From: Takashi Iwai <tiwai@suse.de>
To: alsa-devel@alsa-project.org
Subject: [PATCH] ALSA: PCM: Fix NULL dereference at mmap checks
Date: Sun, 7 Nov 2021 17:39:11 +0100 [thread overview]
Message-ID: <20211107163911.13534-1-tiwai@suse.de> (raw)
The recent refactoring of mmap handling caused Oops on some devices
that don't use the standard memory allocations. This patch addresses
it by allowing snd_dma_buffer_mmap() helper to receive the NULL
pointer dmab argument (and return an error appropriately).
Fixes: a202bd1ad86d ("ALSA: core: Move mmap handler into memalloc ops")
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
---
sound/core/memalloc.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/sound/core/memalloc.c b/sound/core/memalloc.c
index 0145dabda56d..de7e9d2df39d 100644
--- a/sound/core/memalloc.c
+++ b/sound/core/memalloc.c
@@ -183,8 +183,11 @@ EXPORT_SYMBOL_GPL(snd_devm_alloc_dir_pages);
int snd_dma_buffer_mmap(struct snd_dma_buffer *dmab,
struct vm_area_struct *area)
{
- const struct snd_malloc_ops *ops = snd_dma_get_ops(dmab);
+ const struct snd_malloc_ops *ops;
+ if (!dmab)
+ return -ENOENT;
+ ops = snd_dma_get_ops(dmab);
if (ops && ops->mmap)
return ops->mmap(dmab, area);
else
--
2.31.1
reply other threads:[~2021-11-07 16:40 UTC|newest]
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