NFS: Fix access to suid/sgid executables
nfs_open_permission_mask() should only check MAY_EXEC for files that
are opened with __FMODE_EXEC.
Also fix NFSv4 access-in-open path in a similar way -- openflags must be
used because fmode will not always have FMODE_EXEC set.
This patch fixes https://bugzilla.kernel.org/show_bug.cgi?id=49101
Signed-off-by: Weston Andros Adamson <dros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 5d864fb..cf747ef 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -1626,7 +1626,8 @@
static int nfs4_opendata_access(struct rpc_cred *cred,
struct nfs4_opendata *opendata,
- struct nfs4_state *state, fmode_t fmode)
+ struct nfs4_state *state, fmode_t fmode,
+ int openflags)
{
struct nfs_access_entry cache;
u32 mask;
@@ -1638,11 +1639,14 @@
mask = 0;
/* don't check MAY_WRITE - a newly created file may not have
- * write mode bits, but POSIX allows the creating process to write */
- if (fmode & FMODE_READ)
- mask |= MAY_READ;
- if (fmode & FMODE_EXEC)
- mask |= MAY_EXEC;
+ * write mode bits, but POSIX allows the creating process to write.
+ * use openflags to check for exec, because fmode won't
+ * always have FMODE_EXEC set when file open for exec. */
+ if (openflags & __FMODE_EXEC) {
+ /* ONLY check for exec rights */
+ mask = MAY_EXEC;
+ } else if (fmode & FMODE_READ)
+ mask = MAY_READ;
cache.cred = cred;
cache.jiffies = jiffies;
@@ -1896,7 +1900,7 @@
if (server->caps & NFS_CAP_POSIX_LOCK)
set_bit(NFS_STATE_POSIX_LOCKS, &state->flags);
- status = nfs4_opendata_access(cred, opendata, state, fmode);
+ status = nfs4_opendata_access(cred, opendata, state, fmode, flags);
if (status != 0)
goto err_opendata_put;