commit 0e64123141f3854e695eb4924d82b52856691466
author Olivier Deprez <olivier.deprez@arm.com> Thu Sep 23 10:07:05 2021 +0200
committer Olivier Deprez <olivier.deprez@arm.com> Tue Oct 26 16:50:53 2021 +0100
tree 9f79e140db584f9b107f4e33373a0075983df1f4
parent 98854e9675dc7d951fa9c4e10d9c9d230c54bde6

Update Linux to v5.4.148

Sourced from [1]

[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.4.148.tar.gz

Change-Id: Ib3d26c5ba9b022e2e03533005c4fed4d7c30b61b
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>

kernel/umh.c

diff --git a/kernel/umh.c b/kernel/umh.c
index 7f255b5..b8c524d 100644
--- a/kernel/umh.c
+++ b/kernel/umh.c
@@ -14,6 +14,7 @@
 #include <linux/cred.h>
 #include <linux/file.h>
 #include <linux/fdtable.h>
+#include <linux/fs_struct.h>
 #include <linux/workqueue.h>
 #include <linux/security.h>
 #include <linux/mount.h>
@@ -76,6 +77,14 @@
 	spin_unlock_irq(&current->sighand->siglock);
 
 	/*
+	 * Initial kernel threads share ther FS with init, in order to
+	 * get the init root directory. But we've now created a new
+	 * thread that is going to execve a user process and has its own
+	 * 'struct fs_struct'. Reset umask to the default.
+	 */
+	current->fs->umask = 0022;
+
+	/*
 	 * Our parent (unbound workqueue) runs with elevated scheduling
 	 * priority. Avoid propagating that into the userspace child.
 	 */
@@ -475,6 +484,12 @@
 {
 	struct umh_info *umh_info = info->data;
 
+	/* cleanup if umh_pipe_setup() was successful but exec failed */
+	if (info->pid && info->retval) {
+		fput(umh_info->pipe_to_umh);
+		fput(umh_info->pipe_from_umh);
+	}
+
 	argv_free(info->argv);
 	umh_info->pid = info->pid;
 }
@@ -544,6 +559,11 @@
  * Runs a user-space application.  The application is started
  * asynchronously if wait is not set, and runs as a child of system workqueues.
  * (ie. it runs with full root capabilities and optimized affinity).
+ *
+ * Note: successful return value does not guarantee the helper was called at
+ * all. You can't rely on sub_info->{init,cleanup} being called even for
+ * UMH_WAIT_* wait modes as STATIC_USERMODEHELPER_PATH="" turns all helpers
+ * into a successful no-op.
  */
 int call_usermodehelper_exec(struct subprocess_info *sub_info, int wait)
 {