Previously, in auth_unix_gid, group lists were stored in an array of
hard-coded length 100, and in the situation that the group lists for a
particular call were too large, the array was swapped with a dynamically
allocated/freed buffer. For environments where users are commonly in
a large number of groups, this isn't an ideal approach.
Instead, make the group list static scoped to the function, and
use malloc/realloc to grow it on an as-needed basis.
Signed-off-by: Sean Finney <sean.finney@xxxxxxxxxxxxxxxx>
---
utils/mountd/cache.c | 29 ++++++++++++++++++++---------
1 files changed, 20 insertions(+), 9 deletions(-)
diff --git a/utils/mountd/cache.c b/utils/mountd/cache.c
index 9bbbfb3..7deb050 100644
--- a/utils/mountd/cache.c
+++ b/utils/mountd/cache.c
@@ -37,6 +37,7 @@
#include "blkid/blkid.h"
#endif
+#define INITIAL_MANAGED_GROUPS 100
enum nfsd_fsid {
FSID_DEV = 0,
@@ -127,11 +128,21 @@ void auth_unix_gid(FILE *f)
*/
int uid;
struct passwd *pw;
- gid_t glist[100], *groups = glist;
- int ngroups = 100;
+ static gid_t *groups = NULL;
+ static int groups_len = 0;
+ gid_t *more_groups;
+ int ngroups = 0;
int rv, i;
char *cp;
+ if (groups_len == 0) {
+ groups = malloc(sizeof(gid_t)*INITIAL_MANAGED_GROUPS);
+ if (!groups)
+ return;
+
+ groups_len = ngroups = INITIAL_MANAGED_GROUPS;
+ }
+
if (readline(fileno(f), &lbuf, &lbuflen) != 1)
return;
@@ -144,13 +155,16 @@ void auth_unix_gid(FILE *f)
rv = -1;
else {
rv = getgrouplist(pw->pw_name, pw->pw_gid, groups, &ngroups);
- if (rv == -1 && ngroups >= 100) {
- groups = malloc(sizeof(gid_t)*ngroups);
- if (!groups)
+ if (rv == -1 && ngroups >= groups_len) {
+ more_groups = realloc(groups, sizeof(gid_t)*ngroups);
+ if (!more_groups)
rv = -1;
- else
+ else {
+ groups = more_groups;
+ groups_len = ngroups;
rv = getgrouplist(pw->pw_name, pw->pw_gid,
groups, &ngroups);
+ }
}
}
qword_printint(f, uid);
@@ -162,9 +176,6 @@ void auth_unix_gid(FILE *f)
} else
qword_printint(f, 0);
qword_eol(f);
-
- if (groups != glist)
- free(groups);
}
#if USE_BLKID
--
1.7.4.1
--
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