From de29d8d415ab539195840aeba57a17cd6c89218f Mon Sep 17 00:00:00 2001
From: Jamie Liu <jamieliu@google.com>
Date: Thu, 8 Jul 2021 18:55:56 -0700
Subject: Fix some //pkg/seccomp bugs.
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- LockOSThread() around prctl(PR_SET_NO_NEW_PRIVS) => seccomp(). go:nosplit
"mostly" prevents async preemption, but IIUC preemption is still permitted
during function prologues:
funcpctab "".seccomp [valfunc=pctopcdata]
0 -1 00000 (gvisor/pkg/seccomp/seccomp_unsafe.go:110) TEXT "".seccomp(SB), NOSPLIT|ABIInternal, $72-32
0 00000 (gvisor/pkg/seccomp/seccomp_unsafe.go:110) TEXT "".seccomp(SB), NOSPLIT|ABIInternal, $72-32
0 -1 00000 (gvisor/pkg/seccomp/seccomp_unsafe.go:110) SUBQ $72, SP
4 00004 (gvisor/pkg/seccomp/seccomp_unsafe.go:110) MOVQ BP, 64(SP)
9 00009 (gvisor/pkg/seccomp/seccomp_unsafe.go:110) LEAQ 64(SP), BP
e 00014 (gvisor/pkg/seccomp/seccomp_unsafe.go:110) FUNCDATA $0, gclocals·ba30782f8935b28ed1adaec603e72627(SB)
e 00014 (gvisor/pkg/seccomp/seccomp_unsafe.go:110) FUNCDATA $1, gclocals·663f8c6bfa83aa777198789ce63d9ab4(SB)
e 00014 (gvisor/pkg/seccomp/seccomp_unsafe.go:110) FUNCDATA $2, "".seccomp.stkobj(SB)
e 00014 (gvisor/pkg/seccomp/seccomp_unsafe.go:111) PCDATA $0, $-2
e -2 00014 (gvisor/pkg/seccomp/seccomp_unsafe.go:111) MOVQ "".ptr+88(SP), AX
(-1 is objabi.PCDATA_UnsafePointSafe and -2 is objabi.PCDATA_UnsafePointUnsafe,
from Go's cmd/internal/objabi.)
- Handle non-errno failures from seccomp() with SECCOMP_FILTER_FLAG_TSYNC.
PiperOrigin-RevId: 383757580
---
pkg/sentry/platform/ptrace/subprocess_linux.go | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
(limited to 'pkg/sentry/platform')
diff --git a/pkg/sentry/platform/ptrace/subprocess_linux.go b/pkg/sentry/platform/ptrace/subprocess_linux.go
index 4f0260432..06a3bd340 100644
--- a/pkg/sentry/platform/ptrace/subprocess_linux.go
+++ b/pkg/sentry/platform/ptrace/subprocess_linux.go
@@ -181,7 +181,7 @@ func attachedThread(flags uintptr, defaultAction linux.BPFAction) (*thread, erro
// Set an aggressive BPF filter for the stub and all it's children. See
// the description of the BPF program built above.
- if errno := seccomp.SetFilter(instrs); errno != 0 {
+ if errno := seccomp.SetFilterInChild(instrs); errno != 0 {
unix.RawSyscall(unix.SYS_EXIT, uintptr(errno), 0, 0)
}
--
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