From 03010366b6fb61aac0998f234478cc745ff97b0c Mon Sep 17 00:00:00 2001 From: Stephen Frost Date: Mon, 15 Jul 2013 10:42:27 -0400 Subject: [PATCH] Correct off-by-one when reading from pipe In pg_basebackup.c:reached_end_position(), we're reading from an internal pipe with our own background process but we're possibly reading more bytes than will actually fit into our buffer due to an off-by-one error. As we're reading from an internal pipe there's no real risk here, but it's good form to not depend on such convenient arrangements. Bug spotted by the Coverity scanner. Back-patch to 9.2 where this showed up. --- src/bin/pg_basebackup/pg_basebackup.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/src/bin/pg_basebackup/pg_basebackup.c b/src/bin/pg_basebackup/pg_basebackup.c index 56657a42c40..a1e12a8aaa3 100644 --- a/src/bin/pg_basebackup/pg_basebackup.c +++ b/src/bin/pg_basebackup/pg_basebackup.c @@ -174,7 +174,7 @@ reached_end_position(XLogRecPtr segendpos, uint32 timeline, lo; MemSet(xlogend, 0, sizeof(xlogend)); - r = read(bgpipe[0], xlogend, sizeof(xlogend)); + r = read(bgpipe[0], xlogend, sizeof(xlogend)-1); if (r < 0) { fprintf(stderr, _("%s: could not read from ready pipe: %s\n"),