54 lines
2.3 KiB
Diff
54 lines
2.3 KiB
Diff
commit b048a482f088e53144d26a61c390bed0210f49f2
|
|
Author: Florian Weimer <fweimer@redhat.com>
|
|
Date: Thu Apr 25 15:01:07 2024 +0200
|
|
|
|
CVE-2024-33600: nscd: Avoid null pointer crashes after notfound response (bug 31678)
|
|
|
|
The addgetnetgrentX call in addinnetgrX may have failed to produce
|
|
a result, so the result variable in addinnetgrX can be NULL.
|
|
Use db->negtimeout as the fallback value if there is no result data;
|
|
the timeout is also overwritten below.
|
|
|
|
Also avoid sending a second not-found response. (The client
|
|
disconnects after receiving the first response, so the data stream did
|
|
not go out of sync even without this fix.) It is still beneficial to
|
|
add the negative response to the mapping, so that the client can get
|
|
it from there in the future, instead of going through the socket.
|
|
|
|
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
|
|
|
|
diff --git a/nscd/netgroupcache.c b/nscd/netgroupcache.c
|
|
index a3e04b4c43e6acae..f656872ae8c3b888 100644
|
|
--- a/nscd/netgroupcache.c
|
|
+++ b/nscd/netgroupcache.c
|
|
@@ -512,14 +512,15 @@ addinnetgrX (struct database_dyn *db, int fd, request_header *req,
|
|
|
|
datahead_init_pos (&dataset->head, sizeof (*dataset) + req->key_len,
|
|
sizeof (innetgroup_response_header),
|
|
- he == NULL ? 0 : dh->nreloads + 1, result->head.ttl);
|
|
+ he == NULL ? 0 : dh->nreloads + 1,
|
|
+ result == NULL ? db->negtimeout : result->head.ttl);
|
|
/* Set the notfound status and timeout based on the result from
|
|
getnetgrent. */
|
|
- dataset->head.notfound = result->head.notfound;
|
|
+ dataset->head.notfound = result == NULL || result->head.notfound;
|
|
dataset->head.timeout = timeout;
|
|
|
|
dataset->resp.version = NSCD_VERSION;
|
|
- dataset->resp.found = result->resp.found;
|
|
+ dataset->resp.found = result != NULL && result->resp.found;
|
|
/* Until we find a matching entry the result is 0. */
|
|
dataset->resp.result = 0;
|
|
|
|
@@ -567,7 +568,9 @@ addinnetgrX (struct database_dyn *db, int fd, request_header *req,
|
|
goto out;
|
|
}
|
|
|
|
- if (he == NULL)
|
|
+ /* addgetnetgrentX may have already sent a notfound response. Do
|
|
+ not send another one. */
|
|
+ if (he == NULL && dataset->resp.found)
|
|
{
|
|
/* We write the dataset before inserting it to the database
|
|
since while inserting this thread might block and so would
|