6.11-stable review patch. If anyone has any objections, please let me know. ------------------ From: Philipp Stanner <pstanner@xxxxxxxxxx> commit 0b364cf53b20204e92bac7c6ebd1ee7d3ec62931 upstream. In psnet_open_pf_bar() and snet_open_vf_bar() a string later passed to pcim_iomap_regions() is placed on the stack. Neither pcim_iomap_regions() nor the functions it calls copy that string. Should the string later ever be used, this, consequently, causes undefined behavior since the stack frame will by then have disappeared. Fix the bug by allocating the strings on the heap through devm_kasprintf(). Cc: stable@xxxxxxxxxxxxxxx # v6.3 Fixes: 51a8f9d7f587 ("virtio: vdpa: new SolidNET DPU driver.") Reported-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx> Closes: https://lore.kernel.org/all/74e9109a-ac59-49e2-9b1d-d825c9c9f891@xxxxxxxxxx/ Suggested-by: Andy Shevchenko <andy@xxxxxxxxxx> Signed-off-by: Philipp Stanner <pstanner@xxxxxxxxxx> Reviewed-by: Stefano Garzarella <sgarzare@xxxxxxxxxx> Message-Id: <20241028074357.9104-3-pstanner@xxxxxxxxxx> Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/vdpa/solidrun/snet_main.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) --- a/drivers/vdpa/solidrun/snet_main.c +++ b/drivers/vdpa/solidrun/snet_main.c @@ -555,7 +555,7 @@ static const struct vdpa_config_ops snet static int psnet_open_pf_bar(struct pci_dev *pdev, struct psnet *psnet) { - char name[50]; + char *name; int ret, i, mask = 0; /* We don't know which BAR will be used to communicate.. * We will map every bar with len > 0. @@ -573,7 +573,10 @@ static int psnet_open_pf_bar(struct pci_ return -ENODEV; } - snprintf(name, sizeof(name), "psnet[%s]-bars", pci_name(pdev)); + name = devm_kasprintf(&pdev->dev, GFP_KERNEL, "psnet[%s]-bars", pci_name(pdev)); + if (!name) + return -ENOMEM; + ret = pcim_iomap_regions(pdev, mask, name); if (ret) { SNET_ERR(pdev, "Failed to request and map PCI BARs\n"); @@ -590,10 +593,13 @@ static int psnet_open_pf_bar(struct pci_ static int snet_open_vf_bar(struct pci_dev *pdev, struct snet *snet) { - char name[50]; + char *name; int ret; - snprintf(name, sizeof(name), "snet[%s]-bar", pci_name(pdev)); + name = devm_kasprintf(&pdev->dev, GFP_KERNEL, "snet[%s]-bars", pci_name(pdev)); + if (!name) + return -ENOMEM; + /* Request and map BAR */ ret = pcim_iomap_regions(pdev, BIT(snet->psnet->cfg.vf_bar), name); if (ret) {