diff options
| -rw-r--r-- | pkg/seccomp/seccomp.go | 20 | ||||
| -rw-r--r-- | pkg/seccomp/seccomp_rules.go | 6 | ||||
| -rw-r--r-- | pkg/seccomp/seccomp_test.go | 27 |
3 files changed, 48 insertions, 5 deletions
diff --git a/pkg/seccomp/seccomp.go b/pkg/seccomp/seccomp.go index fc36efa23..55fd6967e 100644 --- a/pkg/seccomp/seccomp.go +++ b/pkg/seccomp/seccomp.go @@ -219,24 +219,36 @@ 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, seccompDataOffsetArgHigh(i)) + 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, seccompDataOffsetArgLow(i)) + 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 diff --git a/pkg/seccomp/seccomp_rules.go b/pkg/seccomp/seccomp_rules.go index 84c841d7f..06308cd29 100644 --- a/pkg/seccomp/seccomp_rules.go +++ b/pkg/seccomp/seccomp_rules.go @@ -62,7 +62,11 @@ func (a AllowValue) String() (s string) { // rule := Rule { // AllowValue(linux.ARCH_GET_FS | linux.ARCH_SET_FS), // arg0 // } -type Rule [6]interface{} +type Rule [7]interface{} // 6 arguments + RIP + +// RuleIP indicates what rules in the Rule array have to be applied to +// instruction pointer. +const RuleIP = 6 func (r Rule) String() (s string) { if len(r) == 0 { diff --git a/pkg/seccomp/seccomp_test.go b/pkg/seccomp/seccomp_test.go index abbee7051..da5a5e4b2 100644 --- a/pkg/seccomp/seccomp_test.go +++ b/pkg/seccomp/seccomp_test.go @@ -388,6 +388,33 @@ func TestBasic(t *testing.T) { }, }, }, + { + ruleSets: []RuleSet{ + { + Rules: SyscallRules{ + 1: []Rule{ + { + RuleIP: AllowValue(0x7aabbccdd), + }, + }, + }, + Action: linux.SECCOMP_RET_ALLOW, + }, + }, + defaultAction: linux.SECCOMP_RET_TRAP, + specs: []spec{ + { + desc: "IP: Syscall instruction pointer allowed", + data: seccompData{nr: 1, arch: linux.AUDIT_ARCH_X86_64, args: [6]uint64{}, instructionPointer: 0x7aabbccdd}, + want: linux.SECCOMP_RET_ALLOW, + }, + { + desc: "IP: Syscall instruction pointer disallowed", + data: seccompData{nr: 1, arch: linux.AUDIT_ARCH_X86_64, args: [6]uint64{}, instructionPointer: 0x711223344}, + want: linux.SECCOMP_RET_TRAP, + }, + }, + }, } { instrs, err := BuildProgram(test.ruleSets, test.defaultAction) if err != nil { |