As the possible failure of the devres_alloc(), the devm_ioremap() and
devm_ioport_map() may return NULL pointer.
And then, the 'base' and 'alt_base' is used in plat_ide_setup_ports().
Therefore, it should be better to add the check in order to avoid the
dereference of the NULL pointer.
Fixes: 2bfba3c444fe ("ide: remove useless subdirs from drivers/ide/")
Cc: 5.10
Signed-off-by: Jiasheng Jiang <[email protected]>
---
Changelog
v1 -> v2
* Change 1. Add cc.
---
drivers/ide/ide_platform.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/drivers/ide/ide_platform.c b/drivers/ide/ide_platform.c
index 91639fd6c276..8c6e1af7b6eb 100644
--- a/drivers/ide/ide_platform.c
+++ b/drivers/ide/ide_platform.c
@@ -85,6 +85,10 @@ static int plat_ide_probe(struct platform_device *pdev)
alt_base = devm_ioport_map(&pdev->dev,
res_alt->start, resource_size(res_alt));
}
+ if (!base || !alt_base) {
+ ret = -ENOMEM;
+ goto out;
+ }
memset(&hw, 0, sizeof(hw));
plat_ide_setup_ports(&hw, base, alt_base, pdata, res_irq->start);
--
2.25.1
On 1/7/22 16:04, Jiasheng Jiang wrote:
> As the possible failure of the devres_alloc(), the devm_ioremap() and
> devm_ioport_map() may return NULL pointer.
> And then, the 'base' and 'alt_base' is used in plat_ide_setup_ports().
> Therefore, it should be better to add the check in order to avoid the
> dereference of the NULL pointer.
>
> Fixes: 2bfba3c444fe ("ide: remove useless subdirs from drivers/ide/")
This patch only renamed files under drivers/ide. I do not think it is
the patch that introduced the problem you are trying to fix.
> Cc: 5.10
Please read
https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html?highlight=linux%20stable
> Signed-off-by: Jiasheng Jiang <[email protected]>
> ---
> Changelog
>
> v1 -> v2
>
> * Change 1. Add cc.
Adding a CC to the distribution list of the patch does not change the
patch itself, so no need for tagging "v2".
> ---
> drivers/ide/ide_platform.c | 4 ++++
Again, this file does NOT exist anymore.
The legacy IDE driver was removed from the kernel with version 5.14 by
commit b7fb14d3ac63 ("ide: remove the legacy ide driver"). libata now
implements drivers for legacy PATA/IDE drives. Have you checked first if
your fix is needed there ? If it is, then please send your patch against
the current libata tree. If the fix is needed only in older LTS kernels,
then please make that clear in a cover letter with your patch.
> 1 file changed, 4 insertions(+)
>
> diff --git a/drivers/ide/ide_platform.c b/drivers/ide/ide_platform.c
> index 91639fd6c276..8c6e1af7b6eb 100644
> --- a/drivers/ide/ide_platform.c
> +++ b/drivers/ide/ide_platform.c
> @@ -85,6 +85,10 @@ static int plat_ide_probe(struct platform_device *pdev)
> alt_base = devm_ioport_map(&pdev->dev,
> res_alt->start, resource_size(res_alt));
> }
> + if (!base || !alt_base) {
> + ret = -ENOMEM;
> + goto out;
> + }
>
> memset(&hw, 0, sizeof(hw));
> plat_ide_setup_ports(&hw, base, alt_base, pdata, res_irq->start);
--
Damien Le Moal
Western Digital Research
On Fri, Jan 07, 2022 at 05:28:59PM +0800, David Laight wrote:
> That !!alt_base doesn't look right.
> Without looking at the rest of the code maybe:
> if (!base && !alt_base)
> may be correct.
Thanks, that's my fault.
I will correct it.
> It also rather makes me wonder about the actual failure return value.
> If devm_ioport_map() returns a 'port number' for inb()/outb() then
> zero is technically a valid value!
That's not right.
The devm_ioport_map() returns NULL if fails and returns non-NULL
pointer if success.
And also we can find in `drivers/ata/pata_platform.c` that it also
use the same way to check the return value from devm_ioport_map().
I will submit a new version to correct my code.
Sincerely thanks,
Jiang