Commit 632a465e authored by Manivannan Sadhasivam's avatar Manivannan Sadhasivam Committed by liwei
Browse files

PCI: endpoint: pci-epf-test: Make use of cached 'epc_features' in pci_epf_test_core_init() 

mainline inclusion
from mainline-v6.11-rc1
commit 5a5095a8bd1bd349cce1c879e5e44407a34dda8a
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAKQ5P
CVE: CVE-2024-43824

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=5a5095a8bd1bd349cce1c879e5e44407a34dda8a

--------------------------------

Instead of getting the epc_features from pci_epc_get_features() API, use
the cached pci_epf_test::epc_features value to avoid the NULL check. Since
the NULL check is already performed in pci_epf_test_bind(), having one more
check in pci_epf_test_core_init() is redundant and it is not possible to
hit the NULL pointer dereference.

Also with commit a01e7214bef9 ("PCI: endpoint: Remove "core_init_notifier"
flag"), 'epc_features' got dereferenced without the NULL check, leading to
the following false positive Smatch warning:

  drivers/pci/endpoint/functions/pci-epf-test.c:784 pci_epf_test_core_init() error: we previously assumed 'epc_features' could be null (see line 747)

Thus, remove the redundant NULL check and also use the epc_features::
{msix_capable/msi_capable} flags directly to avoid local variables.

[kwilczynski: commit log]
Fixes: 5e50ee27 ("PCI: pci-epf-test: Add support to defer core initialization")
Closes: https://lore.kernel.org/linux-pci/024b5826-7180-4076-ae08-57d2584cca3f@moroto.mountain
Link: https://lore.kernel.org/linux-pci/20240418-pci-epf-test-fix-v2-1-eacd54831444@linaro.org


Reported-by: default avatarDan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: default avatarManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: default avatarKrzysztof Wilczyński <kwilczynski@kernel.org>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: default avatarFrank Li <Frank.Li@nxp.com>
Reviewed-by: default avatarNiklas Cassel <cassel@kernel.org>

Conflicts:
	drivers/pci/endpoint/functions/pci-epf-test.c
[context conflicts]
Signed-off-by: default avatarliwei <liwei728@huawei.com>
parent 063fb5b6

drivers/pci/endpoint/functions/pci-epf-test.c

+3 −11
Original line number Diff line number Diff line
@@ -750,19 +750,11 @@ static int pci_epf_test_core_init(struct pci_epf *epf) 
{

	struct pci_epf_test *epf_test = epf_get_drvdata(epf);

	struct pci_epf_header *header = epf->header;

	const struct pci_epc_features *epc_features;

	const struct pci_epc_features *epc_features = epf_test->epc_features;

	struct pci_epc *epc = epf->epc;

	struct device *dev = &epf->dev;

	bool msix_capable = false;

	bool msi_capable = true;

	int ret;



	epc_features = pci_epc_get_features(epc, epf->func_no, epf->vfunc_no);

	if (epc_features) {

		msix_capable = epc_features->msix_capable;

		msi_capable = epc_features->msi_capable;

	}



	if (epf->vfunc_no <= 1) {

		ret = pci_epc_write_header(epc, epf->func_no, epf->vfunc_no, header);

		if (ret) {
@@ -775,7 +767,7 @@ static int pci_epf_test_core_init(struct pci_epf *epf) 
	if (ret)

		return ret;



	if (msi_capable) {

	if (epc_features->msi_capable) {

		ret = pci_epc_set_msi(epc, epf->func_no, epf->vfunc_no,

				      epf->msi_interrupts);

		if (ret) {
@@ -784,7 +776,7 @@ static int pci_epf_test_core_init(struct pci_epf *epf) 
		}

	}



	if (msix_capable) {

	if (epc_features->msix_capable) {

		ret = pci_epc_set_msix(epc, epf->func_no, epf->vfunc_no,

				       epf->msix_interrupts,

				       epf_test->test_reg_bar,