Hi list,
Here's the second patch from my coccicheck run. Originally it flagged
the fact that the opened file in psql's process_file() wasn't being
closed in the ON_ERROR_STOP path, but there seem to be two more
unintended behaviors here.
(1) In the error path, the value of pset.inputfile wasn't being
properly restored. The caller does free(fname) on line 786, so
psql.inputfile would point to unallocated memory.
(2) The more significant issue is that stdin *was closed in the
success return path. So when you run a script with two "\i -" lines,
the first "\q" would close stdin and the next one would fail with:
psql:-:0: could not read from input file: Bad file descriptor
In fact, this means that stdin was being accessed after being
fclose()d, which is undefined behavior per ANSI C, though it seems to
work just fine on Linux.
The new behavior requires the same amount of "\q"s as the number of
executions of '-' because stdin is never closed.
Regards,
Marti
From 43b7595fdcc69cc9db0d066a53f53c5e71c965aa Mon Sep 17 00:00:00 2001
From: Marti Raudsepp <ma...@juffo.org>
Date: Wed, 20 Oct 2010 23:44:36 +0300
Subject: [PATCH] psql: Don't close stdin, don't leak file descriptor with ON_ERROR_STOP
Changes three things:
1. Don't close stdin when returning success if input was stdin
2. Don't leak file descriptor when exiting due to ON_ERROR_STOP
3. pset.inputfile wasn't being restored with ON_ERROR_STOP, yet the
memory was freed by the caller
(1) changes the behavior of "\q" on stdin. Previously multiple
inclusions of stdin would be terminated with a single quit, now a
separate quit is needed for each invocation. Previous behavior also
accessed stdin after it was fclose()d, which is undefined behavior per
ANSI C.
(2) and (3) should have no practical impact, because the process would
quit immediately afterwards anyway.
---
src/bin/psql/command.c | 15 ++++++++++++---
1 files changed, 12 insertions(+), 3 deletions(-)
diff --git a/src/bin/psql/command.c b/src/bin/psql/command.c
index e6d703a..45a145c 100644
--- a/src/bin/psql/command.c
+++ b/src/bin/psql/command.c
@@ -1987,7 +1987,10 @@ process_file(char *filename, bool single_txn)
if ((res = PSQLexec("BEGIN", false)) == NULL)
{
if (pset.on_error_stop)
- return EXIT_USER;
+ {
+ result = EXIT_USER;
+ goto error;
+ }
}
else
PQclear(res);
@@ -2000,13 +2003,19 @@ process_file(char *filename, bool single_txn)
if ((res = PSQLexec("COMMIT", false)) == NULL)
{
if (pset.on_error_stop)
- return EXIT_USER;
+ {
+ result = EXIT_USER;
+ goto error;
+ }
}
else
PQclear(res);
}
- fclose(fd);
+error:
+ if(fd != stdin)
+ fclose(fd);
+
pset.inputfile = oldfilename;
return result;
}
--
1.7.3.1
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