48 lines
1.8 KiB
Diff
48 lines
1.8 KiB
Diff
From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
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From: =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= <marcandre.lureau@redhat.com>
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Date: Wed, 22 Aug 2018 19:02:47 +0200
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Subject: [PATCH] seccomp: use SIGSYS signal instead of killing the thread
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MIME-Version: 1.0
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Content-Type: text/plain; charset=UTF-8
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Content-Transfer-Encoding: 8bit
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The seccomp action SCMP_ACT_KILL results in immediate termination of
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the thread that made the bad system call. However, qemu being
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multi-threaded, it keeps running. There is no easy way for parent
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process / management layer (libvirt) to know about that situation.
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Instead, the default SIGSYS handler when invoked with SCMP_ACT_TRAP
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will terminate the program and core dump.
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This may not be the most secure solution, but probably better than
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just killing the offending thread. SCMP_ACT_KILL_PROCESS has been
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added in Linux 4.14 to improve the situation, which I propose to use
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by default if available in the next patch.
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Related to:
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https://bugzilla.redhat.com/show_bug.cgi?id=1594456
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Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
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Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
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Acked-by: Eduardo Otubo <otubo@redhat.com>
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---
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qemu-seccomp.c | 2 +-
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1 file changed, 1 insertion(+), 1 deletion(-)
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diff --git a/qemu-seccomp.c b/qemu-seccomp.c
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index 9cd8eb9499..b117a92559 100644
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--- a/qemu-seccomp.c
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+++ b/qemu-seccomp.c
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@@ -125,7 +125,7 @@ static int seccomp_start(uint32_t seccomp_opts)
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continue;
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}
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- rc = seccomp_rule_add_array(ctx, SCMP_ACT_KILL, blacklist[i].num,
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+ rc = seccomp_rule_add_array(ctx, SCMP_ACT_TRAP, blacklist[i].num,
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blacklist[i].narg, blacklist[i].arg_cmp);
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if (rc < 0) {
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goto seccomp_return;
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--
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2.11.0
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