Re: [PATCH v2 1/2] ima: Free IMA measurement buffer on error

On 2/5/21 9:49 AM, Mimi Zohar wrote:

Hi Mimi,

On Fri, 2021-02-05 at 09:39 -0800, Lakshmi Ramasubramanian wrote:

quoted

On 2/5/21 2:05 AM, Greg KH wrote:

quoted

On Thu, Feb 04, 2021 at 09:49:50AM -0800, Lakshmi Ramasubramanian wrote:

quoted

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.  In error code paths this memory
is not freed resulting in memory leak.

Free the memory allocated for the IMA measurement list in
the error code paths in ima_add_kexec_buffer() function.

Signed-off-by: Lakshmi Ramasubramanian <redacted>
Suggested-by: Tyler Hicks <redacted>
Fixes: 7b8589cc29e7 ("ima: on soft reboot, save the measurement list")
---
   security/integrity/ima/ima_kexec.c | 1 +
   1 file changed, 1 insertion(+)

<formletter>

This is not the correct way to submit patches for inclusion in the
stable kernel tree.  Please read:
      https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html
for how to do this properly.

</formletter>

Thanks for the info Greg.

I will re-submit the two patches in the proper format.

No need.  I'm testing these patches now.  I'm not exactly sure what the
problem is.  Stable wasn't Cc'ed.  Is it that you sent the patch
directly to Greg or added "Fixes"?

I had not Cced stable, but had "Fixes" tag in the patch.

Fixes: 7b8589cc29e7 ("ima: on soft reboot, save the measurement list")

The problem is that the buffer allocated for forwarding the IMA 
measurement list is not freed - at the end of the kexec call and also in 
an error path. Please see the patch description for

[PATCH v2 2/2] ima: Free IMA measurement buffer after kexec syscall

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.

thanks,
  -lakshmi