Re: [PATCH v3] Race between cat /proc/kallsyms and rmmod

[Paulo Marques]

Alexey Dobriyan wrote:
> Iterating code of /proc/kallsyms calls module_get_kallsym() which grabs
> and drops module_mutex internally and returns "struct module *",
> module is removed, aforementioned "struct module *" is used in non-trivial
> way.
>
> Steps to reproduce:
>
> 	modprobe/rmmod loop
> 	cat /proc/kallsyms >/dev/null loop
>
> Copy all needed info under module_mutex.
>
> NOTE: this patch keeps module_mutex static.

Yes, this patch fixes the "cat /proc/kallsyms" race without changing any 
"external" interfaces, so I think it should go into mainline in any case.

Acked-by: Paulo Marques <pmarques@xxxxxxxxxxxx>

--
Paulo Marques - www.grupopie.com

"All I ask is a chance to prove that money can't make me happy."
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/