/bugs/833300 You forgot to add your Sign-off, no big problem though: Acked-by: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com> > > Conflicts: > > fs/nfsd/vfs.h > --- > fs/nfsd/nfs4proc.c | 2 ++ > fs/nfsd/vfs.c | 3 ++- > include/linux/nfsd/nfsd.h | 1 + > 3 files changed, 5 insertions(+), 1 deletions(-) > > diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c > index 01d83a5..f865116 100644 > --- a/fs/nfsd/nfs4proc.c > +++ b/fs/nfsd/nfs4proc.c > @@ -166,6 +166,8 @@ do_open_permission(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfs > !(open->op_share_access & NFS4_SHARE_ACCESS_WRITE)) > return nfserr_inval; > > + accmode |= NFSD_MAY_READ_IF_EXEC; > + > if (open->op_share_access & NFS4_SHARE_ACCESS_READ) > accmode |= NFSD_MAY_READ; > if (open->op_share_access & NFS4_SHARE_ACCESS_WRITE) > diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c > index 2e09588..494350b 100644 > --- a/fs/nfsd/vfs.c > +++ b/fs/nfsd/vfs.c > @@ -2118,7 +2118,8 @@ nfsd_permission(struct svc_rqst *rqstp, struct svc_export *exp, > > /* Allow read access to binaries even when mode 111 */ > if (err == -EACCES && S_ISREG(inode->i_mode) && > - acc == (NFSD_MAY_READ | NFSD_MAY_OWNER_OVERRIDE)) > + (acc == (NFSD_MAY_READ | NFSD_MAY_OWNER_OVERRIDE) || > + acc == (NFSD_MAY_READ | NFSD_MAY_READ_IF_EXEC))) > err = inode_permission(inode, MAY_EXEC); > if (err) > goto nfsd_out; > diff --git a/include/linux/nfsd/nfsd.h b/include/linux/nfsd/nfsd.h > index 510ffdd..3436ec6 100644 > --- a/include/linux/nfsd/nfsd.h > +++ b/include/linux/nfsd/nfsd.h > @@ -38,6 +38,7 @@ > #define NFSD_MAY_OWNER_OVERRIDE 64 > #define NFSD_MAY_LOCAL_ACCESS 128 /* IRIX doing local access check on device special file*/ > #define NFSD_MAY_BYPASS_GSS_ON_ROOT 256 > +#define NFSD_MAY_READ_IF_EXEC 2048 > > #define NFSD_MAY_CREATE (NFSD_MAY_EXEC|NFSD_MAY_WRITE) > #define NFSD_MAY_REMOVE (NFSD_MAY_EXEC|NFSD_MAY_WRITE|NFSD_MAY_TRUNC) > -- > 1.7.5.4 > > -- > kernel-team mailing list > kernel-team@lists.ubuntu.com > https://lists.ubuntu.com/mailman/listinfo/kernel-team
On 12/15/2011 01:31 PM, Chris J Arges wrote: > SRU Justification > > Impact: > > NFSv4 mount point does not allow binary files to run when permissions > are set to 111. > > Fix: > > Upstream commit a043226bc140a2c1dde162246d68a67e5043e6b2. > Applies with minor conflicts (include file is in a different directory). > > Testcase: > Mount a directory using nfsv4. Inside that directory place a binary with > ---x--x--x permissions. Try to execute the binary. Without this patch it > will not execute. > > Notes: > This patch fixes this issue, but requires support from the nfs client as > well. The Lucid version of the client works as expected. > > Thanks, > --chris j arges > If we're gonna provide fixes for Lucid and Natty, then we'd better do so for Maverick.
From 88c0bdee31a467bb55a3f812b6ae63dae4330a79 Mon Sep 17 00:00:00 2001 From: "J. Bruce Fields" <bfields@redhat.com> Date: Thu, 25 Aug 2011 10:48:39 -0400 Subject: [PATCH] nfsd4: permit read opens of executable-only files A client that wants to execute a file must be able to read it. Read opens over nfs are therefore implicitly allowed for executable files even when those files are not readable. NFSv2/v3 get this right by using a passed-in NFSD_MAY_OWNER_OVERRIDE on read requests, but NFSv4 has gotten this wrong ever since dc730e173785e29b297aa605786c94adaffe2544 "nfsd4: fix owner-override on open", when we realized that the file owner shouldn't override permissions on non-reclaim NFSv4 opens. So we can't use NFSD_MAY_OWNER_OVERRIDE to tell nfsd_permission to allow reads of executable files. So, do the same thing we do whenever we encounter another weird NFS permission nit: define yet another NFSD_MAY_* flag. The industry's future standardization on 128-bit processors will be motivated primarily by the need for integers with enough bits for all the NFSD_MAY_* flags. Reported-by: Leonardo Borda <leonardoborda@gmail.com> Cc: stable@kernel.org Signed-off-by: J. Bruce Fields <bfields@redhat.com> (cherry picked from commit a043226bc140a2c1dde162246d68a67e5043e6b2) BugLink: http://bugs.launchpad.net/bugs/833300 Conflicts: fs/nfsd/vfs.h --- fs/nfsd/nfs4proc.c | 2 ++ fs/nfsd/vfs.c | 3 ++- include/linux/nfsd/nfsd.h | 1 + 3 files changed, 5 insertions(+), 1 deletions(-) diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c index 01d83a5..f865116 100644 --- a/fs/nfsd/nfs4proc.c +++ b/fs/nfsd/nfs4proc.c @@ -166,6 +166,8 @@ do_open_permission(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfs !(open->op_share_access & NFS4_SHARE_ACCESS_WRITE)) return nfserr_inval; + accmode |= NFSD_MAY_READ_IF_EXEC; + if (open->op_share_access & NFS4_SHARE_ACCESS_READ) accmode |= NFSD_MAY_READ; if (open->op_share_access & NFS4_SHARE_ACCESS_WRITE) diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c index 2e09588..494350b 100644 --- a/fs/nfsd/vfs.c +++ b/fs/nfsd/vfs.c @@ -2118,7 +2118,8 @@ nfsd_permission(struct svc_rqst *rqstp, struct svc_export *exp, /* Allow read access to binaries even when mode 111 */ if (err == -EACCES && S_ISREG(inode->i_mode) && - acc == (NFSD_MAY_READ | NFSD_MAY_OWNER_OVERRIDE)) + (acc == (NFSD_MAY_READ | NFSD_MAY_OWNER_OVERRIDE) || + acc == (NFSD_MAY_READ | NFSD_MAY_READ_IF_EXEC))) err = inode_permission(inode, MAY_EXEC); if (err) goto nfsd_out; diff --git a/include/linux/nfsd/nfsd.h b/include/linux/nfsd/nfsd.h index 510ffdd..3436ec6 100644 --- a/include/linux/nfsd/nfsd.h +++ b/include/linux/nfsd/nfsd.h @@ -38,6 +38,7 @@ #define NFSD_MAY_OWNER_OVERRIDE 64 #define NFSD_MAY_LOCAL_ACCESS 128 /* IRIX doing local access check on device special file*/ #define NFSD_MAY_BYPASS_GSS_ON_ROOT 256 +#define NFSD_MAY_READ_IF_EXEC 2048 #define NFSD_MAY_CREATE (NFSD_MAY_EXEC|NFSD_MAY_WRITE) #define NFSD_MAY_REMOVE (NFSD_MAY_EXEC|NFSD_MAY_WRITE|NFSD_MAY_TRUNC) -- 1.7.5.4