linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Dave Hansen <dave.hansen@intel.com>
To: Paul Menzel <pmenzel@molgen.mpg.de>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	x86@kernel.org
Cc: LKML <linux-kernel@vger.kernel.org>
Subject: Re: kmemleak detects leak in msr_build_context
Date: Tue, 11 Jan 2022 07:26:31 -0800	[thread overview]
Message-ID: <cd46f836-7d81-2178-c5ab-64db0be17e0e@intel.com> (raw)
In-Reply-To: <94e48fcd-1dbd-ebd2-4c91-f39941735909@molgen.mpg.de>

On 1/10/22 23:49, Paul Menzel wrote:
> Running Linux from commit bf4eebf8cfa2 (Merge tag 
> 'linux-kselftest-kunit-5.17-rc1' of 
> git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest), 
> kmemleak reported the leak below:
> 
> ```
> unreferenced object 0xffff8914823de500 (size 64):
>    comm "swapper/0", pid 1, jiffies 4294667581 (age 1253.406s)
>    hex dump (first 32 bytes):
>      00 00 00 00 00 00 00 00 04 10 01 c0 00 00 00 00  ................
>      00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
>    backtrace:
>      [<000000007f3b05e9>] __kmalloc+0x177/0x330
>      [<0000000008104cca>] msr_build_context.constprop.0+0x32/0xbe
>      [<00000000012bab4e>] msr_save_cpuid_features+0x28/0x2f
>      [<00000000b7a2262e>] pm_check_save_msr+0x2e/0x40
>      [<00000000cbe9d92d>] do_one_initcall+0x44/0x200
>      [<0000000094deab7b>] kernel_init_freeable+0x1fc/0x273
>      [<00000000d3dbaa56>] kernel_init+0x16/0x160
>      [<0000000058c4a8b3>] ret_from_fork+0x22/0x30

Thanks for the report.

I've taken a look through arch/x86/power/cpu.c, and nothing obvious 
jumped out at me.  msr_build_context() could probably be cleaned up by 
using kvrealloc(), but it hasn't been touched recently in a way that I 
would expect things to leak.

I suspect this is a false positive from kmemleak.

If you could share your full dmesg, it might help spot something.  But, 
I didn't see anything.

  reply	other threads:[~2022-01-11 15:26 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-01-11  7:49 kmemleak detects leak in msr_build_context Paul Menzel
2022-01-11 15:26 ` Dave Hansen [this message]
2022-01-11 21:05   ` Paul Menzel
2022-01-11 23:16     ` Borislav Petkov
2022-01-14 11:09       ` Catalin Marinas
2022-01-14 11:44     ` Catalin Marinas

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=cd46f836-7d81-2178-c5ab-64db0be17e0e@intel.com \
    --to=dave.hansen@intel.com \
    --cc=bp@alien8.de \
    --cc=dave.hansen@linux.intel.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@redhat.com \
    --cc=pmenzel@molgen.mpg.de \
    --cc=tglx@linutronix.de \
    --cc=x86@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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).