local-CVE-2024-33600-nscd

commit 69c58d5ef9f584ea198bd00f7964d364d0e6b921
Author: Florian Weimer <fweimer@redhat.com>
Date:   Thu Apr 25 15:00:45 2024 +0200

    CVE-2024-33599: nscd: Stack-based buffer overflow in netgroup cache (bug 31677)

    Using alloca matches what other caches do.  The request length is
    bounded by MAXKEYLEN.

    Reviewed-by: Carlos O'Donell <carlos@redhat.com>
    (cherry picked from commit 87801a8fd06db1d654eea3e4f7626ff476a9bdaa)

commit 304ce5fe466c4762b21b36c26926a4657b59b53e
Author: Florian Weimer <fweimer@redhat.com>
Date:   Thu Apr 25 15:01:07 2024 +0200

    CVE-2024-33600: nscd: Do not send missing not-found response in addgetnetgrentX (bug 31678)

    If we failed to add a not-found response to the cache, the dataset
    point can be null, resulting in a null pointer dereference.

    Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
    (cherry picked from commit 7835b00dbce53c3c87bbbb1754a95fb5e58187aa)

Gbp-Pq: Topic any
Gbp-Pq: Name local-CVE-2024-33600-nscd.patch

diff --git a/nscd/netgroupcache.c b/nscd/netgroupcache.c
index a833ef039ef1704f623e70d592f6ee3570bb536c..e936b698c4ca1c3d77d96e1d2cd8e35e4be8da16 100644 (file)
--- a/nscd/netgroupcache.c
+++ b/nscd/netgroupcache.c
@@ -148,7 +148,7 @@ addgetnetgrentX (struct database_dyn *db, int fd, request_header *req,
       /* No such service.  */
       cacheable = do_notfound (db, fd, req, key, &dataset, &total, &timeout,
                               &key_copy);
-      goto writeout;
+      goto maybe_cache_add;
     }
 
   memset (&data, '\0', sizeof (data));
@@ -349,7 +349,7 @@ addgetnetgrentX (struct database_dyn *db, int fd, request_header *req,
     {
       cacheable = do_notfound (db, fd, req, key, &dataset, &total, &timeout,
                               &key_copy);
-      goto writeout;
+      goto maybe_cache_add;
     }
 
   total = buffilled;
@@ -411,14 +411,12 @@ addgetnetgrentX (struct database_dyn *db, int fd, request_header *req,
   }
 
   if (he == NULL && fd != -1)
-    {
-      /* We write the dataset before inserting it to the database
-        since while inserting this thread might block and so would
-        unnecessarily let the receiver wait.  */
-    writeout:
+    /* We write the dataset before inserting it to the database since
+       while inserting this thread might block and so would
+       unnecessarily let the receiver wait.  */
       writeall (fd, &dataset->resp, dataset->head.recsize);
-    }
 
+ maybe_cache_add:
   if (cacheable)
     {
       /* If necessary, we also propagate the data to disk.  */
@@ -514,14 +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;
 
@@ -569,7 +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