Hi Bjorn,
On Fri, Oct 07, 2022 at 08:56:18AM +0200, Sascha Hauer wrote:
> When pci_create_attr() fails then pci_remove_resource_files() is called
> which will iterate over the res_attr[_wc] arrays and frees every non
> NULL entry. To avoid a double free here we have to set the failed entry
> to NULL in pci_create_attr() when freeing it.
>
> Fixes: b562ec8f74e4 ("PCI: Don't leak memory if sysfs_create_bin_file() fails")
> Signed-off-by: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
> Cc: <stable@xxxxxxxxxxxxxxx>
> ---
> drivers/pci/pci-sysfs.c | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
Any input to this one? There's this long unfixed race condition
described here:
https://patchwork.kernel.org/project/linux-pci/patch/20200716110423.xtfyb3n6tn5ixedh@pali/#23547255
And this patch at least prevents my system from crashing when this race
condition occurs.
Sascha
>
> diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
> index fc804e08e3cb5..a07381d46ddae 100644
> --- a/drivers/pci/pci-sysfs.c
> +++ b/drivers/pci/pci-sysfs.c
> @@ -1196,8 +1196,13 @@ static int pci_create_attr(struct pci_dev *pdev, int num, int write_combine)
> res_attr->size = pci_resource_len(pdev, num);
> res_attr->private = (void *)(unsigned long)num;
> retval = sysfs_create_bin_file(&pdev->dev.kobj, res_attr);
> - if (retval)
> + if (retval) {
> + if (write_combine)
> + pdev->res_attr_wc[num] = NULL;
> + else
> + pdev->res_attr[num] = NULL;
> kfree(res_attr);
> + }
>
> return retval;
> }
> --
> 2.30.2
>
>
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