From 9fa4eb8e490a28de40964b1b0e583d8db4c7e57c Mon Sep 17 00:00:00 2001 From: NeilBrown <neilb@suse.com> Date: Fri, 23 Jun 2017 15:08:43 -0700 Subject: [PATCH] autofs: sanity check status reported with AUTOFS_DEV_IOCTL_FAIL If a positive status is passed with the AUTOFS_DEV_IOCTL_FAIL ioctl, autofs4_d_automount() will return ERR_PTR(status) with that status to follow_automount(), which will then dereference an invalid pointer. So treat a positive status the same as zero, and map to ENOENT. See comment in systemd src/core/automount.c::automount_send_ready(). Link: http://lkml.kernel.org/r/871sqwczx5.fsf@notabene.neil.brown.name Signed-off-by: NeilBrown <neilb@suse.com> Cc: Ian Kent <raven@themaw.net> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> --- fs/autofs4/dev-ioctl.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/autofs4/dev-ioctl.c b/fs/autofs4/dev-ioctl.c index 734cbf8d9676b..dd9f1bebb5a3a 100644 --- a/fs/autofs4/dev-ioctl.c +++ b/fs/autofs4/dev-ioctl.c @@ -344,7 +344,7 @@ static int autofs_dev_ioctl_fail(struct file *fp, int status; token = (autofs_wqt_t) param->fail.token; - status = param->fail.status ? param->fail.status : -ENOENT; + status = param->fail.status < 0 ? param->fail.status : -ENOENT; return autofs4_wait_release(sbi, token, status); } -- GitLab