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authorIan Lewis <ianmlewis@gmail.com>2020-08-17 21:44:31 -0400
committerIan Lewis <ianmlewis@gmail.com>2020-08-17 21:44:31 -0400
commitac324f646ee3cb7955b0b45a7453aeb9671cbdf1 (patch)
tree0cbc5018e8807421d701d190dc20525726c7ca76 /pkg/seccomp/seccomp.go
parent352ae1022ce19de28fc72e034cc469872ad79d06 (diff)
parent6d0c5803d557d453f15ac6f683697eeb46dab680 (diff)
Merge branch 'master' into ip-forwarding
- Merges aleksej-paschenko's with HEAD - Adds vfs2 support for ip_forward
Diffstat (limited to 'pkg/seccomp/seccomp.go')
-rw-r--r--pkg/seccomp/seccomp.go33
1 files changed, 31 insertions, 2 deletions
diff --git a/pkg/seccomp/seccomp.go b/pkg/seccomp/seccomp.go
index c7503f2cc..55fd6967e 100644
--- a/pkg/seccomp/seccomp.go
+++ b/pkg/seccomp/seccomp.go
@@ -199,6 +199,10 @@ func ruleViolationLabel(ruleSetIdx int, sysno uintptr, idx int) string {
return fmt.Sprintf("ruleViolation_%v_%v_%v", ruleSetIdx, sysno, idx)
}
+func ruleLabel(ruleSetIdx int, sysno uintptr, idx int, name string) string {
+ return fmt.Sprintf("rule_%v_%v_%v_%v", ruleSetIdx, sysno, idx, name)
+}
+
func checkArgsLabel(sysno uintptr) string {
return fmt.Sprintf("checkArgs_%v", sysno)
}
@@ -215,14 +219,39 @@ func addSyscallArgsCheck(p *bpf.ProgramBuilder, rules []Rule, action linux.BPFAc
switch a := arg.(type) {
case AllowAny:
case AllowValue:
+ dataOffsetLow := seccompDataOffsetArgLow(i)
+ dataOffsetHigh := seccompDataOffsetArgHigh(i)
+ if i == RuleIP {
+ dataOffsetLow = seccompDataOffsetIPLow
+ dataOffsetHigh = seccompDataOffsetIPHigh
+ }
high, low := uint32(a>>32), uint32(a)
// assert arg_low == low
- p.AddStmt(bpf.Ld|bpf.Abs|bpf.W, seccompDataOffsetArgLow(i))
+ p.AddStmt(bpf.Ld|bpf.Abs|bpf.W, dataOffsetLow)
p.AddJumpFalseLabel(bpf.Jmp|bpf.Jeq|bpf.K, low, 0, ruleViolationLabel(ruleSetIdx, sysno, ruleidx))
// assert arg_high == high
- p.AddStmt(bpf.Ld|bpf.Abs|bpf.W, seccompDataOffsetArgHigh(i))
+ p.AddStmt(bpf.Ld|bpf.Abs|bpf.W, dataOffsetHigh)
p.AddJumpFalseLabel(bpf.Jmp|bpf.Jeq|bpf.K, high, 0, ruleViolationLabel(ruleSetIdx, sysno, ruleidx))
labelled = true
+ case GreaterThan:
+ dataOffsetLow := seccompDataOffsetArgLow(i)
+ dataOffsetHigh := seccompDataOffsetArgHigh(i)
+ if i == RuleIP {
+ dataOffsetLow = seccompDataOffsetIPLow
+ dataOffsetHigh = seccompDataOffsetIPHigh
+ }
+ labelGood := fmt.Sprintf("gt%v", i)
+ high, low := uint32(a>>32), uint32(a)
+ // assert arg_high < high
+ p.AddStmt(bpf.Ld|bpf.Abs|bpf.W, dataOffsetHigh)
+ p.AddJumpFalseLabel(bpf.Jmp|bpf.Jge|bpf.K, high, 0, ruleViolationLabel(ruleSetIdx, sysno, ruleidx))
+ // arg_high > high
+ p.AddJumpFalseLabel(bpf.Jmp|bpf.Jeq|bpf.K, high, 0, ruleLabel(ruleSetIdx, sysno, ruleidx, labelGood))
+ // arg_low < low
+ p.AddStmt(bpf.Ld|bpf.Abs|bpf.W, dataOffsetLow)
+ p.AddJumpFalseLabel(bpf.Jmp|bpf.Jgt|bpf.K, low, 0, ruleViolationLabel(ruleSetIdx, sysno, ruleidx))
+ p.AddLabel(ruleLabel(ruleSetIdx, sysno, ruleidx, labelGood))
+ labelled = true
default:
return fmt.Errorf("unknown syscall rule type: %v", reflect.TypeOf(a))
}