From: Harald Hoyer <harald@redhat.com>
Date: Tue, 19 Jun 2012 14:53:29 +0000 (-0400)
Subject: nfsdcld: Before clearing the capability bounding set, check if we have the cap
X-Git-Tag: debian/1%1.2.8-1~11^2^2~108
X-Git-Url: https://git.decadent.org.uk/gitweb/?a=commitdiff_plain;h=d18b89cd7352783580f3d3dde26f8617e36459b9;p=nfs-utils.git

nfsdcld: Before clearing the capability bounding set, check if we have the cap

From: Harald Hoyer <harald@redhat.com>

PR_CAPBSET_DROP can return EINVAL, if an older kernel does support
some capabilities, which are defined by CAP_LAST_CAP, which results in
a failure of the service.

For example kernel 3.4 errors on CAP_EPOLLWAKEUP, which was newly
introduced in 3.5.

So, for future capabilities, we clear until we get an EINVAL for
PR_CAPBSET_READ.

Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve Dickson <steved@redhat.com>
---

diff --git a/support/nsm/file.c b/support/nsm/file.c
index 5476446..4711c2c 100644
--- a/support/nsm/file.c
+++ b/support/nsm/file.c
@@ -386,7 +386,7 @@ prune_bounding_set(void)
 	}
 
 	/* prune the bounding set to nothing */
-	for (i = 0; i <= CAP_LAST_CAP; ++i) {
+	for (i = 0; prctl(PR_CAPBSET_READ, i, 0, 0, 0) >=0 ; ++i) {
 		ret = prctl(PR_CAPBSET_DROP, i, 0, 0, 0);
 		if (ret) {
 			xlog(L_ERROR, "Unable to prune capability %lu from "
diff --git a/utils/nfsdcld/nfsdcld.c b/utils/nfsdcld/nfsdcld.c
index e7af4e3..473d069 100644
--- a/utils/nfsdcld/nfsdcld.c
+++ b/utils/nfsdcld/nfsdcld.c
@@ -102,8 +102,8 @@ cld_set_caps(void)
 	}
 
 	/* prune the bounding set to nothing */
-	for (i = 0; i <= CAP_LAST_CAP; ++i) {
-		ret = prctl(PR_CAPBSET_DROP, i);
+	for (i = 0; prctl(PR_CAPBSET_READ, i, 0, 0, 0) >= 0 ; ++i) {
+		ret = prctl(PR_CAPBSET_DROP, i, 0, 0, 0);
 		if (ret) {
 			xlog(L_ERROR, "Unable to prune capability %lu from "
 				      "bounding set: %m", i);