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authorDJ Delorie <dj@redhat.com>2021-02-25 16:08:21 -0500
committerSiddhesh Poyarekar <siddhesh@sourceware.org>2021-03-08 15:42:28 +0530
commit4352eb4e5d3e8e53497250b1929db731143abe16 (patch)
tree6d06a1739b84e486a7ddd32d5122ccee9cef93f8
parente9db77683e10c589529f452710868c3bde2c6d3f (diff)
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nscd: Fix double free in netgroupcache [BZ #27462]
In commit 745664bd798ec8fd50438605948eea594179fba1 a use-after-free
was fixed, but this led to an occasional double-free.  This patch
tracks the "live" allocation better.

Tested manually by a third party.

Related: RHBZ 1927877

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
(cherry picked from commit dca565886b5e8bd7966e15f0ca42ee5cff686673)
-rw-r--r--nscd/netgroupcache.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/nscd/netgroupcache.c b/nscd/netgroupcache.c
index 87059fb280..c89629aec8 100644
--- a/nscd/netgroupcache.c
+++ b/nscd/netgroupcache.c
@@ -248,7 +248,7 @@ addgetnetgrentX (struct database_dyn *db, int fd, request_header *req,
 					     : NULL);
 				    ndomain = (ndomain ? newbuf + ndomaindiff
 					       : NULL);
-				    buffer = newbuf;
+				    *tofreep = buffer = newbuf;
 				  }
 
 				nhost = memcpy (buffer + bufused,
@@ -319,7 +319,7 @@ addgetnetgrentX (struct database_dyn *db, int fd, request_header *req,
 		    else if (status == NSS_STATUS_TRYAGAIN && e == ERANGE)
 		      {
 			buflen *= 2;
-			buffer = xrealloc (buffer, buflen);
+			*tofreep = buffer = xrealloc (buffer, buflen);
 		      }
 		    else if (status == NSS_STATUS_RETURN
 			     || status == NSS_STATUS_NOTFOUND