2024-04-01 09:11:41

by Kwangjin Ko

Subject: [PATCH 2/2] cxl/core: Fix incorrect array index in cxl_clear_event_record()

The variable 'i' should be incremented after dev_dbg(), or print
gen->hdr.handle instead. Otherwise, the handle value of the next loop
will be printed. Furthermore, in the final loop, accessing 'handles[i]'
will cause a buffer overflow.

Signed-off-by: Kwangjin Ko <[email protected]>
---
drivers/cxl/core/mbox.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
index a38531a055c8..84014aa01c95 100644
--- a/drivers/cxl/core/mbox.c
+++ b/drivers/cxl/core/mbox.c
@@ -913,9 +913,9 @@ static int cxl_clear_event_record(struct cxl_memdev_state *mds,
struct cxl_event_record_raw *raw = &get_pl->records[cnt];
struct cxl_event_generic *gen = &raw->event.generic;

- payload->handles[i++] = gen->hdr.handle;
dev_dbg(mds->cxlds.dev, "Event log '%d': Clearing %u\n", log,
- le16_to_cpu(payload->handles[i]));
+ le16_to_cpu(gen->hdr.handle));
+ payload->handles[i++] = gen->hdr.handle;

if (i == max_handles) {
payload->nr_recs = i;
--
2.34.1

2024-04-01 19:09:52

by Alison Schofield

Subject: Re: [PATCH 2/2] cxl/core: Fix incorrect array index in cxl_clear_event_record()

On Mon, Apr 01, 2024 at 06:10:56PM +0900, Kwangjin Ko wrote:
> The variable 'i' should be incremented after dev_dbg(), or print
> gen->hdr.handle instead. Otherwise, the handle value of the next loop
> will be printed. Furthermore, in the final loop, accessing 'handles[i]'
> will cause a buffer overflow.

This fix is already queued:
https://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl.git/?h=fixes

>
> Signed-off-by: Kwangjin Ko <[email protected]>
> ---
> drivers/cxl/core/mbox.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
> index a38531a055c8..84014aa01c95 100644
> --- a/drivers/cxl/core/mbox.c
> +++ b/drivers/cxl/core/mbox.c
> @@ -913,9 +913,9 @@ static int cxl_clear_event_record(struct cxl_memdev_state *mds,
> struct cxl_event_record_raw *raw = &get_pl->records[cnt];
> struct cxl_event_generic *gen = &raw->event.generic;
>
> - payload->handles[i++] = gen->hdr.handle;
> dev_dbg(mds->cxlds.dev, "Event log '%d': Clearing %u\n", log,
> - le16_to_cpu(payload->handles[i]));
> + le16_to_cpu(gen->hdr.handle));
> + payload->handles[i++] = gen->hdr.handle;
>
> if (i == max_handles) {
> payload->nr_recs = i;
> --
> 2.34.1
>