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authorCsaba Henk <csaba@redhat.com>2017-07-05 17:48:37 +0200
committerJeff Darcy <jeff@pl.atyp.us>2017-07-06 18:26:08 +0000
commite14ea3f5c37475e12a3b7fb7bd3165b0a4e77c51 (patch)
tree7ef467ec7fa1761379a101ada475f504c479a42f /xlators
parentfc73ae5f81ef5926e3dc2311db116250d0f2a321 (diff)
groups: don't allocate auxiliary gid list on stack
When glusterfs wants to retrieve the list of auxiliary gids of a user, it typically allocates a sufficiently big gid_t array on stack and calls getgrouplist(3) with it. However, "sufficiently big" means to be of maximum supported gid list size, which in GlusterFS is GF_MAX_AUX_GROUPS = 64k. That means a 64k * sizeof(gid_t) = 256k allocation, which is big enough to overflow the stack in certain cases. A further observation is that stack allocation of the gid list brings no gain, as in all cases the content of the gid list eventually gets copied over to a heap allocated buffer. So we add a convenience wrapper of getgrouplist to libglusterfs called gf_getgrouplist which calls getgrouplist with a sufficiently big heap allocated buffer (it takes care of the allocation too). We are porting all the getgrouplist invocations to gf_getgrouplist and thus eliminate the huge stack allocation. BUG: 1464327 Change-Id: Icea76d0d74dcf2f87d26cb299acc771ca3b32d2b Signed-off-by: Csaba Henk <csaba@redhat.com> Reviewed-on: https://review.gluster.org/17706 Smoke: Gluster Build System <jenkins@build.gluster.org> Reviewed-by: Niels de Vos <ndevos@redhat.com> Reviewed-by: Amar Tumballi <amarts@redhat.com> CentOS-regression: Gluster Build System <jenkins@build.gluster.org>
Diffstat (limited to 'xlators')
-rw-r--r--xlators/mount/fuse/src/fuse-helpers.c20
-rw-r--r--xlators/nfs/server/src/nfs-fops.c36
-rw-r--r--xlators/protocol/server/src/server-helpers.c23
3 files changed, 27 insertions, 52 deletions
diff --git a/xlators/mount/fuse/src/fuse-helpers.c b/xlators/mount/fuse/src/fuse-helpers.c
index b65e6ebfc7b..3fc6b16c41f 100644
--- a/xlators/mount/fuse/src/fuse-helpers.c
+++ b/xlators/mount/fuse/src/fuse-helpers.c
@@ -20,7 +20,6 @@
#include <sys/sysctl.h>
#endif
#include <pwd.h>
-#include <grp.h>
#include "fuse-bridge.h"
@@ -158,8 +157,8 @@ frame_fill_groups (call_frame_t *frame)
char *saveptr = NULL;
char *endptr = NULL;
int ret = 0;
- int ngroups = FUSE_MAX_AUX_GROUPS;
- gid_t mygroups[GF_MAX_AUX_GROUPS];
+ int ngroups = 0;
+ gid_t *mygroups = NULL;
if (priv->resolve_gids) {
struct passwd pwent;
@@ -173,23 +172,16 @@ frame_fill_groups (call_frame_t *frame)
return;
}
- ngroups = GF_MAX_AUX_GROUPS;
- if (getgrouplist (result->pw_name, frame->root->gid, mygroups,
- &ngroups) == -1) {
+ ngroups = gf_getgrouplist (result->pw_name, frame->root->gid,
+ &mygroups);
+ if (ngroups == -1) {
gf_log (this->name, GF_LOG_ERROR, "could not map %s to "
"group list (ngroups %d, max %d)",
result->pw_name, ngroups, GF_MAX_AUX_GROUPS);
return;
}
- if (call_stack_alloc_groups (frame->root, ngroups) != 0)
- goto out;
-
- /* Copy data to the frame. */
- for (idx = 0; idx < ngroups; ++idx) {
- frame->root->groups[idx] = mygroups[idx];
- }
- frame->root->ngrps = ngroups;
+ call_stack_set_groups (frame->root, ngroups, mygroups);
} else {
ret = snprintf (filename, sizeof filename, "/proc/%d/status",
frame->root->pid);
diff --git a/xlators/nfs/server/src/nfs-fops.c b/xlators/nfs/server/src/nfs-fops.c
index f6361f02161..28b1781f4b1 100644
--- a/xlators/nfs/server/src/nfs-fops.c
+++ b/xlators/nfs/server/src/nfs-fops.c
@@ -8,7 +8,6 @@
cases as published by the Free Software Foundation.
