From: "Alex Bennée" <alex.bennee@linaro.org>
To: Vincent Fazio <vfazio@xes-inc.com>
Cc: qemu-trivial@nongnu.org, laurent@vivier.eu,
Vincent Fazio <vfazio@gmail.com>,
qemu-devel@nongnu.org
Subject: Re: [PATCH] linux-user/elfload: munmap proper address in pgd_find_hole_fallback
Date: Sun, 14 Feb 2021 11:32:54 +0000 [thread overview]
Message-ID: <87lfbqc2ab.fsf@linaro.org> (raw)
In-Reply-To: <20210131061849.12615-1-vfazio@xes-inc.com>
Vincent Fazio <vfazio@xes-inc.com> writes:
> From: Vincent Fazio <vfazio@gmail.com>
>
> Previously, if the build host's libc did not define MAP_FIXED_NOREPLACE
> or if the running kernel didn't support that flag, it was possible for
> pgd_find_hole_fallback to munmap an incorrect address which could lead to
> SIGSEGV if the range happened to overlap with the mapped address of the
> QEMU binary.
>
> mmap(0x1000, 22261224, PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_NORESERVE, -1, 0) = 0x7f889d331000
> munmap(0x1000, 22261224) = 0
> --- SIGSEGV {si_signo=SIGSEGV, si_code=SEGV_MAPERR, si_addr=0x84b817} ---
> ++ killed by SIGSEGV +++
>
> Now, always munmap the address returned by mmap.
>
> Fixes: 2667e069e7b5 ("linux-user: don't use MAP_FIXED in pgd_find_hole_fallback")
> Signed-off-by: Vincent Fazio <vfazio@gmail.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
--
Alex Bennée
next prev parent reply other threads:[~2021-02-14 11:34 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-31 6:18 [PATCH] linux-user/elfload: munmap proper address in pgd_find_hole_fallback Vincent Fazio
2021-02-13 21:37 ` Laurent Vivier
2021-02-14 11:32 ` Alex Bennée [this message]
2021-03-09 21:04 ` Vincent Fazio
2021-03-09 21:23 ` Laurent Vivier
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