[PATCH 0/1] firewire: fix memory leak for payload of request subaction to IEC 61883-1 FCP region
Hi,
This single patch fixes a bug of Linux FireWire subsystem for kernel v2.6.33 or later. In detail, please refer patch comment.
My intension of this cover-letter is to request sound subsystem maintainer to send it to mainline since upstream of Linux FireWire subsystem is already inactive.
To Iwai-san, I would be pleased if you alternatively send it to mainline.
Thanks
Takashi Sakamoto (1): firewire: fix memory leak for payload of request subaction to IEC 61883-1 FCP region
drivers/firewire/core-cdev.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
This patch is fix for Linux kernel v2.6.33 or later.
For request subaction to IEC 61883-1 FCP region, Linux FireWire subsystem have had an issue of use-after-free. The subsystem allows multiple user space listeners to the region, while data of the payload was likely released before the listeners execute read(2) to access to it for copying to user space.
The issue was fixed by a commit 281e20323ab7 ("firewire: core: fix use-after-free regression in FCP handler"). The object of payload is duplicated in kernel space for each listener. When the listener executes ioctl(2) with FW_CDEV_IOC_SEND_RESPONSE request, the object is going to be released.
However, it causes memory leak since the commit relies on call of release_request() in drivers/firewire/core-cdev.c. Against the expectation, the function is never called due to the design of release_client_resource(). The function delegates release task to caller when called with non-NULL fourth argument. The implementation of ioctl_send_response() is the case. It should release the object explicitly.
This commit fixes the bug.
Cc: stable@vger.kernel.org Fixes: 281e20323ab7 ("firewire: core: fix use-after-free regression in FCP handler") Signed-off-by: Takashi Sakamoto o-takashi@sakamocchi.jp --- drivers/firewire/core-cdev.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/firewire/core-cdev.c b/drivers/firewire/core-cdev.c index 9c89f7d53e99..958aa4662ccb 100644 --- a/drivers/firewire/core-cdev.c +++ b/drivers/firewire/core-cdev.c @@ -819,8 +819,10 @@ static int ioctl_send_response(struct client *client, union ioctl_arg *arg)
r = container_of(resource, struct inbound_transaction_resource, resource); - if (is_fcp_request(r->request)) + if (is_fcp_request(r->request)) { + kfree(r->data); goto out; + }
if (a->length != fw_get_response_length(r->request)) { ret = -EINVAL;
On Tue, 17 Jan 2023 10:06:09 +0100, Takashi Sakamoto wrote:
Hi,
This single patch fixes a bug of Linux FireWire subsystem for kernel v2.6.33 or later. In detail, please refer patch comment.
My intension of this cover-letter is to request sound subsystem maintainer to send it to mainline since upstream of Linux FireWire subsystem is already inactive.
To Iwai-san, I would be pleased if you alternatively send it to mainline.
OK, I applied it now.
thanks,
Takashi
participants (2)
-
Takashi Iwai
-
Takashi Sakamoto