All of lore.kernel.org
 help / color / mirror / Atom feed
From: Chengfeng Ye <cyeaa@connect.ust.hk>
To: perex@perex.cz, tiwai@suse.com
Cc: alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org,
	Chengfeng Ye <cyeaa@connect.ust.hk>
Subject: [PATCH] sound/isa/gus: fix null pointer dereference on pointer block
Date: Sun, 24 Oct 2021 03:46:11 -0700	[thread overview]
Message-ID: <20211024104611.9919-1-cyeaa@connect.ust.hk> (raw)

The pointer block return from snd_gf1_dma_next_block could be
null, so there is a potential null pointer dereference issue.
Fix this by adding a null check before dereference.

Signed-off-by: Chengfeng Ye <cyeaa@connect.ust.hk>
---
 sound/isa/gus/gus_dma.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/sound/isa/gus/gus_dma.c b/sound/isa/gus/gus_dma.c
index a1c770d826dd..6d664dd8dde0 100644
--- a/sound/isa/gus/gus_dma.c
+++ b/sound/isa/gus/gus_dma.c
@@ -126,6 +126,8 @@ static void snd_gf1_dma_interrupt(struct snd_gus_card * gus)
 	}
 	block = snd_gf1_dma_next_block(gus);
 	spin_unlock(&gus->dma_lock);
+	if (!block)
+		return;
 	snd_gf1_dma_program(gus, block->addr, block->buf_addr, block->count, (unsigned short) block->cmd);
 	kfree(block);
 #if 0
-- 
2.17.1


WARNING: multiple messages have this Message-ID (diff)
From: Chengfeng Ye <cyeaa@connect.ust.hk>
To: perex@perex.cz, tiwai@suse.com
Cc: alsa-devel@alsa-project.org, Chengfeng Ye <cyeaa@connect.ust.hk>,
	linux-kernel@vger.kernel.org
Subject: [PATCH] sound/isa/gus: fix null pointer dereference on pointer block
Date: Sun, 24 Oct 2021 03:46:11 -0700	[thread overview]
Message-ID: <20211024104611.9919-1-cyeaa@connect.ust.hk> (raw)

The pointer block return from snd_gf1_dma_next_block could be
null, so there is a potential null pointer dereference issue.
Fix this by adding a null check before dereference.

Signed-off-by: Chengfeng Ye <cyeaa@connect.ust.hk>
---
 sound/isa/gus/gus_dma.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/sound/isa/gus/gus_dma.c b/sound/isa/gus/gus_dma.c
index a1c770d826dd..6d664dd8dde0 100644
--- a/sound/isa/gus/gus_dma.c
+++ b/sound/isa/gus/gus_dma.c
@@ -126,6 +126,8 @@ static void snd_gf1_dma_interrupt(struct snd_gus_card * gus)
 	}
 	block = snd_gf1_dma_next_block(gus);
 	spin_unlock(&gus->dma_lock);
+	if (!block)
+		return;
 	snd_gf1_dma_program(gus, block->addr, block->buf_addr, block->count, (unsigned short) block->cmd);
 	kfree(block);
 #if 0
-- 
2.17.1


             reply	other threads:[~2021-10-24 10:46 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-10-24 10:46 Chengfeng Ye [this message]
2021-10-24 10:46 ` [PATCH] sound/isa/gus: fix null pointer dereference on pointer block Chengfeng Ye
2021-10-26  6:02 ` Takashi Iwai
2021-10-26  6:02   ` Takashi Iwai
2021-10-26 12:51   ` 回复: " YE Chengfeng

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=20211024104611.9919-1-cyeaa@connect.ust.hk \
    --to=cyeaa@connect.ust.hk \
    --cc=alsa-devel@alsa-project.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=perex@perex.cz \
    --cc=tiwai@suse.com \
    /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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.