Patch "PCI: rcar-ep: Fix incorrect variable used when calling devm_request_mem_region()" has been added to the 5.15-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    PCI: rcar-ep: Fix incorrect variable used when calling devm_request_mem_region()

to the 5.15-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     pci-rcar-ep-fix-incorrect-variable-used-when-calling.patch
and it can be found in the queue-5.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 3b70c5d878ec0d0dce6d10081b953e88fe9eddc0
Author: King Dix <kingdix10@xxxxxx>
Date:   Thu Jan 9 08:50:18 2025 +0800

    PCI: rcar-ep: Fix incorrect variable used when calling devm_request_mem_region()
    
    [ Upstream commit 2d2da5a4c1b4509f6f7e5a8db015cd420144beb4 ]
    
    The rcar_pcie_parse_outbound_ranges() uses the devm_request_mem_region()
    macro to request a needed resource. A string variable that lives on the
    stack is then used to store a dynamically computed resource name, which
    is then passed on as one of the macro arguments. This can lead to
    undefined behavior.
    
    Depending on the current contents of the memory, the manifestations of
    errors may vary. One possible output may be as follows:
    
      $ cat /proc/iomem
      30000000-37ffffff :
      38000000-3fffffff :
    
    Sometimes, garbage may appear after the colon.
    
    In very rare cases, if no NULL-terminator is found in memory, the system
    might crash because the string iterator will overrun which can lead to
    access of unmapped memory above the stack.
    
    Thus, fix this by replacing outbound_name with the name of the previously
    requested resource. With the changes applied, the output will be as
    follows:
    
      $ cat /proc/iomem
      30000000-37ffffff : memory2
      38000000-3fffffff : memory3
    
    Fixes: 2a6d0d63d999 ("PCI: rcar: Add endpoint mode support")
    Link: https://lore.kernel.org/r/tencent_DBDCC19D60F361119E76919ADAB25EC13C06@xxxxxx
    Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
    Signed-off-by: King Dix <kingdix10@xxxxxx>
    [kwilczynski: commit log]
    Signed-off-by: Krzysztof Wilczyński <kwilczynski@xxxxxxxxxx>
    Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
    Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/pci/controller/pcie-rcar-ep.c b/drivers/pci/controller/pcie-rcar-ep.c
index aa1cf24a5a723..c143ee1740ce7 100644
--- a/drivers/pci/controller/pcie-rcar-ep.c
+++ b/drivers/pci/controller/pcie-rcar-ep.c
@@ -110,7 +110,7 @@ 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;