From: Alexandr Sapozhnikov <[email protected]>
After having been compared to a NULL value at core.c:813,
pointer '(**sq->ctrl).sqs' is dereferenced at core.c:838.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Signed-off-by: Alexandr Sapozhnikov <[email protected]>
---
drivers/nvme/target/core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/nvme/target/core.c b/drivers/nvme/target/core.c
index 06f0c587f343..5a67d2bc0c55 100644
--- a/drivers/nvme/target/core.c
+++ b/drivers/nvme/target/core.c
@@ -827,7 +827,7 @@ void nvmet_sq_destroy(struct nvmet_sq *sq)
*/
ctrl = sq->ctrl;
- if (ctrl) {
+ if (ctrl && ctrl->sqs) {
/*
* The teardown flow may take some time, and the host may not
* send us keep-alive during this period, hence reset the
--
2.39.2
On 6/7/24 06:43, Alexander Sapozhnikov wrote:
> From: Alexandr Sapozhnikov <[email protected]>
>
> After having been compared to a NULL value at core.c:813,
> pointer '(**sq->ctrl).sqs' is dereferenced at core.c:838.
really didn't understand the NULL check mentioned above :-
812 */
813 if (ctrl && ctrl->sqs && ctrl->sqs[0] == sq)
814 nvmet_async_events_failall(ctrl);
from what I know it checks the non NULL ctrl->sqs and then
validates the sq is admin queue before calling failing the async
events ...
> Found by Linux Verification Center (linuxtesting.org) with SVACE.
>
> Signed-off-by: Alexandr Sapozhnikov <[email protected]>
> ---
> drivers/nvme/target/core.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/nvme/target/core.c b/drivers/nvme/target/core.c
> index 06f0c587f343..5a67d2bc0c55 100644
> --- a/drivers/nvme/target/core.c
> +++ b/drivers/nvme/target/core.c
> @@ -827,7 +827,7 @@ void nvmet_sq_destroy(struct nvmet_sq *sq)
> */
> ctrl = sq->ctrl;
>
> - if (ctrl) {
> + if (ctrl && ctrl->sqs) {
> /*
> * The teardown flow may take some time, and the host may not
> * send us keep-alive during this period, hence reset the
do we need more fine grained check where ctrl->sqs is actually
accessed :-
diff --git a/drivers/nvme/target/core.c b/drivers/nvme/target/core.c
index 06f0c587f343..a70cad5a6262 100644
--- a/drivers/nvme/target/core.c
+++ b/drivers/nvme/target/core.c
@@ -835,7 +835,8 @@ void nvmet_sq_destroy(struct nvmet_sq *sq)
* controller teardown as a result of a keep-alive
expiration.
*/
ctrl->reset_tbkas = true;
- sq->ctrl->sqs[sq->qid] = NULL;
+ if (sq->ctrl->sqs)
+ sq->ctrl->sqs[sq->qid] = NULL;
nvmet_ctrl_put(ctrl);
sq->ctrl = NULL; /* allows reusing the queue later */
}
-ck
> After having been compared to a NULL value at core.c:813,
> pointer '(**sq->ctrl).sqs' is dereferenced at core.c:838.
* Please choose another imperative wording for an improved change description.
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst?h=v6.10-rc2#n94
* Would you like to add the tag “Fixes” accordingly?
* How do you think about to use the summary phrase “Avoid null pointer dereference
in nvmet_sq_destroy()”?
* Is the subsystem specification “nvmet” more appropriate?
Regards,
Markus
On 07/06/2024 16:43, Alexander Sapozhnikov wrote:
> From: Alexandr Sapozhnikov <[email protected]>
>
> After having been compared to a NULL value at core.c:813,
> pointer '(**sq->ctrl).sqs' is dereferenced at core.c:838.
>
> Found by Linux Verification Center (linuxtesting.org) with SVACE.
>
> Signed-off-by: Alexandr Sapozhnikov <[email protected]>
> ---
> drivers/nvme/target/core.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/nvme/target/core.c b/drivers/nvme/target/core.c
> index 06f0c587f343..5a67d2bc0c55 100644
> --- a/drivers/nvme/target/core.c
> +++ b/drivers/nvme/target/core.c
> @@ -827,7 +827,7 @@ void nvmet_sq_destroy(struct nvmet_sq *sq)
> */
> ctrl = sq->ctrl;
>
> - if (ctrl) {
> + if (ctrl && ctrl->sqs) {
> /*
> * The teardown flow may take some time, and the host may not
> * send us keep-alive during this period, hence reset the
This is a redundant check. sq->ctrl and sq->ctrl->sqs have the same
lifetime. If
sq->ctrl was assigned, it means that it was allocated and needs a final
put to
fully cleanup. ctrl->sqs is allocated in nvmet_alloc_ctrl and freed in
nvmet_free_ctrl
which is the final reference.