public inbox for [email protected]
 help / color / mirror / Atom feed
From: Thomas Gleixner <[email protected]>
To: Ammar Faizi <[email protected]>, Borislav Petkov <[email protected]>
Cc: Ammar Faizi <[email protected]>,
	Alviro Iskandar Setiawan <[email protected]>,
	Dave Hansen <[email protected]>,
	"H. Peter Anvin" <[email protected]>, Ingo Molnar <[email protected]>,
	Tony Luck <[email protected]>,
	Yazen Ghannam <[email protected]>,
	Linux Edac Mailing List <[email protected]>,
	Linux Kernel Mailing List <[email protected]>,
	Stable Kernel <[email protected]>,
	GNU/Weeb Mailing List <[email protected]>,
	x86 Mailing List <[email protected]>
Subject: Re: [PATCH v6 2/2] x86/MCE/AMD: Fix memory leak when `threshold_create_bank()` fails
Date: Sun, 03 Apr 2022 19:03:58 +0200	[thread overview]
Message-ID: <87wng6ksjl.ffs@tglx> (raw)
In-Reply-To: <[email protected]>

On Tue, Mar 29 2022 at 17:47, Ammar Faizi wrote:

> In mce_threshold_create_device(), if threshold_create_bank() fails, the
> @bp will be leaked, because the call to mce_threshold_remove_device()
> will not free the @bp. mce_threshold_remove_device() frees
> @threshold_banks. At that point, the @bp has not been written to
> @threshold_banks, @threshold_banks is NULL, so the call is just a nop.
>
> Fix this by extracting the cleanup part into a new static function
> __threshold_remove_device(), then call it from create/remove device
> functions.

The way simpler fix is to move 

>  	}
>  	this_cpu_write(threshold_banks, bp);

before the loop. That's safe because the banks cannot yet be reached via
an MCE as the vector is not yet enabled:
  
>  	if (thresholding_irq_en)
>  		mce_threshold_vector = amd_threshold_interrupt;

Thanks,

        tglx

  reply	other threads:[~2022-04-03 17:04 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-03-29 10:47 [PATCH v6 0/2] Two x86 fixes Ammar Faizi
2022-03-29 10:47 ` [PATCH v6 1/2] x86/delay: Fix the wrong asm constraint in `delay_loop()` Ammar Faizi
2022-04-01 17:42   ` Dave Hansen
2022-04-02  5:15     ` Ammar Faizi
2022-04-03 16:57   ` Thomas Gleixner
2022-04-03 17:11     ` Ammar Faizi
2022-04-03 17:14     ` Thomas Gleixner
2022-04-05 20:50   ` [tip: x86/misc] x86/delay: Fix the wrong asm constraint in delay_loop() tip-bot2 for Ammar Faizi
2022-03-29 10:47 ` [PATCH v6 2/2] x86/MCE/AMD: Fix memory leak when `threshold_create_bank()` fails Ammar Faizi
2022-04-03 17:03   ` Thomas Gleixner [this message]
2022-04-03 17:43     ` Ammar Faizi
2022-04-03 17:45       ` Ammar Faizi
2022-04-03 18:46         ` Borislav Petkov
2022-04-05 20:56   ` [tip: ras/core] x86/MCE/AMD: Fix memory leak when threshold_create_bank() fails tip-bot2 for Ammar Faizi

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=87wng6ksjl.ffs@tglx \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    /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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox