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authorEric W. Biederman <ebiederm@xmission.com>2014-12-02 20:56:30 +0100
committerEric W. Biederman <ebiederm@xmission.com>2014-12-12 01:07:07 +0100
commitdb86da7cb76f797a1a8b445166a15cb922c6ff85 (patch)
tree555f131be82199d97ed63118d8f00d3a768f5f96 /tools
parentuserns; Correct the comment in map_write (diff)
downloadlinux-db86da7cb76f797a1a8b445166a15cb922c6ff85.tar.xz
linux-db86da7cb76f797a1a8b445166a15cb922c6ff85.zip
userns: Unbreak the unprivileged remount tests
A security fix in caused the way the unprivileged remount tests were using user namespaces to break. Tweak the way user namespaces are being used so the test works again. Cc: stable@vger.kernel.org Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Diffstat (limited to 'tools')
-rw-r--r--tools/testing/selftests/mount/unprivileged-remount-test.c32
1 files changed, 24 insertions, 8 deletions
diff --git a/tools/testing/selftests/mount/unprivileged-remount-test.c b/tools/testing/selftests/mount/unprivileged-remount-test.c
index 9669d375625a..517785052f1c 100644
--- a/tools/testing/selftests/mount/unprivileged-remount-test.c
+++ b/tools/testing/selftests/mount/unprivileged-remount-test.c
@@ -53,17 +53,14 @@ static void die(char *fmt, ...)
exit(EXIT_FAILURE);
}
-static void write_file(char *filename, char *fmt, ...)
+static void vmaybe_write_file(bool enoent_ok, char *filename, char *fmt, va_list ap)
{
char buf[4096];
int fd;
ssize_t written;
int buf_len;
- va_list ap;
- va_start(ap, fmt);
buf_len = vsnprintf(buf, sizeof(buf), fmt, ap);
- va_end(ap);
if (buf_len < 0) {
die("vsnprintf failed: %s\n",
strerror(errno));
@@ -74,6 +71,8 @@ static void write_file(char *filename, char *fmt, ...)
fd = open(filename, O_WRONLY);
if (fd < 0) {
+ if ((errno == ENOENT) && enoent_ok)
+ return;
die("open of %s failed: %s\n",
filename, strerror(errno));
}
@@ -92,6 +91,26 @@ static void write_file(char *filename, char *fmt, ...)
}
}
+static void maybe_write_file(char *filename, char *fmt, ...)
+{
+ va_list ap;
+
+ va_start(ap, fmt);
+ vmaybe_write_file(true, filename, fmt, ap);
+ va_end(ap);
+
+}
+
+static void write_file(char *filename, char *fmt, ...)
+{
+ va_list ap;
+
+ va_start(ap, fmt);
+ vmaybe_write_file(false, filename, fmt, ap);
+ va_end(ap);
+
+}
+
static int read_mnt_flags(const char *path)
{
int ret;
@@ -144,13 +163,10 @@ static void create_and_enter_userns(void)
strerror(errno));
}
+ maybe_write_file("/proc/self/setgroups", "deny");
write_file("/proc/self/uid_map", "0 %d 1", uid);
write_file("/proc/self/gid_map", "0 %d 1", gid);
- if (setgroups(0, NULL) != 0) {
- die("setgroups failed: %s\n",
- strerror(errno));
- }
if (setgid(0) != 0) {
die ("setgid(0) failed %s\n",
strerror(errno));