systemd/SOURCES/0802-core-be-more-careful-w...

69 lines
2.3 KiB
Diff

From d6ffd324cc933efec946a3ffbed6fccfe7077203 Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Mon, 26 Nov 2018 21:07:48 +0100
Subject: [PATCH] core: be more careful when inheriting stdout fds to stderr
We need to compare the fd name/file name if we inherit an fd from stdout
to stderr. Let's do that.
Fixes: #10875
(cherry picked from commit 41fc585a7a3b8ae857cad5fdad1bc70cdacfa8e5)
Related: #2093479
---
src/core/execute.c | 27 +++++++++++++++++++++++++--
1 file changed, 25 insertions(+), 2 deletions(-)
diff --git a/src/core/execute.c b/src/core/execute.c
index 9cbb678ac4..b1d8dceb32 100644
--- a/src/core/execute.c
+++ b/src/core/execute.c
@@ -545,6 +545,30 @@ static int setup_input(
}
}
+static bool can_inherit_stderr_from_stdout(
+ const ExecContext *context,
+ ExecOutput o,
+ ExecOutput e) {
+
+ assert(context);
+
+ /* Returns true, if given the specified STDERR and STDOUT output we can directly dup() the stdout fd to the
+ * stderr fd */
+
+ if (e == EXEC_OUTPUT_INHERIT)
+ return true;
+ if (e != o)
+ return false;
+
+ if (e == EXEC_OUTPUT_NAMED_FD)
+ return streq_ptr(context->stdio_fdname[STDOUT_FILENO], context->stdio_fdname[STDERR_FILENO]);
+
+ if (IN_SET(e, EXEC_OUTPUT_FILE, EXEC_OUTPUT_FILE_APPEND))
+ return streq_ptr(context->stdio_file[STDOUT_FILENO], context->stdio_file[STDERR_FILENO]);
+
+ return true;
+}
+
static int setup_output(
const Unit *unit,
const ExecContext *context,
@@ -603,7 +627,7 @@ static int setup_output(
return fileno;
/* Duplicate from stdout if possible */
- if ((e == o && e != EXEC_OUTPUT_NAMED_FD) || e == EXEC_OUTPUT_INHERIT)
+ if (can_inherit_stderr_from_stdout(context, o, e))
return dup2(STDOUT_FILENO, fileno) < 0 ? -errno : fileno;
o = e;
@@ -694,7 +718,6 @@ static int setup_output(
flags |= O_APPEND;
fd = acquire_path(context->stdio_file[fileno], flags, 0666 & ~context->umask);
-
if (fd < 0)
return fd;