Re: Potential null-pointer-dereference problem due to missing null-checking for ata_timing_find_mode
From: Damien Le Moal <hidden>
Date: 2021-10-24 23:24:41
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On 2021/10/25 3:08, YE Chengfeng wrote:
Hi, I found that the function *ata_timing_find_mode *could return a null pointer in some situattions, but some call sites of this function don't check whether the return value is a null pointer. Could it be a potential null-pointer-dereference problem? https://github.com/torvalds/linux/blob/master/drivers/ata/pata_acpi.c#L145 <https://github.com/torvalds/linux/blob/master/drivers/ata/pata_acpi.c#L145> <https://github.com/torvalds/linux/blob/master/drivers/ata/pata_acpi.c#L145> linux/pata_acpi.c at master · torvalds/linux <https://github.com/torvalds/linux/blob/master/drivers/ata/pata_acpi.c#L145> Linux kernel source tree. Contribute to torvalds/linux development by creating an account on GitHub. github.com Best Regards, - Chengfeng
The ata_timing array last element is 0xff, which is the initial value of pio/dma mode. So an entry will always be returned. I do not think the NULL return ever triggers. -- Damien Le Moal Western Digital Research