while 'h' is packed and can be assumed to match the request payload,
req->rc is a struct p9_fcall which is not packed and that memcpy
could be wrong.
Fix this by copying each fields individually instead.
Reported-by: Christian Schoenebeck <[email protected]>
Suggested-by: Stefano Stabellini <[email protected]>
Link: https://lkml.kernel.org/r/alpine.DEB.2.22.394.2211211454540.1049131@ubuntu-linux-20-04-desktop
Signed-off-by: Dominique Martinet <[email protected]>
---
Follow up from the previous xen patch's review.
This isn't an immediate fix so I don't think this one should be rushed
in with the rest of the overflow fixes -- I'll let this sit a bit in
-next after reviews.
net/9p/trans_xen.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/net/9p/trans_xen.c b/net/9p/trans_xen.c
index 4665215bc98b..e8e3f54a837e 100644
--- a/net/9p/trans_xen.c
+++ b/net/9p/trans_xen.c
@@ -216,7 +216,9 @@ static void p9_xen_response(struct work_struct *work)
goto recv_error;
}
- memcpy(&req->rc, &h, sizeof(h));
+ req->rc.size = h.size;
+ req->rc.id = h.id;
+ req->rc.tag = h.tag;
req->rc.offset = 0;
masked_cons = xen_9pfs_mask(cons, XEN_9PFS_RING_SIZE(ring));
--
2.35.1
On Tue, 22 Nov 2022, Dominique Martinet wrote:
> while 'h' is packed and can be assumed to match the request payload,
> req->rc is a struct p9_fcall which is not packed and that memcpy
> could be wrong.
>
> Fix this by copying each fields individually instead.
>
> Reported-by: Christian Schoenebeck <[email protected]>
> Suggested-by: Stefano Stabellini <[email protected]>
> Link: https://lkml.kernel.org/r/alpine.DEB.2.22.394.2211211454540.1049131@ubuntu-linux-20-04-desktop
> Signed-off-by: Dominique Martinet <[email protected]>
Reviewed-by: Stefano Stabellini <[email protected]>
> ---
> Follow up from the previous xen patch's review.
>
> This isn't an immediate fix so I don't think this one should be rushed
> in with the rest of the overflow fixes -- I'll let this sit a bit in
> -next after reviews.
>
> net/9p/trans_xen.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/net/9p/trans_xen.c b/net/9p/trans_xen.c
> index 4665215bc98b..e8e3f54a837e 100644
> --- a/net/9p/trans_xen.c
> +++ b/net/9p/trans_xen.c
> @@ -216,7 +216,9 @@ static void p9_xen_response(struct work_struct *work)
> goto recv_error;
> }
>
> - memcpy(&req->rc, &h, sizeof(h));
> + req->rc.size = h.size;
> + req->rc.id = h.id;
> + req->rc.tag = h.tag;
> req->rc.offset = 0;
>
> masked_cons = xen_9pfs_mask(cons, XEN_9PFS_RING_SIZE(ring));
> --
> 2.35.1
>
On Tuesday, November 22, 2022 1:10:25 AM CET Dominique Martinet wrote:
> while 'h' is packed and can be assumed to match the request payload,
> req->rc is a struct p9_fcall which is not packed and that memcpy
> could be wrong.
>
> Fix this by copying each fields individually instead.
>
> Reported-by: Christian Schoenebeck <[email protected]>
> Suggested-by: Stefano Stabellini <[email protected]>
> Link: https://lkml.kernel.org/r/alpine.DEB.2.22.394.2211211454540.1049131@ubuntu-linux-20-04-desktop
> Signed-off-by: Dominique Martinet <[email protected]>
> ---
Reviewed-by: Christian Schoenebeck <[email protected]>
> Follow up from the previous xen patch's review.
>
> This isn't an immediate fix so I don't think this one should be rushed
> in with the rest of the overflow fixes -- I'll let this sit a bit in
> -next after reviews.
>
> net/9p/trans_xen.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/net/9p/trans_xen.c b/net/9p/trans_xen.c
> index 4665215bc98b..e8e3f54a837e 100644
> --- a/net/9p/trans_xen.c
> +++ b/net/9p/trans_xen.c
> @@ -216,7 +216,9 @@ static void p9_xen_response(struct work_struct *work)
> goto recv_error;
> }
>
> - memcpy(&req->rc, &h, sizeof(h));
> + req->rc.size = h.size;
> + req->rc.id = h.id;
> + req->rc.tag = h.tag;
> req->rc.offset = 0;
>
> masked_cons = xen_9pfs_mask(cons, XEN_9PFS_RING_SIZE(ring));
>