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| author | Siddhesh Poyarekar <siddhesh@redhat.com> | 2014-03-27 19:48:15 +0530 |
|---|---|---|
| committer | Siddhesh Poyarekar <siddhesh@redhat.com> | 2014-03-27 19:48:15 +0530 |
| commit | ea7d8b95e2fcb81f68b04ed7787a3dbda023991a (patch) | |
| tree | 20e3018b10da00729cd8a8feec1e2265b173c321 /nscd | |
| parent | df5b85da90915ce6208ad737807e3d8f2a8fce87 (diff) | |
| download | glibc-ea7d8b95e2fcb81f68b04ed7787a3dbda023991a.tar.gz | |
Avoid overlapping addresses to stpcpy calls in nscd (BZ #16760)
Calls to stpcpy from nscd netgroups code will have overlapping source
and destination when all three values in the returned triplet are
non-NULL and in the expected (host,user,domain) order. This is seen
in valgrind as:
==3181== Source and destination overlap in stpcpy(0x19973b48, 0x19973b48)
==3181== at 0x4C2F30A: stpcpy (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==3181== by 0x12567A: addgetnetgrentX (string3.h:111)
==3181== by 0x12722D: addgetnetgrent (netgroupcache.c:665)
==3181== by 0x11114C: nscd_run_worker (connections.c:1338)
==3181== by 0x4E3C102: start_thread (pthread_create.c:309)
==3181== by 0x59B81AC: clone (clone.S:111)
==3181==
Fix this by using memmove instead of stpcpy.
Diffstat (limited to 'nscd')
| -rw-r--r-- | nscd/netgroupcache.c | 16 |
1 files changed, 10 insertions, 6 deletions
diff --git a/nscd/netgroupcache.c b/nscd/netgroupcache.c index 5d15aa49f4..820d8234b4 100644 --- a/nscd/netgroupcache.c +++ b/nscd/netgroupcache.c @@ -216,6 +216,10 @@ addgetnetgrentX (struct database_dyn *db, int fd, request_header *req, const char *nuser = data.val.triple.user; const char *ndomain = data.val.triple.domain; + size_t hostlen = strlen (nhost ?: "") + 1; + size_t userlen = strlen (nuser ?: "") + 1; + size_t domainlen = strlen (ndomain ?: "") + 1; + if (nhost == NULL || nuser == NULL || ndomain == NULL || nhost > nuser || nuser > ndomain) { @@ -233,9 +237,6 @@ addgetnetgrentX (struct database_dyn *db, int fd, request_header *req, : last + strlen (last) + 1 - buffer); /* We have to make temporary copies. */ - size_t hostlen = strlen (nhost ?: "") + 1; - size_t userlen = strlen (nuser ?: "") + 1; - size_t domainlen = strlen (ndomain ?: "") + 1; size_t needed = hostlen + userlen + domainlen; if (buflen - req->key_len - bufused < needed) @@ -269,9 +270,12 @@ addgetnetgrentX (struct database_dyn *db, int fd, request_header *req, } char *wp = buffer + buffilled; - wp = stpcpy (wp, nhost) + 1; - wp = stpcpy (wp, nuser) + 1; - wp = stpcpy (wp, ndomain) + 1; + wp = memmove (wp, nhost ?: "", hostlen); + wp += hostlen; + wp = memmove (wp, nuser ?: "", userlen); + wp += userlen; + wp = memmove (wp, ndomain ?: "", domainlen); + wp += domainlen; buffilled = wp - buffer; ++nentries; } |