diff mbox series

sound/isa/gus: fix null pointer dereference on pointer block

Message ID 20211024104611.9919-1-cyeaa@connect.ust.hk (mailing list archive)
State Accepted
Commit a0d21bb3279476c777434c40d969ea88ca64f9aa
Headers show
Series sound/isa/gus: fix null pointer dereference on pointer block | expand

Commit Message

YE Chengfeng Oct. 24, 2021, 10:46 a.m. UTC 
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 mbox series

Patch

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