linux-kernel - [PATCH v5] PCI: rcar-ep: Fix the issue of the name parameter when calling devm_request_mem

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-ID: <tencent_DBDCC19D60F361119E76919ADAB25EC13C06@qq.com>
Date: Thu,  9 Jan 2025 08:50:18 +0800
From: kingdix10@...com
To: marek.vasut+renesas@...il.com,
	yoshihiro.shimoda.uh@...esas.com,
	lpieralisi@...nel.org,
	kw@...ux.com,
	manivannan.sadhasivam@...aro.org,
	robh@...nel.org,
	bhelgaas@...gle.com,
	prabhakar.csengg@...il.com,
	biju.das.jz@...renesas.com,
	geert@...ux-m68k.org,
	prabhakar.mahadev-lad.rj@...renesas.com
Cc: linux-pci@...r.kernel.org,
	linux-renesas-soc@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	King Dix <kingdix10@...com>
Subject: [PATCH v5] PCI: rcar-ep: Fix the issue of the name parameter when calling devm_request_mem_region()

From: King Dix <kingdix10@...com>

When using devm_request_mem_region() to request a resource and the name
parameter is a stack string variable, it may cause errors when executing
the command `cat /proc/iomem`. Depending on the content of the memory, the
manifestations of errors may vary. One possible output may be as follows:

$ cat /proc/iomem
30000000-37ffffff :
38000000-3fffffff :

Another possibility is that garbage characters may appear after the colon.
In very rare cases, if no NUL-terminator is found in memory, the system
might crash because the string iterator may access unmapped memory above
the stack.

Fix this by replacing outbound_name with the name of the previously
requested resource. With the patch applied, the output is as follows:

$ cat /proc/iomem
30000000-37ffffff : memory2
38000000-3fffffff : memory3

Fixes: 2a6d0d63d999 ("PCI: rcar: Add endpoint mode support")

Signed-off-by: King Dix <kingdix10@...com>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@...renesas.com>
Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@...renesas.com>
---
Changes in v5:
  - Add examples of error outputs to the comment.
Changes in v4:
  - Add more information to the comment.
Changes in v3:
  - Fix the spelling issue in the comment.
Changes in v2:
  - Fix the code indentation issue.
---
 drivers/pci/controller/pcie-rcar-ep.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/pci/controller/pcie-rcar-ep.c b/drivers/pci/controller/pcie-rcar-ep.c
index 047e2cef5afc..c5e0d025bc43 100644
--- a/drivers/pci/controller/pcie-rcar-ep.c
+++ b/drivers/pci/controller/pcie-rcar-ep.c
@@ -107,7 +107,7 @@ static int rcar_pcie_parse_outbound_ranges(struct rcar_pcie_endpoint *ep,
 		}
 		if (!devm_request_mem_region(&pdev->dev, res->start,
 					     resource_size(res),
-					     outbound_name)) {
+					     res->name)) {
 			dev_err(pcie->dev, "Cannot request memory region %s.\n",
 				outbound_name);
 			return -EIO;
-- 
2.43.0