linux-kernel - Re: [PATCH 2/2] ima: Free IMA measurement buffer after kexec syscall

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Message-ID: <87bldg1u3s.fsf@manicouagan.localdomain>
Date:   Fri, 22 Jan 2021 19:31:51 -0300
From:   Thiago Jung Bauermann <bauerman@...ux.ibm.com>
To:     Lakshmi Ramasubramanian <nramas@...ux.microsoft.com>
Cc:     zohar@...ux.ibm.com, dmitry.kasatkin@...il.com,
        ebiederm@...ssion.com, gregkh@...uxfoundation.org,
        sashal@...nel.org, tyhicks@...ux.microsoft.com,
        linux-integrity@...r.kernel.org, linux-kernel@...r.kernel.org,
        linuxppc-dev@...ts.ozlabs.org
Subject: Re: [PATCH 2/2] ima: Free IMA measurement buffer after kexec syscall


Lakshmi Ramasubramanian <nramas@...ux.microsoft.com> writes:

> IMA allocates kernel virtual memory to carry forward the measurement
> list, from the current kernel to the next kernel on kexec system call,
> in ima_add_kexec_buffer() function.  This buffer is not freed before
> completing the kexec system call resulting in memory leak.
>
> Add ima_buffer field in "struct kimage" to store the virtual address
> of the buffer allocated for the IMA measurement list.
> Free the memory allocated for the IMA measurement list in
> kimage_file_post_load_cleanup() function.
>
> Signed-off-by: Lakshmi Ramasubramanian <nramas@...ux.microsoft.com>
> Suggested-by: Tyler Hicks <tyhicks@...ux.microsoft.com>
> Fixes: 7b8589cc29e7 ("ima: on soft reboot, save the measurement list")

Good catch.

Reviewed-by: Thiago Jung Bauermann <bauerman@...ux.ibm.com>

-- 
Thiago Jung Bauermann
IBM Linux Technology Center