Re: [PATCH v2] rpadlpar: fix potential drc_name corruption in store functions

From: Michael Ellerman
Date: Wed Mar 17 2021 - 08:24:58 EST


On Mon, 15 Mar 2021 15:48:21 -0600, Tyrel Datwyler wrote:
> Both add_slot_store() and remove_slot_store() try to fix up the drc_name
> copied from the store buffer by placing a NULL terminator at nbyte + 1
> or in place of a '\n' if present. However, the static buffer that we
> copy the drc_name data into is not zeored and can contain anything past
> the n-th byte. This is problematic if a '\n' byte appears in that buffer
> after nbytes and the string copied into the store buffer was not NULL
> terminated to start with as the strchr() search for a '\n' byte will mark
> this incorrectly as the end of the drc_name string resulting in a drc_name
> string that contains garbage data after the n-th byte. The following
> debugging shows an example of the drmgr utility writing "PHB 4543" to
> the add_slot sysfs attribute, but add_slot_store logging a corrupted
> string value.
>
> [...]

Applied to powerpc/fixes.

[1/1] rpadlpar: fix potential drc_name corruption in store functions
https://git.kernel.org/powerpc/c/cc7a0bb058b85ea03db87169c60c7cfdd5d34678

cheers