* [PATCH] pci: endpoint: Add missing NULL check for alloc_workqueue()
@ 2025-11-10 4:04 Haotian Zhang
2025-11-10 19:51 ` Frank Li
0 siblings, 1 reply; 2+ messages in thread
From: Haotian Zhang @ 2025-11-10 4:04 UTC (permalink / raw)
To: jdmason, dave.jiang, allenbh, mani, kwilczynski, kishon, bhelgaas
Cc: ntb, linux-pci, linux-kernel, Haotian Zhang
The alloc_workqueue() function can return NULL on memory allocation
failure. Without proper error checking, this leads to a NULL pointer
dereference when queue_work() is later called with the NULL workqueue
pointer in epf_ntb_epc_init().
Add a NULL check immediately after alloc_workqueue() and return -ENOMEM
on failure to prevent the driver from loading with an invalid workqueue
pointer.
Fixes: e35f56bb0330 ("PCI: endpoint: Support NTB transfer between RC and EP")
Fixes: 8b821cf76150 ("PCI: endpoint: Add EP function driver to provide NTB functionality")
Signed-off-by: Haotian Zhang <vulab@iscas.ac.cn>
---
drivers/pci/endpoint/functions/pci-epf-ntb.c | 4 ++++
drivers/pci/endpoint/functions/pci-epf-vntb.c | 4 ++++
2 files changed, 8 insertions(+)
diff --git a/drivers/pci/endpoint/functions/pci-epf-ntb.c b/drivers/pci/endpoint/functions/pci-epf-ntb.c
index e01a98e74d21..b3d96a2e3a8c 100644
--- a/drivers/pci/endpoint/functions/pci-epf-ntb.c
+++ b/drivers/pci/endpoint/functions/pci-epf-ntb.c
@@ -2126,6 +2126,10 @@ static int __init epf_ntb_init(void)
kpcintb_workqueue = alloc_workqueue("kpcintb", WQ_MEM_RECLAIM |
WQ_HIGHPRI, 0);
+ if (!kpcintb_workqueue) {
+ pr_err("Failed to allocate kpcintb workqueue\n");
+ return -ENOMEM;
+ }
ret = pci_epf_register_driver(&epf_ntb_driver);
if (ret) {
destroy_workqueue(kpcintb_workqueue);
diff --git a/drivers/pci/endpoint/functions/pci-epf-vntb.c b/drivers/pci/endpoint/functions/pci-epf-vntb.c
index 83e9ab10f9c4..79800f1fecc3 100644
--- a/drivers/pci/endpoint/functions/pci-epf-vntb.c
+++ b/drivers/pci/endpoint/functions/pci-epf-vntb.c
@@ -1534,6 +1534,10 @@ static int __init epf_ntb_init(void)
kpcintb_workqueue = alloc_workqueue("kpcintb", WQ_MEM_RECLAIM |
WQ_HIGHPRI, 0);
+ if (!kpcintb_workqueue) {
+ pr_err("Failed to allocate kpcintb workqueue\n");
+ return -ENOMEM;
+ }
ret = pci_epf_register_driver(&epf_ntb_driver);
if (ret) {
destroy_workqueue(kpcintb_workqueue);
--
2.50.1.windows.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] pci: endpoint: Add missing NULL check for alloc_workqueue()
2025-11-10 4:04 [PATCH] pci: endpoint: Add missing NULL check for alloc_workqueue() Haotian Zhang
@ 2025-11-10 19:51 ` Frank Li
0 siblings, 0 replies; 2+ messages in thread
From: Frank Li @ 2025-11-10 19:51 UTC (permalink / raw)
To: Haotian Zhang
Cc: jdmason, dave.jiang, allenbh, mani, kwilczynski, kishon, bhelgaas,
ntb, linux-pci, linux-kernel
On Mon, Nov 10, 2025 at 12:04:46PM +0800, Haotian Zhang wrote:
> The alloc_workqueue() function can return NULL on memory allocation
> failure. Without proper error checking, this leads to a NULL pointer
> dereference when queue_work() is later called with the NULL workqueue
> pointer in epf_ntb_epc_init().
>
> Add a NULL check immediately after alloc_workqueue() and return -ENOMEM
> on failure to prevent the driver from loading with an invalid workqueue
> pointer.
>
> Fixes: e35f56bb0330 ("PCI: endpoint: Support NTB transfer between RC and EP")
> Fixes: 8b821cf76150 ("PCI: endpoint: Add EP function driver to provide NTB functionality")
> Signed-off-by: Haotian Zhang <vulab@iscas.ac.cn>
> ---
> drivers/pci/endpoint/functions/pci-epf-ntb.c | 4 ++++
> drivers/pci/endpoint/functions/pci-epf-vntb.c | 4 ++++
> 2 files changed, 8 insertions(+)
>
> diff --git a/drivers/pci/endpoint/functions/pci-epf-ntb.c b/drivers/pci/endpoint/functions/pci-epf-ntb.c
> index e01a98e74d21..b3d96a2e3a8c 100644
> --- a/drivers/pci/endpoint/functions/pci-epf-ntb.c
> +++ b/drivers/pci/endpoint/functions/pci-epf-ntb.c
> @@ -2126,6 +2126,10 @@ static int __init epf_ntb_init(void)
>
> kpcintb_workqueue = alloc_workqueue("kpcintb", WQ_MEM_RECLAIM |
> WQ_HIGHPRI, 0);
> + if (!kpcintb_workqueue) {
> + pr_err("Failed to allocate kpcintb workqueue\n");
> + return -ENOMEM;
> + }
Can we direct use system_highpri_wq?
Frank Li
> ret = pci_epf_register_driver(&epf_ntb_driver);
> if (ret) {
> destroy_workqueue(kpcintb_workqueue);
> diff --git a/drivers/pci/endpoint/functions/pci-epf-vntb.c b/drivers/pci/endpoint/functions/pci-epf-vntb.c
> index 83e9ab10f9c4..79800f1fecc3 100644
> --- a/drivers/pci/endpoint/functions/pci-epf-vntb.c
> +++ b/drivers/pci/endpoint/functions/pci-epf-vntb.c
> @@ -1534,6 +1534,10 @@ static int __init epf_ntb_init(void)
>
> kpcintb_workqueue = alloc_workqueue("kpcintb", WQ_MEM_RECLAIM |
> WQ_HIGHPRI, 0);
> + if (!kpcintb_workqueue) {
> + pr_err("Failed to allocate kpcintb workqueue\n");
> + return -ENOMEM;
> + }
> ret = pci_epf_register_driver(&epf_ntb_driver);
> if (ret) {
> destroy_workqueue(kpcintb_workqueue);
> --
> 2.50.1.windows.1
>
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