* [PATCH v3] vfio: Clear the caps->buf to NULL after free
@ 2022-06-29 2:29 Schspa Shi
2022-06-30 19:51 ` Alex Williamson
0 siblings, 1 reply; 2+ messages in thread
From: Schspa Shi @ 2022-06-29 2:29 UTC (permalink / raw)
To: alex.williamson, cohuck; +Cc: kvm, linux-kernel, Schspa Shi
On buffer resize failure, vfio_info_cap_add() will free the buffer,
report zero for the size, and return -ENOMEM. As additional
hardening, also clear the buffer pointer to prevent any chance of a
double free.
Signed-off-by: Schspa Shi <schspa@gmail.com>
--
Changelog:
v1 -> v2:
- Remove incorrect double free report in commit message.
v2 -> v3:
- Update commit comment as Alex advised.
---
drivers/vfio/vfio.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
index 61e71c1154be..a0fb93866f61 100644
--- a/drivers/vfio/vfio.c
+++ b/drivers/vfio/vfio.c
@@ -1812,6 +1812,7 @@ struct vfio_info_cap_header *vfio_info_cap_add(struct vfio_info_cap *caps,
buf = krealloc(caps->buf, caps->size + size, GFP_KERNEL);
if (!buf) {
kfree(caps->buf);
+ caps->buf = NULL;
caps->size = 0;
return ERR_PTR(-ENOMEM);
}
--
2.29.0
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH v3] vfio: Clear the caps->buf to NULL after free
2022-06-29 2:29 [PATCH v3] vfio: Clear the caps->buf to NULL after free Schspa Shi
@ 2022-06-30 19:51 ` Alex Williamson
0 siblings, 0 replies; 2+ messages in thread
From: Alex Williamson @ 2022-06-30 19:51 UTC (permalink / raw)
To: Schspa Shi; +Cc: cohuck, kvm, linux-kernel
On Wed, 29 Jun 2022 10:29:48 +0800
Schspa Shi <schspa@gmail.com> wrote:
> On buffer resize failure, vfio_info_cap_add() will free the buffer,
> report zero for the size, and return -ENOMEM. As additional
> hardening, also clear the buffer pointer to prevent any chance of a
> double free.
>
> Signed-off-by: Schspa Shi <schspa@gmail.com>
>
Applied to vfio next branch for v5.20. Thanks,
Alex
^ permalink raw reply [flat|nested] 2+ messages in thread
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2022-06-30 19:51 ` Alex Williamson
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