92 lines
2.4 KiB
Diff
92 lines
2.4 KiB
Diff
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From: "Eric W. Biederman" <ebiederm@xmission.com>
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Date: Tue, 2 Dec 2014 13:56:30 -0600
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Subject: [PATCH] userns: Unbreak the unprivileged remount tests
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A security fix in caused the way the unprivileged remount tests were
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using user namespaces to break. Tweak the way user namespaces are
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being used so the test works again.
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Cc: stable@vger.kernel.org
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Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
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---
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.../selftests/mount/unprivileged-remount-test.c | 32 ++++++++++++++++------
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1 file changed, 24 insertions(+), 8 deletions(-)
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diff --git a/tools/testing/selftests/mount/unprivileged-remount-test.c b/tools/testing/selftests/mount/unprivileged-remount-test.c
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index 9669d375625a..517785052f1c 100644
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--- a/tools/testing/selftests/mount/unprivileged-remount-test.c
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+++ b/tools/testing/selftests/mount/unprivileged-remount-test.c
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@@ -53,17 +53,14 @@ static void die(char *fmt, ...)
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exit(EXIT_FAILURE);
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}
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-static void write_file(char *filename, char *fmt, ...)
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+static void vmaybe_write_file(bool enoent_ok, char *filename, char *fmt, va_list ap)
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{
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char buf[4096];
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int fd;
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ssize_t written;
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int buf_len;
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- va_list ap;
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- va_start(ap, fmt);
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buf_len = vsnprintf(buf, sizeof(buf), fmt, ap);
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- va_end(ap);
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if (buf_len < 0) {
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die("vsnprintf failed: %s\n",
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strerror(errno));
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@@ -74,6 +71,8 @@ static void write_file(char *filename, char *fmt, ...)
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fd = open(filename, O_WRONLY);
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if (fd < 0) {
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+ if ((errno == ENOENT) && enoent_ok)
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+ return;
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die("open of %s failed: %s\n",
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filename, strerror(errno));
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}
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@@ -92,6 +91,26 @@ static void write_file(char *filename, char *fmt, ...)
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}
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}
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+static void maybe_write_file(char *filename, char *fmt, ...)
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+{
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+ va_list ap;
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+
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+ va_start(ap, fmt);
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+ vmaybe_write_file(true, filename, fmt, ap);
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+ va_end(ap);
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+
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+}
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+
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+static void write_file(char *filename, char *fmt, ...)
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+{
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+ va_list ap;
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+
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+ va_start(ap, fmt);
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+ vmaybe_write_file(false, filename, fmt, ap);
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+ va_end(ap);
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+
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+}
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+
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static int read_mnt_flags(const char *path)
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{
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int ret;
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@@ -144,13 +163,10 @@ static void create_and_enter_userns(void)
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strerror(errno));
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}
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+ maybe_write_file("/proc/self/setgroups", "deny");
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write_file("/proc/self/uid_map", "0 %d 1", uid);
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write_file("/proc/self/gid_map", "0 %d 1", gid);
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- if (setgroups(0, NULL) != 0) {
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- die("setgroups failed: %s\n",
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- strerror(errno));
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- }
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if (setgid(0) != 0) {
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die ("setgid(0) failed %s\n",
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strerror(errno));
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--
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2.1.0
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