From: Manivannan Sadhasivam Date: Tue, 7 Apr 2026 12:44:20 +0000 (+0530) Subject: PCI: endpoint: pci-epf-vntb: Add check to detect 'db_count' value of 0 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=33bd1ea748bc897c4d13437284e08c658e8d1340;p=thirdparty%2Flinux.git PCI: endpoint: pci-epf-vntb: Add check to detect 'db_count' value of 0 epf_ntb->db_count value should be within 1 to MAX_DB_COUNT. Current code only checks for the upper bound, while the lower bound is unchecked. This can cause a lot of issues in the driver if the user passes 'db_count' as 0. Add a check for 0 also. While at it, remove the redundant 'db_count' assignment. Fixes: e35f56bb0330 ("PCI: endpoint: Support NTB transfer between RC and EP") Signed-off-by: Manivannan Sadhasivam Signed-off-by: Manivannan Sadhasivam Signed-off-by: Bjorn Helgaas Reviewed-by: Koichiro Den Reviewed-by: Frank Li Link: https://patch.msgid.link/20260407124421.282766-2-mani@kernel.org --- diff --git a/drivers/pci/endpoint/functions/pci-epf-vntb.c b/drivers/pci/endpoint/functions/pci-epf-vntb.c index b493a300da4d..d59870fd3430 100644 --- a/drivers/pci/endpoint/functions/pci-epf-vntb.c +++ b/drivers/pci/endpoint/functions/pci-epf-vntb.c @@ -488,7 +488,6 @@ static int epf_ntb_configure_interrupt(struct epf_ntb *ntb) { const struct pci_epc_features *epc_features; struct device *dev; - u32 db_count; int ret; dev = &ntb->epf->dev; @@ -500,14 +499,12 @@ static int epf_ntb_configure_interrupt(struct epf_ntb *ntb) return -EINVAL; } - db_count = ntb->db_count; - if (db_count > MAX_DB_COUNT) { - dev_err(dev, "DB count cannot be more than %d\n", MAX_DB_COUNT); + if (!ntb->db_count || ntb->db_count > MAX_DB_COUNT) { + dev_err(dev, "DB count %d out of range (1 - %d)\n", + ntb->db_count, MAX_DB_COUNT); return -EINVAL; } - ntb->db_count = db_count; - if (epc_features->msi_capable) { ret = pci_epc_set_msi(ntb->epf->epc, ntb->epf->func_no,