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SubjectRe: [PATCH] proc: Escape more characters in /proc/mounts output
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On 12/15/20 11:40 AM, Al Viro wrote:
> On Tue, Dec 15, 2020 at 09:54:54AM +0530, Siddhesh Poyarekar wrote:
>
>> + get_user(byte, (const char __user *)data);
>> +
>> + return byte ? strndup_user(data, PATH_MAX) : NULL;
>> }
>
> No. Not to mention anything else, you
> * fetch the same data twice
> * fail to check the get_user() results
>

Ahh sorry, I could inline the strndup_user call and put an additional
check for length == 1 to return NULL. Would that be acceptable?

The other alternative would be to not touch copy_mount_string and
instead, check after fetching the string and if it is blank, free it and
set to NULL. That seems more expensive though.

Siddhesh

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