From da3750f981fc889f5785d8185d7ac1e8a55a32c2 Mon Sep 17 00:00:00 2001 From: James M Snell Date: Wed, 3 Feb 2016 19:09:52 -0800 Subject: [PATCH] src: add --security-revert command line flag The `--security-revert={cvenum}` command line flag is a special purpose flag to be used only in stable or LTS branches when a breaking change is required to address a security vulnerability. Whenever a vulnerability requires a breaking change, and a CVE has been assigned, the flag can be used to force Node to revert to the insecure behavior that was implemented before the fix was applied. Note that this flag is intended to be used only as a last resort in the case a security update breaks existing code. When used, a security warning will be printed to stderr when Node launches. The `--security-revert={cvenum}` flag takes a single CVE number as an argument. Multiple instances of the `--security-revert={cvenum}` flag can be used on the command line to revert multiple changes. Whenever a new `--security-revert={cvenum}` is enabled, it should be documented in the release notes and in the API docs. Master and the first release of a new major (e.g. v6.0) should not have any reverts available. Every time a new `--security-revert={cvenum}` is added, there should be a semver-minor bump in the stable and LTS branch. PR-URL: https://github.com/nodejs/node-private/pull/20 --- node.gyp | 2 ++ src/node.cc | 14 ++++++++++++ src/node_revert.cc | 53 ++++++++++++++++++++++++++++++++++++++++++++++ src/node_revert.h | 43 +++++++++++++++++++++++++++++++++++++ 4 files changed, 112 insertions(+) create mode 100644 src/node_revert.cc create mode 100644 src/node_revert.h diff --git a/node.gyp b/node.gyp index 778162119a0006..720d51946976b2 100644 --- a/node.gyp +++ b/node.gyp @@ -117,6 +117,7 @@ 'src/node_javascript.cc', 'src/node_main.cc', 'src/node_os.cc', + 'src/node_revert.cc', 'src/node_util.cc', 'src/node_v8.cc', 'src/node_stat_watcher.cc', @@ -156,6 +157,7 @@ 'src/node_version.h', 'src/node_watchdog.h', 'src/node_wrap.h', + 'src/node_revert.h', 'src/node_i18n.h', 'src/pipe_wrap.h', 'src/tty_wrap.h', diff --git a/src/node.cc b/src/node.cc index 65afc8c1fe02f2..830ff8b0106620 100644 --- a/src/node.cc +++ b/src/node.cc @@ -6,6 +6,7 @@ #include "node_javascript.h" #include "node_version.h" #include "node_internals.h" +#include "node_revert.h" #if defined HAVE_PERFCTR #include "node_counters.h" @@ -2976,6 +2977,16 @@ void SetupProcessObject(Environment* env, READONLY_PROPERTY(process, "traceDeprecation", True(env->isolate())); } + // --security-revert flags +#define V(code, _, __) \ + do { \ + if (IsReverted(REVERT_ ## code)) { \ + READONLY_PROPERTY(process, "REVERT_" #code, True(env->isolate())); \ + } \ + } while (0); + REVERSIONS(V) +#undef V + size_t exec_path_len = 2 * PATH_MAX; char* exec_path = new char[exec_path_len]; Local exec_path_value; @@ -3339,6 +3350,9 @@ static void ParseArgs(int* argc, track_heap_objects = true; } else if (strcmp(arg, "--throw-deprecation") == 0) { throw_deprecation = true; + } else if (strncmp(arg, "--security-revert=", 18) == 0) { + const char* cve = arg + 18; + Revert(cve); } else if (strcmp(arg, "--v8-options") == 0) { new_v8_argv[new_v8_argc] = "--help"; new_v8_argc += 1; diff --git a/src/node_revert.cc b/src/node_revert.cc new file mode 100644 index 00000000000000..7a4f59d0cdedcd --- /dev/null +++ b/src/node_revert.cc @@ -0,0 +1,53 @@ +#include "node_revert.h" +#include +#include + +namespace node { + +unsigned int reverted = 0; + +const char* RevertMessage(const unsigned int cve) { +#define V(code, label, msg) case REVERT_ ## code: return label ": " msg; + switch (cve) { + REVERSIONS(V) + default: + return "Unknown"; + } +#undef V +} + +void Revert(const unsigned int cve) { + reverted |= 1 << cve; + printf("SECURITY WARNING: Reverting %s\n", RevertMessage(cve)); +} + +void Revert(const char* cve) { +#define V(code, label, _) \ + do { \ + if (strcmp(cve, label) == 0) { \ + Revert(REVERT_ ## code); \ + return; \ + } \ + } while (0); + REVERSIONS(V) +#undef V + printf("Error: Attempt to revert an unknown CVE [%s]\n", cve); + exit(12); +} + +bool IsReverted(const unsigned int cve) { + return reverted & (1 << cve); +} + +bool IsReverted(const char * cve) { +#define V(code, label, _) \ + do { \ + if (strcmp(cve, label) == 0) \ + return IsReverted(REVERT_ ## code); \ + } while (0); + REVERSIONS(V) + return false; +#undef V +} + +} // namespace node diff --git a/src/node_revert.h b/src/node_revert.h new file mode 100644 index 00000000000000..7a779ff4962e60 --- /dev/null +++ b/src/node_revert.h @@ -0,0 +1,43 @@ +#ifndef SRC_NODE_REVERT_H_ +#define SRC_NODE_REVERT_H_ + +#include "node.h" + +/** + * Note that it is expected for this list to vary across specific LTS and + * Stable versions! Only CVE's whose fixes require *breaking* changes within + * a given LTS or Stable may be added to this list, and only with CTC + * consensus. + * + * For *master* this list should always be empty! + * + **/ +#define REVERSIONS(XX) +// XX(CVE_2016_PEND, "CVE-2016-PEND", "Vulnerability Title") + +namespace node { + +typedef enum { +#define V(code, _, __) REVERT_ ## code, + REVERSIONS(V) +#undef V +} reversions_t; + +/* A bit field for tracking the active reverts */ +extern unsigned int reverted; + +/* Revert the given CVE (see reversions_t enum) */ +void Revert(const unsigned int cve); + +/* Revert the given CVE by label */ +void Revert(const char* cve); + +/* true if the CVE has been reverted **/ +bool IsReverted(const unsigned int cve); + +/* true if the CVE has been reverted **/ +bool IsReverted(const char * cve); + +} // namespace node + +#endif // SRC_NODE_REVERT_H_