Commit db803036 authored May 08, 2020 by Vincent Minet Committed by Jakub Kicinski May 08, 2020

umh: fix memory leak on execve failure

If a UMH process created by fork_usermode_blob() fails to execute,
a pair of struct file allocated by umh_pipe_setup() will leak.

Under normal conditions, the caller (like bpfilter) needs to manage the
lifetime of the UMH and its two pipes. But when fork_usermode_blob()
fails, the caller doesn't really have a way to know what needs to be
done. It seems better to do the cleanup ourselves in this case.

Fixes: 449325b5 ("umh: introduce fork_usermode_blob() helper")
Signed-off-by: Vincent Minet <v.minet@criteo.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

parent 14d8f748

kernel/umh.c

+6 −0

Original line number	Diff line number	Diff line
		@@ -475,6 +475,12 @@ static void umh_clean_and_save_pid(struct subprocess_info *info)
		{
		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;
		}

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