Phase 6 (partial): --mitigate bridged for copy_fail_family

- copy_fail_family/iamroot_modules.c: two new bridge functions
  - copy_fail_family_mitigate: calls existing mitigate_apply() which
    blacklists algif_aead + esp4 + esp6 + rxrpc, sets
    kernel.apparmor_restrict_unprivileged_userns=1, drops caches.
  - copy_fail_family_cleanup: heuristic-routed cleanup. If the
    mitigation conf file (/etc/modprobe.d/dirtyfail-mitigations.conf)
    exists → mitigate_revert(). Otherwise → try_revert_passwd_page_cache()
    to evict /etc/passwd from page cache.
- All 5 copy_fail_family modules' .mitigate and .cleanup fields now
  point at these shared family-wide handlers (the mitigation is
  family-wide, not per-CVE).
- dirty_pipe and entrybleed: no --mitigate offered (no canonical
  patches / only-fix-is-upgrade). Documented in ROADMAP.

Verified end-to-end on kctf-mgr as non-root user:
  iamroot --mitigate copy_fail → 'mitigate requires root' (correct)
  iamroot --cleanup  copy_fail → 'no mitigation conf; evicting page cache'

CVES.md gains a per-module ops table; ROADMAP.md marks Phase 6 partial.
This commit is contained in:
2026-05-16 20:04:32 -04:00
parent 4943b82129
commit 28ad566964
3 changed files with 84 additions and 15 deletions
+54 -10
View File
@@ -24,6 +24,9 @@
#include "src/dirtyfrag_esp.h"
#include "src/dirtyfrag_esp6.h"
#include "src/dirtyfrag_rxrpc.h"
#include "src/mitigate.h"
#include <sys/stat.h>
static void apply_ctx(const struct iamroot_ctx *ctx)
{
@@ -34,6 +37,47 @@ static void apply_ctx(const struct iamroot_ctx *ctx)
* it's a debug knob; default stays off. */
}
/* ----- Family-wide --mitigate / --cleanup -----
*
* The family-wide mitigation (blacklist algif_aead + esp4 + esp6 + rxrpc,
* set apparmor_restrict_unprivileged_userns=1, drop_caches) is the same
* for every member of this family. All 5 modules' .mitigate fields
* therefore point at the same wrapper.
*
* For .cleanup we route based on visible state:
* - If the mitigation conf file is present, the user most recently
* ran --mitigate → revert that.
* - Otherwise the user ran --exploit → evict /etc/passwd from page
* cache.
* This is a heuristic, not a state machine. Sufficient for the common
* usage patterns. */
#define CFF_MITIGATE_CONF "/etc/modprobe.d/dirtyfail-mitigations.conf"
static iamroot_result_t copy_fail_family_mitigate(const struct iamroot_ctx *ctx)
{
apply_ctx(ctx);
return (iamroot_result_t)mitigate_apply();
}
static iamroot_result_t copy_fail_family_cleanup(const struct iamroot_ctx *ctx)
{
apply_ctx(ctx);
struct stat st;
if (stat(CFF_MITIGATE_CONF, &st) == 0) {
if (!ctx->json) {
fprintf(stderr, "[*] copy_fail_family: detected mitigation conf "
"(%s); reverting mitigation\n", CFF_MITIGATE_CONF);
}
return (iamroot_result_t)mitigate_revert();
}
if (!ctx->json) {
fprintf(stderr, "[*] copy_fail_family: no mitigation conf; "
"evicting /etc/passwd from page cache\n");
}
return try_revert_passwd_page_cache() ? IAMROOT_OK : IAMROOT_TEST_ERROR;
}
/* ----- copy_fail (CVE-2026-31431) ----- */
static iamroot_result_t copy_fail_detect_wrap(const struct iamroot_ctx *ctx)
@@ -91,8 +135,8 @@ const struct iamroot_module copy_fail_module = {
.kernel_range = "≤ 6.12.84, fixed mainline 2026-04-22",
.detect = copy_fail_detect_wrap,
.exploit = copy_fail_exploit_wrap,
.mitigate = NULL,
.cleanup = NULL,
.mitigate = copy_fail_family_mitigate,
.cleanup = copy_fail_family_cleanup,
.detect_auditd = copy_fail_family_auditd,
.detect_sigma = copy_fail_family_sigma,
.detect_yara = NULL,
@@ -121,8 +165,8 @@ const struct iamroot_module copy_fail_gcm_module = {
.kernel_range = "same as copy_fail; rfc4106(gcm(aes)) not in modprobe blacklist",
.detect = copy_fail_gcm_detect_wrap,
.exploit = copy_fail_gcm_exploit_wrap,
.mitigate = NULL,
.cleanup = NULL,
.mitigate = copy_fail_family_mitigate,
.cleanup = copy_fail_family_cleanup,
.detect_auditd = copy_fail_family_auditd,
.detect_sigma = copy_fail_family_sigma,
.detect_yara = NULL,
@@ -151,8 +195,8 @@ const struct iamroot_module dirty_frag_esp_module = {
.kernel_range = "same family as copy_fail; xfrm-ESP path",
.detect = dirty_frag_esp_detect_wrap,
.exploit = dirty_frag_esp_exploit_wrap,
.mitigate = NULL,
.cleanup = NULL,
.mitigate = copy_fail_family_mitigate,
.cleanup = copy_fail_family_cleanup,
.detect_auditd = copy_fail_family_auditd,
.detect_sigma = copy_fail_family_sigma,
.detect_yara = NULL,
@@ -181,8 +225,8 @@ const struct iamroot_module dirty_frag_esp6_module = {
.kernel_range = "same family as copy_fail; xfrm-ESP6 path; V6 STORE shift auto-calibrated",
.detect = dirty_frag_esp6_detect_wrap,
.exploit = dirty_frag_esp6_exploit_wrap,
.mitigate = NULL,
.cleanup = NULL,
.mitigate = copy_fail_family_mitigate,
.cleanup = copy_fail_family_cleanup,
.detect_auditd = copy_fail_family_auditd,
.detect_sigma = copy_fail_family_sigma,
.detect_yara = NULL,
@@ -211,8 +255,8 @@ const struct iamroot_module dirty_frag_rxrpc_module = {
.kernel_range = "kernels exposing AF_RXRPC + rxkad with fcrypt fallback",
.detect = dirty_frag_rxrpc_detect_wrap,
.exploit = dirty_frag_rxrpc_exploit_wrap,
.mitigate = NULL,
.cleanup = NULL,
.mitigate = copy_fail_family_mitigate,
.cleanup = copy_fail_family_cleanup,
.detect_auditd = copy_fail_family_auditd,
.detect_sigma = copy_fail_family_sigma,
.detect_yara = NULL,