From c455cdb30d212b6488d3e9f2f663fcc1f6ad267c Mon Sep 17 00:00:00 2001
From: Karel Zak
Date: Mon, 10 Dec 2018 14:26:04 +0100
Subject: choom: fix negative adjust score usage

It's really bad idea to use uint64_t (ul_path_write_u64(()) when write
signed number.

Addresses: https://github.com/karelzak/util-linux/issues/723
Signed-off-by: Karel Zak <kzak@redhat.com>
---
 include/path.h    |  1 +
 lib/path.c        | 22 ++++++++++++++++++++++
 sys-utils/choom.c |  2 +-
 3 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/include/path.h b/include/path.h
index b34aa366e..8dadef1d0 100644
--- a/include/path.h
+++ b/include/path.h
@@ -110,6 +110,7 @@ int ul_path_write_string(struct path_cxt *pc, const char *str, const char *path)
 int ul_path_writef_string(struct path_cxt *pc, const char *str, const char *path, ...)
 				__attribute__ ((__format__ (__printf__, 3, 4)));
 
+int ul_path_write_s64(struct path_cxt *pc, int64_t num, const char *path);
 int ul_path_write_u64(struct path_cxt *pc, uint64_t num, const char *path);
 int ul_path_writef_u64(struct path_cxt *pc, uint64_t num, const char *path, ...)
 				__attribute__ ((__format__ (__printf__, 3, 4)));
diff --git a/lib/path.c b/lib/path.c
index d36fe41e8..9dfdc94f8 100644
--- a/lib/path.c
+++ b/lib/path.c
@@ -850,6 +850,28 @@ int ul_path_writef_string(struct path_cxt *pc, const char *str, const char *path
 	return ul_path_write_string(pc, str, p);
 }
 
+int ul_path_write_s64(struct path_cxt *pc, int64_t num, const char *path)
+{
+	char buf[sizeof(stringify_value(LLONG_MAX))];
+	int rc, errsv;
+	int fd, len;
+
+	fd = ul_path_open(pc, O_WRONLY|O_CLOEXEC, path);
+	if (fd < 0)
+		return -errno;
+
+	len = snprintf(buf, sizeof(buf), "%" PRId64, num);
+	if (len < 0 || (size_t) len >= sizeof(buf))
+		rc = len < 0 ? -errno : -E2BIG;
+	else
+		rc = write_all(fd, buf, len);
+
+	errsv = errno;
+	close(fd);
+	errno = errsv;
+	return rc;
+}
+
 int ul_path_write_u64(struct path_cxt *pc, uint64_t num, const char *path)
 {
 	char buf[sizeof(stringify_value(ULLONG_MAX))];
diff --git a/sys-utils/choom.c b/sys-utils/choom.c
index 6895aef43..eff95b6bf 100644
--- a/sys-utils/choom.c
+++ b/sys-utils/choom.c
@@ -74,7 +74,7 @@ static int get_score_adj(struct path_cxt *pc)
 
 static int set_score_adj(struct path_cxt *pc, int adj)
 {
-	return ul_path_write_u64(pc, adj, "oom_score_adj");
+	return ul_path_write_s64(pc, adj, "oom_score_adj");
 }
 
 int main(int argc, char **argv)
-- 
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