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-rw-r--r--fs/exec.c29
-rw-r--r--include/linux/binfmts.h4
2 files changed, 29 insertions, 4 deletions
diff --git a/fs/exec.c b/fs/exec.c
index 5f16500ac325..1843366be6ff 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1347,7 +1347,28 @@ int begin_new_exec(struct linux_binprm * bprm)
set_dumpable(current->mm, SUID_DUMP_USER);
perf_event_exec();
- __set_task_comm(me, kbasename(bprm->filename), true);
+
+ /*
+ * If the original filename was empty, alloc_bprm() made up a path
+ * that will probably not be useful to admins running ps or similar.
+ * Let's fix it up to be something reasonable.
+ */
+ if (bprm->comm_from_dentry) {
+ /*
+ * Hold RCU lock to keep the name from being freed behind our back.
+ * Use acquire semantics to make sure the terminating NUL from
+ * __d_alloc() is seen.
+ *
+ * Note, we're deliberately sloppy here. We don't need to care about
+ * detecting a concurrent rename and just want a terminated name.
+ */
+ rcu_read_lock();
+ __set_task_comm(me, smp_load_acquire(&bprm->file->f_path.dentry->d_name.name),
+ true);
+ rcu_read_unlock();
+ } else {
+ __set_task_comm(me, kbasename(bprm->filename), true);
+ }
/* An exec changes our domain. We are no longer part of the thread
group */
@@ -1521,11 +1542,13 @@ static struct linux_binprm *alloc_bprm(int fd, struct filename *filename, int fl
if (fd == AT_FDCWD || filename->name[0] == '/') {
bprm->filename = filename->name;
} else {
- if (filename->name[0] == '\0')
+ if (filename->name[0] == '\0') {
bprm->fdpath = kasprintf(GFP_KERNEL, "/dev/fd/%d", fd);
- else
+ bprm->comm_from_dentry = 1;
+ } else {
bprm->fdpath = kasprintf(GFP_KERNEL, "/dev/fd/%d/%s",
fd, filename->name);
+ }
if (!bprm->fdpath)
goto out_free;
diff --git a/include/linux/binfmts.h b/include/linux/binfmts.h
index e6c00e860951..3305c849abd6 100644
--- a/include/linux/binfmts.h
+++ b/include/linux/binfmts.h
@@ -42,7 +42,9 @@ struct linux_binprm {
* Set when errors can no longer be returned to the
* original userspace.
*/
- point_of_no_return:1;
+ point_of_no_return:1,
+ /* Set when "comm" must come from the dentry. */
+ comm_from_dentry:1;
struct file *executable; /* Executable to pass to the interpreter */
struct file *interpreter;
struct file *file;