From 8ccebb04e07628f7fe10131d6cd4f19d6a0d8f45 Mon Sep 17 00:00:00 2001 From: Yu Watanabe Date: Wed, 8 Aug 2018 15:06:36 +0900 Subject: [PATCH] journal: fix syslog_parse_identifier() Fixes #9829. An out of bounds read was discovered in systemd-journald in the way it parses log messages that terminate with a colon ':'. A local attacker can use this flaw to disclose process memory data. Patch backported from systemd master at a6aadf4ae0bae185dc4c414d492a4a781c80ffe5. This matches the change done for systemd-journald, hence forming the first part of the fix for CVE-2018-16866. --- src/journal/journald-syslog.c | 6 +++--- src/journal/test-journal-syslog.c | 10 ++++++++-- 2 files changed, 11 insertions(+), 5 deletions(-) diff --git a/src/journal/journald-syslog.c b/src/journal/journald-syslog.c index 9dea116722..97711ac7a3 100644 --- a/src/journal/journald-syslog.c +++ b/src/journal/journald-syslog.c @@ -194,7 +194,7 @@ size_t syslog_parse_identifier(const char **buf, char **identifier, char **pid) e = l; l--; - if (p[l-1] == ']') { + if (l > 0 && p[l-1] == ']') { size_t k = l-1; for (;;) { @@ -219,8 +219,8 @@ size_t syslog_parse_identifier(const char **buf, char **identifier, char **pid) if (t) *identifier = t; - if (strchr(WHITESPACE, p[e])) - e++; + e += strspn(p + e, WHITESPACE); + *buf = p + e; return e; } diff --git a/src/journal/test-journal-syslog.c b/src/journal/test-journal-syslog.c index 9ba86f6c8a..05f759817e 100644 --- a/src/journal/test-journal-syslog.c +++ b/src/journal/test-journal-syslog.c @@ -5,8 +5,8 @@ #include "macro.h" #include "string-util.h" -static void test_syslog_parse_identifier(const char* str, - const char *ident, const char*pid, int ret) { +static void test_syslog_parse_identifier(const char *str, + const char *ident, const char *pid, int ret) { const char *buf = str; _cleanup_free_ char *ident2 = NULL, *pid2 = NULL; int ret2; @@ -21,7 +21,13 @@ static void test_syslog_parse_identifier(const char* str, int main(void) { test_syslog_parse_identifier("pidu[111]: xxx", "pidu", "111", 11); test_syslog_parse_identifier("pidu: xxx", "pidu", NULL, 6); + test_syslog_parse_identifier("pidu: xxx", "pidu", NULL, 7); test_syslog_parse_identifier("pidu xxx", NULL, NULL, 0); + test_syslog_parse_identifier(":", "", NULL, 1); + test_syslog_parse_identifier(": ", "", NULL, 3); + test_syslog_parse_identifier("pidu:", "pidu", NULL, 5); + test_syslog_parse_identifier("pidu: ", "pidu", NULL, 6); + test_syslog_parse_identifier("pidu : ", NULL, NULL, 0); return 0; } -- 2.11.0