seccomp: Fix ioctl number for SECCOMP_IOCTL_NOTIF_ID_VALID

[ Upstream commit 47e33c05f9f07cac3de833e531bcac9ae052c7ca ]

When SECCOMP_IOCTL_NOTIF_ID_VALID was first introduced it had the wrong
direction flag set. While this isn't a big deal as nothing currently
enforces these bits in the kernel, it should be defined correctly. Fix
the define and provide support for the old command until it is no longer
needed for backward compatibility.

Fixes: 6a21cc50f0c7 ("seccomp: add a return code to trap to userspace")
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/include/uapi/linux/seccomp.h b/include/uapi/linux/seccomp.h
index 90734aa5aa3630de48eab60759dc93e7f308ed70..b5f901af79f0b411610b78206d8499567d3f6300 100644 (file)
--- a/include/uapi/linux/seccomp.h
+++ b/include/uapi/linux/seccomp.h
@@ -93,5 +93,6 @@ struct seccomp_notif_resp {
 #define SECCOMP_IOCTL_NOTIF_RECV       SECCOMP_IOWR(0, struct seccomp_notif)
 #define SECCOMP_IOCTL_NOTIF_SEND       SECCOMP_IOWR(1, \
                                                struct seccomp_notif_resp)
-#define SECCOMP_IOCTL_NOTIF_ID_VALID   SECCOMP_IOR(2, __u64)
+#define SECCOMP_IOCTL_NOTIF_ID_VALID   SECCOMP_IOW(2, __u64)
+
 #endif /* _UAPI_LINUX_SECCOMP_H */

diff --git a/kernel/seccomp.c b/kernel/seccomp.c
index 2c697ce7be21fa19b47b56e5cacd95e3315964be..e0fd9723565390cbdce67bc326d4ca7d5b1add8d 100644 (file)
--- a/kernel/seccomp.c
+++ b/kernel/seccomp.c
@@ -42,6 +42,14 @@
 #include <linux/uaccess.h>
 #include <linux/anon_inodes.h>
 
+/*
+ * When SECCOMP_IOCTL_NOTIF_ID_VALID was first introduced, it had the
+ * wrong direction flag in the ioctl number. This is the broken one,
+ * which the kernel needs to keep supporting until all userspaces stop
+ * using the wrong command number.
+ */
+#define SECCOMP_IOCTL_NOTIF_ID_VALID_WRONG_DIR SECCOMP_IOR(2, __u64)
+
 enum notify_state {
        SECCOMP_NOTIFY_INIT,
        SECCOMP_NOTIFY_SENT,
@@ -1168,6 +1176,7 @@ static long seccomp_notify_ioctl(struct file *file, unsigned int cmd,
                return seccomp_notify_recv(filter, buf);
        case SECCOMP_IOCTL_NOTIF_SEND:
                return seccomp_notify_send(filter, buf);
+       case SECCOMP_IOCTL_NOTIF_ID_VALID_WRONG_DIR:
        case SECCOMP_IOCTL_NOTIF_ID_VALID:
                return seccomp_notify_id_valid(filter, buf);
        default:

diff --git a/tools/testing/selftests/seccomp/seccomp_bpf.c b/tools/testing/selftests/seccomp/seccomp_bpf.c
index 96bbda4f10fc644047974e351299944407e9da74..19c7351eeb74b1bfd7b9d13411f6de07ce76f9bb 100644 (file)
--- a/tools/testing/selftests/seccomp/seccomp_bpf.c
+++ b/tools/testing/selftests/seccomp/seccomp_bpf.c
@@ -177,7 +177,7 @@ struct seccomp_metadata {
 #define SECCOMP_IOCTL_NOTIF_RECV       SECCOMP_IOWR(0, struct seccomp_notif)
 #define SECCOMP_IOCTL_NOTIF_SEND       SECCOMP_IOWR(1, \
                                                struct seccomp_notif_resp)
-#define SECCOMP_IOCTL_NOTIF_ID_VALID   SECCOMP_IOR(2, __u64)
+#define SECCOMP_IOCTL_NOTIF_ID_VALID   SECCOMP_IOW(2, __u64)
 
 struct seccomp_notif {
        __u64 id;