*/
-#include <grp.h>
#include <pwd.h>
#include "dict.h"
@@ -34,12 +33,7 @@ nfs_fix_groups (xlator_t *this, call_stack_t *root)
struct passwd mypw;
char mystrs[1024];
struct passwd *result;
-#ifdef GF_DARWIN_HOST_OS
- /* BSD/DARWIN does not correctly uses gid_t in getgrouplist */
- int mygroups[GF_MAX_AUX_GROUPS];
-#else
- gid_t mygroups[GF_MAX_AUX_GROUPS];
-#endif
+ gid_t *mygroups;
int ngroups;
int i;
int max_groups;
@@ -88,25 +82,13 @@ nfs_fix_groups (xlator_t *this, call_stack_t *root)
gf_msg_trace (this->name, 0, "mapped %u => %s",
root->uid, result->pw_name);
- ngroups = GF_MAX_AUX_GROUPS;
- if (getgrouplist(result->pw_name,root->gid,mygroups,&ngroups) == -1) {
+ ngroups = gf_getgrouplist (result->pw_name, root->gid, &mygroups);
+ if (ngroups == -1) {
gf_msg (this->name, GF_LOG_ERROR, 0, NFS_MSG_MAP_GRP_LIST_FAIL,
"could not map %s to group list", result->pw_name);
return;
}
- /* Add the group data to the cache. */
- gl.gl_list = GF_CALLOC(ngroups, sizeof(gid_t), gf_nfs_mt_aux_gids);
- if (gl.gl_list) {
- /* It's not fatal if the alloc failed. */
- gl.gl_id = root->uid;
- gl.gl_uid = 0;
- gl.gl_gid = 0;
- gl.gl_count = ngroups;
- memcpy(gl.gl_list, mygroups, sizeof(gid_t) * ngroups);
- if (gid_cache_add(&priv->gid_cache, &gl) != 1)
- GF_FREE(gl.gl_list);
- }
/* RPC enforces the GF_AUTH_GLUSTERFS_MAX_GROUPS limit */
if (ngroups > max_groups) {
@@ -115,16 +97,24 @@ nfs_fix_groups (xlator_t *this, call_stack_t *root)
"too many groups, reducing %d -> %d",
ngroups, max_groups);
- ngroups = max_groups;
}
/* Copy data to the frame. */
- for (i = 0; i < ngroups; ++i) {
+ for (i = 0; i < ngroups && i < max_groups; ++i) {
gf_msg_trace (this->name, 0, "%s is in group %u",
result->pw_name, mygroups[i]);
root->groups[i] = mygroups[i];
}
root->ngrps = ngroups;
+
+ /* Add the group data to the cache. */
+ gl.gl_list = mygroups;
+ gl.gl_id = root->uid;
+ gl.gl_uid = 0;
+ gl.gl_gid = 0;
+ gl.gl_count = ngroups;
+ if (gid_cache_add(&priv->gid_cache, &gl) != 1)
+ GF_FREE(mygroups);
}
struct nfs_fop_local *
diff --git a/xlators/protocol/server/src/server-helpers.c b/xlators/protocol/server/src/server-helpers.c
index 37f7bca47f0..09e0012d70a 100644
--- a/xlators/protocol/server/src/server-helpers.c
+++ b/xlators/protocol/server/src/server-helpers.c
@@ -19,7 +19,6 @@
#include <fnmatch.h>
#include <pwd.h>
-#include <grp.h>
#include "compound-fop-utils.h"
/* based on nfs_fix_aux_groups() */
@@ -30,10 +29,10 @@ gid_resolve (server_conf_t *conf, call_stack_t *root)
struct passwd mypw;
char mystrs[1024];
struct passwd *result;
- gid_t mygroups[GF_MAX_AUX_GROUPS];
+ gid_t *mygroups;
gid_list_t gl;
const gid_list_t *agl;
- int ngroups, i;
+ int ngroups;
agl = gid_cache_lookup (&conf->gid_cache, root->uid, 0, 0);
if (agl) {
@@ -58,9 +57,8 @@ gid_resolve (server_conf_t *conf, call_stack_t *root)
gf_msg_trace ("gid-cache", 0, "mapped %u => %s", root->uid,
result->pw_name);
- ngroups = GF_MAX_AUX_GROUPS;
- ret = getgrouplist (result->pw_name, root->gid, mygroups, &ngroups);
- if (ret == -1) {
+ ngroups = gf_getgrouplist (result->pw_name, root->gid, &mygroups);
+ if (ngroups == -1) {
gf_msg ("gid-cache", GF_LOG_ERROR, 0, PS_MSG_MAPPING_ERROR,
"could not map %s to group list (%d gids)",
result->pw_name, root->ngrps);
@@ -84,8 +82,10 @@ fill_groups:
if (gl.gl_list)
memcpy (gl.gl_list, mygroups,
sizeof(gid_t) * root->ngrps);
- else
+ else {
+ GF_FREE (mygroups);
return -1;
+ }
}
if (root->ngrps == 0) {
@@ -93,14 +93,7 @@ fill_groups:
goto out;
}
- if (call_stack_alloc_groups (root, root->ngrps) != 0) {
- ret = -1;
- goto out;
- }
-
- /* finally fill the groups from the */
- for (i = 0; i < root->ngrps; ++i)
- root->groups[i] = gl.gl_list[i];
+ call_stack_set_groups (root, root->ngrps, mygroups);
out:
if (agl) {