From: Jing Xiangfeng <jingxiangfeng@huawei.com>
To: <maarten.lankhorst@linux.intel.com>, <mripard@kernel.org>,
<tzimmermann@suse.de>, <airlied@linux.ie>, <daniel@ffwll.ch>,
<nirmoy.das@amd.com>, <christian.koenig@amd.com>
Cc: <dri-devel@lists.freedesktop.org>, <linux-kernel@vger.kernel.org>,
<jingxiangfeng@huawei.com>
Subject: [PATCH] drm/mm: prevent a potential null-pointer dereference
Date: Thu, 10 Sep 2020 10:38:58 +0800 [thread overview]
Message-ID: <20200910023858.43759-1-jingxiangfeng@huawei.com> (raw)
The macro 'DECLARE_NEXT_HOLE_ADDR' may hit a potential null-pointer
dereference. So use 'entry' after checking it.
Fixes: 5fad79fd66ff ("drm/mm: cleanup and improve next_hole_*_addr()")
Signed-off-by: Jing Xiangfeng <jingxiangfeng@huawei.com>
---
drivers/gpu/drm/drm_mm.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/drm_mm.c b/drivers/gpu/drm/drm_mm.c
index a4a04d246135..6fcf70f71962 100644
--- a/drivers/gpu/drm/drm_mm.c
+++ b/drivers/gpu/drm/drm_mm.c
@@ -392,11 +392,14 @@ first_hole(struct drm_mm *mm,
#define DECLARE_NEXT_HOLE_ADDR(name, first, last) \
static struct drm_mm_node *name(struct drm_mm_node *entry, u64 size) \
{ \
- struct rb_node *parent, *node = &entry->rb_hole_addr; \
+ struct rb_node *parent, *node; \
\
- if (!entry || RB_EMPTY_NODE(node)) \
+ if (!entry) \
return NULL; \
\
+ node = &entry->rb_hole_addr; \
+ if (RB_EMPTY_NODE(node)) \
+ return NULL; \
if (usable_hole_addr(node->first, size)) { \
node = node->first; \
while (usable_hole_addr(node->last, size)) \
--
2.17.1
next reply other threads:[~2020-09-10 2:40 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-10 2:38 Jing Xiangfeng [this message]
2020-09-10 8:58 ` [PATCH] drm/mm: prevent a potential null-pointer dereference Christian König
2020-09-10 12:35 ` Jing Xiangfeng
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200910023858.43759-1-jingxiangfeng@huawei.com \
--to=jingxiangfeng@huawei.com \
--cc=airlied@linux.ie \
--cc=christian.koenig@amd.com \
--cc=daniel@ffwll.ch \
--cc=dri-devel@lists.freedesktop.org \
--cc=linux-kernel@vger.kernel.org \
--cc=maarten.lankhorst@linux.intel.com \
--cc=mripard@kernel.org \
--cc=nirmoy.das@amd.com \
--cc=tzimmermann@suse.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).