Thread (19 messages) 19 messages, 4 authors, 2024-08-21

Re: [PATCH v2 7/9] vdpa: solidrun: Fix potential UB bug with devres

From: Christophe JAILLET <hidden>
Date: 2024-08-21 10:00:42
Also in: linux-arm-kernel, linux-block, linux-doc, linux-fpga, linux-gpio, linux-pci, lkml, stable, virtualization

Le 21/08/2024 à 09:18, Philipp Stanner a écrit :
quoted hunk ↗ jump to hunk
In psnet_open_pf_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 string on the heap through
devm_kasprintf().

Cc: stable@vger.kernel.org	# v6.3
Fixes: 51a8f9d7f587 ("virtio: vdpa: new SolidNET DPU driver.")
Reported-by: Christophe JAILLET <redacted>
Closes: https://lore.kernel.org/all/74e9109a-ac59-49e2-9b1d-d825c9c9f891@wanadoo.fr/ (local)
Suggested-by: Andy Shevchenko <andy@kernel.org>
Signed-off-by: Philipp Stanner <redacted>
---
  drivers/vdpa/solidrun/snet_main.c | 7 +++++--
  1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/vdpa/solidrun/snet_main.c b/drivers/vdpa/solidrun/snet_main.c
index 99428a04068d..4d42a05d70fc 100644
--- 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_config_ops = {
  
  static int psnet_open_pf_bar(struct pci_dev *pdev, struct psnet *psnet)
snet_open_vf_bar() also needs the same modification (see Andy's comment 
on patch 8/9)

CJ
quoted hunk ↗ jump to hunk
  {
-	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_dev *pdev, struct psnet *psnet)
  		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");
  
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help