diff options
Diffstat (limited to 'pkg')
| -rw-r--r-- | pkg/seccomp/seccomp.go | 17 | ||||
| -rw-r--r-- | pkg/seccomp/seccomp_rules.go | 3 | ||||
| -rw-r--r-- | pkg/seccomp/seccomp_test.go | 48 |
3 files changed, 68 insertions, 0 deletions
diff --git a/pkg/seccomp/seccomp.go b/pkg/seccomp/seccomp.go index c7503f2cc..fc36efa23 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) } @@ -223,6 +227,19 @@ func addSyscallArgsCheck(p *bpf.ProgramBuilder, rules []Rule, action linux.BPFAc p.AddStmt(bpf.Ld|bpf.Abs|bpf.W, seccompDataOffsetArgHigh(i)) p.AddJumpFalseLabel(bpf.Jmp|bpf.Jeq|bpf.K, high, 0, ruleViolationLabel(ruleSetIdx, sysno, ruleidx)) labelled = true + case GreaterThan: + 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.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.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)) } diff --git a/pkg/seccomp/seccomp_rules.go b/pkg/seccomp/seccomp_rules.go index 29eec8db1..84c841d7f 100644 --- a/pkg/seccomp/seccomp_rules.go +++ b/pkg/seccomp/seccomp_rules.go @@ -49,6 +49,9 @@ func (a AllowAny) String() (s string) { // AllowValue specifies a value that needs to be strictly matched. type AllowValue uintptr +// GreaterThan specifies a value that needs to be strictly smaller. +type GreaterThan uintptr + func (a AllowValue) String() (s string) { return fmt.Sprintf("%#x ", uintptr(a)) } diff --git a/pkg/seccomp/seccomp_test.go b/pkg/seccomp/seccomp_test.go index 353686ed3..abbee7051 100644 --- a/pkg/seccomp/seccomp_test.go +++ b/pkg/seccomp/seccomp_test.go @@ -340,6 +340,54 @@ func TestBasic(t *testing.T) { }, }, }, + { + ruleSets: []RuleSet{ + { + Rules: SyscallRules{ + 1: []Rule{ + { + GreaterThan(0xf), + GreaterThan(0xabcd000d), + }, + }, + }, + Action: linux.SECCOMP_RET_ALLOW, + }, + }, + defaultAction: linux.SECCOMP_RET_TRAP, + specs: []spec{ + { + desc: "GreaterThan: Syscall argument allowed", + data: seccompData{nr: 1, arch: linux.AUDIT_ARCH_X86_64, args: [6]uint64{0x10, 0xffffffff}}, + want: linux.SECCOMP_RET_ALLOW, + }, + { + desc: "GreaterThan: Syscall argument disallowed (equal)", + data: seccompData{nr: 1, arch: linux.AUDIT_ARCH_X86_64, args: [6]uint64{0xf, 0xffffffff}}, + want: linux.SECCOMP_RET_TRAP, + }, + { + desc: "Syscall argument disallowed (smaller)", + data: seccompData{nr: 1, arch: linux.AUDIT_ARCH_X86_64, args: [6]uint64{0x0, 0xffffffff}}, + want: linux.SECCOMP_RET_TRAP, + }, + { + desc: "GreaterThan2: Syscall argument allowed", + data: seccompData{nr: 1, arch: linux.AUDIT_ARCH_X86_64, args: [6]uint64{0x10, 0xfbcd000d}}, + want: linux.SECCOMP_RET_ALLOW, + }, + { + desc: "GreaterThan2: Syscall argument disallowed (equal)", + data: seccompData{nr: 1, arch: linux.AUDIT_ARCH_X86_64, args: [6]uint64{0x10, 0xabcd000d}}, + want: linux.SECCOMP_RET_TRAP, + }, + { + desc: "GreaterThan2: Syscall argument disallowed (smaller)", + data: seccompData{nr: 1, arch: linux.AUDIT_ARCH_X86_64, args: [6]uint64{0x10, 0xa000ffff}}, + want: linux.SECCOMP_RET_TRAP, + }, + }, + }, } { instrs, err := BuildProgram(test.ruleSets, test.defaultAction) if err != nil { |