From: Greg KH <greg@kroah.com>
To: Alexander Dahl <ada@thorsis.com>
Cc: stable@vger.kernel.org
Subject: Re: perf: Apply e9a6882f267a to v4.9 stable (fix for null-pointer dereference)
Date: Wed, 25 Nov 2020 12:48:39 +0100 [thread overview]
Message-ID: <X75El25Mf0FJcjLR@kroah.com> (raw)
In-Reply-To: <4431770.U1WXKbcAmY@ada>
On Wed, Nov 25, 2020 at 11:01:39AM +0100, Alexander Dahl wrote:
> Hei hei,
>
> please apply e9a6882f267a8105461066e3ea6b4b6b9be1b807 ("perf event: Check
> ref_reloc_sym before using it") to the v4.9 stable tree and maybe to later LTS
> trees (v4.14, v4.19) as well.
>
> That change is in mainline since v5.4-rc1 and it's a fix for a possible null
> pointer dereference in the tool 'perf', so it is a fix for a user space tool
> coming with the kernel tree actually.
>
> I am directly affeted by this, calling 'perf record' on an at91 based device
> (armv5te, sam9g20 soc) running PREEMPT RT kernel 4.9.220-rt143 results in a
> segfault here. I debugged this with gdb and tracked it down to the exact
> pointer being NULL, which is checked now in that above mentioned changeset.
>
> I could cleanly apply that changeset to my local tree and the segfault is not
> triggered anymore, I can use perf on that platform now.
>
> I only tested this on the above mentioned v4.9 based kernel version.
Now queued up, thanks.
greg k-h
prev parent reply other threads:[~2020-11-25 11:48 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-25 10:01 perf: Apply e9a6882f267a to v4.9 stable (fix for null-pointer dereference) Alexander Dahl
2020-11-25 11:48 ` Greg KH [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=X75El25Mf0FJcjLR@kroah.com \
--to=greg@kroah.com \
--cc=ada@thorsis.com \
--cc=stable@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.