diff options
Diffstat (limited to 'pkg/seccomp')
-rw-r--r-- | pkg/seccomp/BUILD | 4 | ||||
-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 | ||||
-rw-r--r-- | pkg/seccomp/seccomp_test_victim.go | 2 | ||||
-rw-r--r-- | pkg/seccomp/seccomp_unsafe.go | 2 |
6 files changed, 72 insertions, 4 deletions
diff --git a/pkg/seccomp/BUILD b/pkg/seccomp/BUILD index d1024e49d..af94e944d 100644 --- a/pkg/seccomp/BUILD +++ b/pkg/seccomp/BUILD @@ -1,5 +1,5 @@ -load("//tools/go_stateify:defs.bzl", "go_library", "go_test") -load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_embed_data") +load("//tools/go_stateify:defs.bzl", "go_library") +load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_embed_data", "go_test") package(licenses = ["notice"]) 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 { diff --git a/pkg/seccomp/seccomp_test_victim.go b/pkg/seccomp/seccomp_test_victim.go index 48413f1fb..da6b9eaaf 100644 --- a/pkg/seccomp/seccomp_test_victim.go +++ b/pkg/seccomp/seccomp_test_victim.go @@ -38,7 +38,7 @@ func main() { syscall.SYS_CLONE: {}, syscall.SYS_CLOSE: {}, syscall.SYS_DUP: {}, - syscall.SYS_DUP2: {}, + syscall.SYS_DUP3: {}, syscall.SYS_EPOLL_CREATE1: {}, syscall.SYS_EPOLL_CTL: {}, syscall.SYS_EPOLL_WAIT: {}, diff --git a/pkg/seccomp/seccomp_unsafe.go b/pkg/seccomp/seccomp_unsafe.go index 0a3d92854..be328db12 100644 --- a/pkg/seccomp/seccomp_unsafe.go +++ b/pkg/seccomp/seccomp_unsafe.go @@ -35,7 +35,7 @@ type sockFprog struct { //go:nosplit func SetFilter(instrs []linux.BPFInstruction) syscall.Errno { // PR_SET_NO_NEW_PRIVS is required in order to enable seccomp. See seccomp(2) for details. - if _, _, errno := syscall.RawSyscall(syscall.SYS_PRCTL, linux.PR_SET_NO_NEW_PRIVS, 1, 0); errno != 0 { + if _, _, errno := syscall.RawSyscall6(syscall.SYS_PRCTL, linux.PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0, 0); errno != 0 { return errno } |