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Re: [Qemu-devel] [PATCH v2] linux-user: return EINVAL from prctl(PR_*_SE
From: |
Riku Voipio |
Subject: |
Re: [Qemu-devel] [PATCH v2] linux-user: return EINVAL from prctl(PR_*_SECCOMP) |
Date: |
Mon, 6 Nov 2017 20:06:18 +0000 |
User-agent: |
Mutt/1.5.23 (2014-03-12) |
On Mon, Nov 06, 2017 at 06:03:51PM +0000, James Cowgill wrote:
> If an application tries to install a seccomp filter using
> prctl(PR_SET_SECCOMP), the filter is likely for the target instead of the host
> architecture. This will probably cause qemu to be immediately killed when it
> executes another syscall.
>
> Prevent this from happening by returning EINVAL from both seccomp prctl
> calls. This is the error returned by the kernel when seccomp support is
> disabled.
Thanks, applied to linux-user
> Fixes: https://bugs.launchpad.net/qemu/+bug/1726394
> Signed-off-by: James Cowgill <address@hidden>
> ---
> Changes from v1:
> - add comment
>
> linux-user/syscall.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/linux-user/syscall.c b/linux-user/syscall.c
> index d4497dec5d..419991e834 100644
> --- a/linux-user/syscall.c
> +++ b/linux-user/syscall.c
> @@ -10482,6 +10482,12 @@ abi_long do_syscall(void *cpu_env, int num, abi_long
> arg1,
> break;
> }
> #endif
> + case PR_GET_SECCOMP:
> + case PR_SET_SECCOMP:
> + /* Disable seccomp to prevent the target disabling syscalls we
> + * need. */
> + ret = -TARGET_EINVAL;
> + break;
> default:
> /* Most prctl options have no pointer arguments */
> ret = get_errno(prctl(arg1, arg2, arg3, arg4, arg5));
> --
> 2.15.0
>
>