2022-06-30 01:45:19

by Jianglei Nie

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Subject: [PATCH] usb: host: xhci: Fix potential memory leak in xhci_alloc_stream_info()

xhci_alloc_stream_info() allocates stream context array for stream_info
->stream_ctx_array with xhci_alloc_stream_ctx(). When some error occurs,
stream_info->stream_ctx_array is not released, which will lead to a
memory leak.

We can fix it by releasing the stream_info->stream_ctx_array with
xhci_free_stream_ctx() on the error path to avoid the potential memory
leak.

Signed-off-by: Jianglei Nie <[email protected]>
---
drivers/usb/host/xhci-mem.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index 8c19e151a945..a71d3a873467 100644
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -648,8 +648,13 @@ struct xhci_stream_info *xhci_alloc_stream_info(struct xhci_hcd *xhci,
/* Allocate everything needed to free the stream rings later */
stream_info->free_streams_command =
xhci_alloc_command_with_ctx(xhci, true, mem_flags);
- if (!stream_info->free_streams_command)
+ if (!stream_info->free_streams_command) {
+ xhci_free_stream_ctx(xhci,
+ stream_info->num_stream_ctxs,
+ stream_info->stream_ctx_array,
+ stream_info->ctx_array_dma);
goto cleanup_ctx;
+ }

INIT_RADIX_TREE(&stream_info->trb_address_map, GFP_ATOMIC);

@@ -700,6 +705,10 @@ struct xhci_stream_info *xhci_alloc_stream_info(struct xhci_hcd *xhci,
stream_info->stream_rings[cur_stream] = NULL;
}
}
+ xhci_free_stream_ctx(xhci,
+ stream_info->num_stream_ctxs,
+ stream_info->stream_ctx_array,
+ stream_info->ctx_array_dma);
xhci_free_command(xhci, stream_info->free_streams_command);
cleanup_ctx:
kfree(stream_info->stream_rings);
--
2.25.1


2022-06-30 06:59:07

by Greg Kroah-Hartman

[permalink] [raw]
Subject: Re: [PATCH] usb: host: xhci: Fix potential memory leak in xhci_alloc_stream_info()

On Thu, Jun 30, 2022 at 09:10:08AM +0800, Jianglei Nie wrote:
> xhci_alloc_stream_info() allocates stream context array for stream_info
> ->stream_ctx_array with xhci_alloc_stream_ctx(). When some error occurs,
> stream_info->stream_ctx_array is not released, which will lead to a
> memory leak.
>
> We can fix it by releasing the stream_info->stream_ctx_array with
> xhci_free_stream_ctx() on the error path to avoid the potential memory
> leak.
>
> Signed-off-by: Jianglei Nie <[email protected]>
> ---
> drivers/usb/host/xhci-mem.c | 11 ++++++++++-
> 1 file changed, 10 insertions(+), 1 deletion(-)

What commit id does this fix?

thanks,

greg k-h

2022-06-30 10:36:42

by Mathias Nyman

[permalink] [raw]
Subject: Re: [PATCH] usb: host: xhci: Fix potential memory leak in xhci_alloc_stream_info()

On 30.6.2022 4.10, Jianglei Nie wrote:
> xhci_alloc_stream_info() allocates stream context array for stream_info
> ->stream_ctx_array with xhci_alloc_stream_ctx(). When some error occurs,
> stream_info->stream_ctx_array is not released, which will lead to a
> memory leak.

Nice catch, thanks

>
> We can fix it by releasing the stream_info->stream_ctx_array with
> xhci_free_stream_ctx() on the error path to avoid the potential memory
> leak.
>

Looks like the goto labels were a bit messed up from the beginning.
There are a couple "goto cleanup_ctx" lines in the code, but
cleanup_ctx never freed the ctx.

> Signed-off-by: Jianglei Nie <[email protected]>
> ---
> drivers/usb/host/xhci-mem.c | 11 ++++++++++-
> 1 file changed, 10 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
> index 8c19e151a945..a71d3a873467 100644
> --- a/drivers/usb/host/xhci-mem.c
> +++ b/drivers/usb/host/xhci-mem.c
> @@ -648,8 +648,13 @@ struct xhci_stream_info *xhci_alloc_stream_info(struct xhci_hcd *xhci,
> /* Allocate everything needed to free the stream rings later */
> stream_info->free_streams_command =
> xhci_alloc_command_with_ctx(xhci, true, mem_flags);
> - if (!stream_info->free_streams_command)
> + if (!stream_info->free_streams_command) {
> + xhci_free_stream_ctx(xhci,
> + stream_info->num_stream_ctxs,
> + stream_info->stream_ctx_array,
> + stream_info->ctx_array_dma);
> goto cleanup_ctx;
> + }
>
> INIT_RADIX_TREE(&stream_info->trb_address_map, GFP_ATOMIC);
>
> @@ -700,6 +705,10 @@ struct xhci_stream_info *xhci_alloc_stream_info(struct xhci_hcd *xhci,
> stream_info->stream_rings[cur_stream] = NULL;
> }
> }
> + xhci_free_stream_ctx(xhci,
> + stream_info->num_stream_ctxs,
> + stream_info->stream_ctx_array,
> + stream_info->ctx_array_dma);
> xhci_free_command(xhci, stream_info->free_streams_command);
> cleanup_ctx:
> kfree(stream_info->stream_rings);

How about:

diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index 8c19e151a945..f7cac1af51c5 100644
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -641,7 +641,7 @@ struct xhci_stream_info *xhci_alloc_stream_info(struct xhci_hcd *xhci,
num_stream_ctxs, &stream_info->ctx_array_dma,
mem_flags);
if (!stream_info->stream_ctx_array)
- goto cleanup_ctx;
+ goto cleanup_rings;
memset(stream_info->stream_ctx_array, 0,
sizeof(struct xhci_stream_ctx)*num_stream_ctxs);

@@ -702,6 +702,10 @@ struct xhci_stream_info *xhci_alloc_stream_info(struct xhci_hcd *xhci,
}
xhci_free_command(xhci, stream_info->free_streams_command);
cleanup_ctx:
+ xhci_free_stream_ctx(xhci, stream_info->num_stream_ctxs,
+ stream_info->stream_ctx_array,
+ stream_info->ctx_array_dma);
+cleanup_rings:
kfree(stream_info->stream_rings);
cleanup_info:

2022-06-30 10:37:36

by Mathias Nyman

[permalink] [raw]
Subject: Re: [PATCH] usb: host: xhci: Fix potential memory leak in xhci_alloc_stream_info()

>
> How about:
>
> diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
> index 8c19e151a945..f7cac1af51c5 100644
> --- a/drivers/usb/host/xhci-mem.c
> +++ b/drivers/usb/host/xhci-mem.c
> @@ -641,7 +641,7 @@ struct xhci_stream_info *xhci_alloc_stream_info(struct xhci_hcd *xhci,
>                         num_stream_ctxs, &stream_info->ctx_array_dma,
>                         mem_flags);
>         if (!stream_info->stream_ctx_array)
> -               goto cleanup_ctx;
> +               goto cleanup_rings;

Small sidenote, "cleanup_rings" label was already in use, so maybe something like
"cleanup_ring_array" could be used

Thanks
-Mathias