From: Stephen Smalley <sds@tycho.nsa.gov>
To: Ingo Molnar <mingo@kernel.org>
Cc: x86@kernel.org, linux-kernel@vger.kernel.org, keescook@chromium.org
Subject: Re: [PATCH v2] x86/mm: warn on W+x mappings
Date: Mon, 5 Oct 2015 15:13:44 -0400 [thread overview]
Message-ID: <5612CBE8.2010504@tycho.nsa.gov> (raw)
In-Reply-To: <20151003112701.GA4531@gmail.com>
On 10/03/2015 07:27 AM, Ingo Molnar wrote:
>
> * Stephen Smalley <sds@tycho.nsa.gov> wrote:
>
>> diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
>> index 30564e2..f8b1573 100644
>> --- a/arch/x86/mm/init_64.c
>> +++ b/arch/x86/mm/init_64.c
>> @@ -1150,6 +1150,8 @@ void mark_rodata_ro(void)
>> free_init_pages("unused kernel",
>> (unsigned long) __va(__pa_symbol(rodata_end)),
>> (unsigned long) __va(__pa_symbol(_sdata)));
>> +
>> + debug_checkwx();
>
> Any reason to not do this on NX capable 32-bit kernels as well?
Done in v3. However, I do see lots of W+X mappings there.
[ 1.012796] WARNING: CPU: 1 PID: 1 at arch/x86/mm/dump_pagetables.c:225 note_page+0x65d/0x840()
[ 1.012803] x86/mm: Found insecure W+X mapping at address f4a00000/0xf4a00000
[ 1.012805] Modules linked in:
[ 1.012833] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 4.3.0-rc4+ #2
[ 1.012837] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140709_153950- 04/01/2014
[ 1.012844] c0d32967 173b7da7 00000000 f7105e7c c0713490 f7105ebc f7105eac c045d077
[ 1.012848] c0c47ef8 f7105edc 00000001 c0c4de42 000000e1 c04551fd c04551fd f7105f3c
[ 1.012851] 00000002 00000000 f7105ec8 c045d0ee 00000009 f7105ebc c0c47ef8 f7105edc
[ 1.012855] Call Trace:
[ 1.012868] [<c0713490>] dump_stack+0x41/0x61
[ 1.012871] [<c045d077>] warn_slowpath_common+0x87/0xc0
[ 1.012873] [<c04551fd>] ? note_page+0x65d/0x840
[ 1.012875] [<c04551fd>] ? note_page+0x65d/0x840
[ 1.012877] [<c045d0ee>] warn_slowpath_fmt+0x3e/0x60
[ 1.012878] [<c04551fd>] note_page+0x65d/0x840
[ 1.012880] [<c04555b6>] ptdump_walk_pgd_level_core+0x1d6/0x2d0
[ 1.012883] [<c04557a6>] ptdump_walk_pgd_level_checkwx+0x16/0x20
[ 1.012886] [<c044ba15>] mark_rodata_ro+0x135/0x160
[ 1.012898] [<c0a9b33f>] kernel_init+0x1f/0xe0
[ 1.012906] [<c0484b41>] ? schedule_tail+0x11/0x50
[ 1.012909] [<c0aa0bc1>] ret_from_kernel_thread+0x21/0x30
[ 1.012910] [<c0a9b320>] ? rest_init+0x70/0x70
[ 1.012912] ---[ end trace 40a4f3d5e8fb70ac ]---
[ 1.012954] x86/mm: Checked W+X mappings: FAILED, 6556 W+X pages found.
next prev parent reply other threads:[~2015-10-05 19:14 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-02 19:29 [PATCH v2] x86/mm: warn on W+x mappings Stephen Smalley
2015-10-02 20:44 ` Kees Cook
2015-10-03 11:27 ` Ingo Molnar
2015-10-05 19:13 ` Stephen Smalley [this message]
2015-10-06 7:32 ` Ingo Molnar
2015-10-06 15:37 ` Stephen Smalley
2015-10-12 11:36 ` Borislav Petkov
2015-10-12 12:41 ` Matt Fleming
2015-10-12 12:49 ` Ingo Molnar
2015-10-12 12:55 ` Matt Fleming
2015-10-12 14:17 ` Ingo Molnar
2015-10-12 14:49 ` Matt Fleming
2015-10-12 15:34 ` Ard Biesheuvel
2015-10-12 15:50 ` Matt Fleming
2015-10-12 16:43 ` Ard Biesheuvel
2015-10-14 15:18 ` Ingo Molnar
2015-10-14 15:30 ` Andy Lutomirski
2015-10-14 15:35 ` Borislav Petkov
2015-10-15 10:10 ` Matt Fleming
2015-10-15 10:33 ` Borislav Petkov
2015-10-16 1:45 ` Ricardo Neri
2015-10-14 21:02 ` Matt Fleming
2015-10-21 9:42 ` Ingo Molnar
2015-10-21 12:49 ` Ingo Molnar
2015-10-21 12:57 ` Ard Biesheuvel
2015-10-21 13:24 ` Borislav Petkov
2015-10-21 13:28 ` Ard Biesheuvel
2015-10-21 14:36 ` Borislav Petkov
2015-10-21 18:46 ` Andy Lutomirski
2015-10-21 20:45 ` Matt Fleming
2015-10-21 20:49 ` Andy Lutomirski
2015-10-21 20:38 ` Matt Fleming
2015-10-12 14:56 ` Josh Triplett
2015-10-14 15:19 ` Ingo Molnar
2015-10-14 16:47 ` Josh Triplett
2015-10-21 9:43 ` Ingo Molnar
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