In snd_gf1_mem_xfree(), there is an if statement on line 72 and line 74
to check whether block->next is NULL:
if (block->next)
When block->next is NULL, block->next is used on line 84:
block->next->prev = block->prev;
Thus, a possible null-pointer dereference may occur in this case.
To fix this possible bug, block->next is checked before using it.
This bug is found by a static analysis tool STCheck written by us.
Signed-off-by: Jia-Ju Bai <baijiaju1990@xxxxxxxxx>
---
sound/isa/gus/gus_mem.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/sound/isa/gus/gus_mem.c b/sound/isa/gus/gus_mem.c
index cb02d18dde60..ed6205b88057 100644
--- a/sound/isa/gus/gus_mem.c
+++ b/sound/isa/gus/gus_mem.c
@@ -81,7 +81,8 @@ int snd_gf1_mem_xfree(struct snd_gf1_mem * alloc, struct snd_gf1_mem_block * blo
if (block->prev)
block->prev->next = NULL;
} else {
- block->next->prev = block->prev;
+ if (block->next)
+ block->next->prev = block->prev;
if (block->prev)
block->prev->next = block->next;
}
--
2.17.0
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