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From: Khalid Aziz <khalid.aziz@oracle.com>
To: Michal Hocko <mhocko@kernel.org>, Kees Cook <keescook@chromium.org>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>,
	Michael Ellerman <mpe@ellerman.id.au>,
	"akpm@linux-foundation.org" <akpm@linux-foundation.org>,
	mm-commits@vger.kernel.org, LKML <linux-kernel@vger.kernel.org>,
	Linux-MM <linux-mm@kvack.org>,
	"linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>,
	Linux-Next <linux-next@vger.kernel.org>,
	Stephen Rothwell <sfr@canb.auug.org.au>,
	Mark Brown <broonie@kernel.org>,
	Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: [RFC PATCH] elf: enforce MAP_FIXED on overlaying elf segments (was: Re: ppc elf_map breakage with MAP_FIXED_NOREPLACE)
Date: Wed, 14 Feb 2018 09:30:18 -0700	[thread overview]
Message-ID: <1518625818.24026.2.camel@oracle.com> (raw)
In-Reply-To: <20180213100440.GM3443@dhcp22.suse.cz>

On Tue, 2018-02-13 at 11:04 +0100, Michal Hocko wrote:
> 
> From 97e7355a6dc31a73005fa806566a57eb5c38032b Mon Sep 17 00:00:00
> 2001
> From: Michal Hocko <mhocko@suse.com>
> Date: Tue, 13 Feb 2018 10:50:53 +0100
> Subject: [PATCH] elf: enforce MAP_FIXED on overlaying elf segments
> 
> Anshuman has reported that some ELF binaries in his environment fail
> to
> start with
>  [   23.423642] 9148 (sed): Uhuuh, elf segment at 0000000010030000
> requested but the memory is mapped already
>  [   23.423706] requested [10030000, 10040000] mapped [10030000,
> 10040000] 100073 anon
> 
> The reason is that the above binary has overlapping elf segments:
>   LOAD           0x0000000000000000 0x0000000010000000
> 0x0000000010000000
>                  0x0000000000013a8c 0x0000000000013a8c  R E    10000
>   LOAD           0x000000000001fd40 0x000000001002fd40
> 0x000000001002fd40
>                  0x00000000000002c0 0x00000000000005e8  RW     10000
>   LOAD           0x0000000000020328 0x0000000010030328
> 0x0000000010030328
>                  0x0000000000000384 0x00000000000094a0  RW     10000
> 
> That binary has two RW LOAD segments, the first crosses a page border
> into the second
> 
> 0x1002fd40 (LOAD2-vaddr) + 0x5e8 (LOAD2-memlen) == 0x10030328 (LOAD3-
> vaddr)
> 
> Handle this situation by enforcing MAP_FIXED when we establish a
> temporary brk VMA to handle overlapping segments. All other mappings
> will still use MAP_FIXED_NOREPLACE.
> 
> Fixes: fs, elf: drop MAP_FIXED usage from elf_map
> Reported-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
> Signed-off-by: Michal Hocko <mhocko@suse.com>
> ---
> 

Looks reasonable to me.

Reviewed-by: Khalid Aziz <khalid.aziz@oracle.com>

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  reply	other threads:[~2018-02-14 16:30 UTC|newest]

Thread overview: 40+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-01-05  0:20 mmotm 2018-01-04-16-19 uploaded akpm
2018-01-05  6:43 ` Anshuman Khandual
2018-01-05  8:46   ` Michal Hocko
2018-01-07  6:49     ` Anshuman Khandual
2018-01-07  9:02       ` ppc elf_map breakage with MAP_FIXED_NOREPLACE (was: Re: mmotm 2018-01-04-16-19 uploaded) Michal Hocko
2018-01-07 11:26         ` Michael Ellerman
2018-01-08  3:02           ` ppc elf_map breakage with MAP_FIXED_NOREPLACE Anshuman Khandual
2018-01-08 22:12             ` Michael Ellerman
2018-01-09 11:48               ` Anshuman Khandual
2018-01-09 16:13                 ` Michal Hocko
2018-01-11 10:08                   ` Anshuman Khandual
2018-01-17  8:07                     ` Michal Hocko
2018-01-23 11:25                       ` Anshuman Khandual
2018-01-23 12:45                         ` Michal Hocko
2018-01-23 15:58                           ` Anshuman Khandual
2018-01-23 16:06                             ` Michal Hocko
2018-01-24  5:09                               ` Anshuman Khandual
2018-01-24  9:05                                 ` Michal Hocko
2018-01-26 12:34                                   ` Anshuman Khandual
2018-01-26 14:04                                     ` Michal Hocko
2018-01-29  2:47                                       ` Anshuman Khandual
2018-01-29  5:32                                         ` Anshuman Khandual
2018-01-29 13:22                                           ` Michal Hocko
2018-01-30  3:35                                             ` Michael Ellerman
2018-01-30  9:42                                               ` Michal Hocko
2018-01-31  5:05                                                 ` Anshuman Khandual
2018-01-31 13:19                                                   ` Michal Hocko
2018-02-01  3:13                                                     ` Anshuman Khandual
2018-02-01 13:10                                                       ` Michal Hocko
2018-02-01 13:40                                                         ` Michal Hocko
2018-02-01 20:55                                                           ` Kees Cook
2018-02-13 10:04                                                             ` [RFC PATCH] elf: enforce MAP_FIXED on overlaying elf segments (was: Re: ppc elf_map breakage with MAP_FIXED_NOREPLACE) Michal Hocko
2018-02-14 16:30                                                               ` Khalid Aziz [this message]
2018-02-01 13:48                                                       ` ppc elf_map breakage with MAP_FIXED_NOREPLACE Michal Hocko
2018-02-01 21:06                                                         ` Kees Cook
2018-02-12 14:48                                                         ` Michal Hocko
2018-02-13  1:02                                                           ` Anshuman Khandual
2018-02-13  6:49                                                         ` Anshuman Khandual
2018-02-13 10:00                                                           ` Michal Hocko
2018-01-05 12:14   ` mmotm 2018-01-04-16-19 uploaded Michal Hocko

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