From 6900b9cc2cd3e66469a9561bb478b87c0903b0ea Mon Sep 17 00:00:00 2001 From: Marcus Cooper Date: Thu, 24 Jan 2019 13:43:39 +0100 Subject: systemd: Security fix CVE-2018-16864 Affects < v240 Signed-off-by: Marcus Cooper Signed-off-by: Richard Purdie --- ...-not-store-the-iovec-entry-for-process-co.patch | 204 +++++++++++++++++++++ meta/recipes-core/systemd/systemd_239.bb | 1 + 2 files changed, 205 insertions(+) create mode 100644 meta/recipes-core/systemd/systemd/0024-journald-do-not-store-the-iovec-entry-for-process-co.patch (limited to 'meta/recipes-core') diff --git a/meta/recipes-core/systemd/systemd/0024-journald-do-not-store-the-iovec-entry-for-process-co.patch b/meta/recipes-core/systemd/systemd/0024-journald-do-not-store-the-iovec-entry-for-process-co.patch new file mode 100644 index 0000000000..c3009545b1 --- /dev/null +++ b/meta/recipes-core/systemd/systemd/0024-journald-do-not-store-the-iovec-entry-for-process-co.patch @@ -0,0 +1,204 @@ +From fe19f5a9d0d8b9977e9507a9b66c3cc66744cd38 Mon Sep 17 00:00:00 2001 +From: =?UTF-8?q?Zbigniew=20J=C4=99drzejewski-Szmek?= +Date: Wed, 5 Dec 2018 18:38:39 +0100 +Subject: [PATCH] journald: do not store the iovec entry for process + commandline on stack + +This fixes a crash where we would read the commandline, whose length is under +control of the sending program, and then crash when trying to create a stack +allocation for it. + +CVE-2018-16864 +https://bugzilla.redhat.com/show_bug.cgi?id=1653855 + +The message actually doesn't get written to disk, because +journal_file_append_entry() returns -E2BIG. + +Patch backported from systemd master at +084eeb865ca63887098e0945fb4e93c852b91b0f. +--- + src/basic/io-util.c | 10 ++++++++++ + src/basic/io-util.h | 2 ++ + src/coredump/coredump.c | 31 +++++++++++-------------------- + src/journal/journald-server.c | 25 +++++++++++++++---------- + 4 files changed, 38 insertions(+), 30 deletions(-) + +diff --git a/src/basic/io-util.c b/src/basic/io-util.c +index 1f64cc933b..575398fbe6 100644 +--- a/src/basic/io-util.c ++++ b/src/basic/io-util.c +@@ -8,6 +8,7 @@ + #include + + #include "io-util.h" ++#include "string-util.h" + #include "time-util.h" + + int flush_fd(int fd) { +@@ -252,3 +253,12 @@ ssize_t sparse_write(int fd, const void *p, size_t sz, size_t run_length) { + + return q - (const uint8_t*) p; + } ++ ++char* set_iovec_string_field(struct iovec *iovec, size_t *n_iovec, const char *field, const char *value) { ++ char *x; ++ ++ x = strappend(field, value); ++ if (x) ++ iovec[(*n_iovec)++] = IOVEC_MAKE_STRING(x); ++ return x; ++} +diff --git a/src/basic/io-util.h b/src/basic/io-util.h +index ed189b5820..792a64ad5e 100644 +--- a/src/basic/io-util.h ++++ b/src/basic/io-util.h +@@ -71,3 +71,5 @@ static inline bool FILE_SIZE_VALID_OR_INFINITY(uint64_t l) { + #define IOVEC_MAKE(base, len) (struct iovec) IOVEC_INIT(base, len) + #define IOVEC_INIT_STRING(string) IOVEC_INIT((char*) string, strlen(string)) + #define IOVEC_MAKE_STRING(string) (struct iovec) IOVEC_INIT_STRING(string) ++ ++char* set_iovec_string_field(struct iovec *iovec, size_t *n_iovec, const char *field, const char *value); +diff --git a/src/coredump/coredump.c b/src/coredump/coredump.c +index 20a1cbdd45..18e4f61d72 100644 +--- a/src/coredump/coredump.c ++++ b/src/coredump/coredump.c +@@ -1053,19 +1053,10 @@ static int send_iovec(const struct iovec iovec[], size_t n_iovec, int input_fd) + return 0; + } + +-static char* set_iovec_field(struct iovec *iovec, size_t *n_iovec, const char *field, const char *value) { +- char *x; +- +- x = strappend(field, value); +- if (x) +- iovec[(*n_iovec)++] = IOVEC_MAKE_STRING(x); +- return x; +-} +- + static char* set_iovec_field_free(struct iovec *iovec, size_t *n_iovec, const char *field, char *value) { + char *x; + +- x = set_iovec_field(iovec, n_iovec, field, value); ++ x = set_iovec_string_field(iovec, n_iovec, field, value); + free(value); + return x; + } +@@ -1115,36 +1106,36 @@ static int gather_pid_metadata( + disable_coredumps(); + } + +- set_iovec_field(iovec, n_iovec, "COREDUMP_UNIT=", context[CONTEXT_UNIT]); ++ set_iovec_string_field(iovec, n_iovec, "COREDUMP_UNIT=", context[CONTEXT_UNIT]); + } + + if (cg_pid_get_user_unit(pid, &t) >= 0) + set_iovec_field_free(iovec, n_iovec, "COREDUMP_USER_UNIT=", t); + + /* The next few are mandatory */ +- if (!set_iovec_field(iovec, n_iovec, "COREDUMP_PID=", context[CONTEXT_PID])) ++ if (!set_iovec_string_field(iovec, n_iovec, "COREDUMP_PID=", context[CONTEXT_PID])) + return log_oom(); + +- if (!set_iovec_field(iovec, n_iovec, "COREDUMP_UID=", context[CONTEXT_UID])) ++ if (!set_iovec_string_field(iovec, n_iovec, "COREDUMP_UID=", context[CONTEXT_UID])) + return log_oom(); + +- if (!set_iovec_field(iovec, n_iovec, "COREDUMP_GID=", context[CONTEXT_GID])) ++ if (!set_iovec_string_field(iovec, n_iovec, "COREDUMP_GID=", context[CONTEXT_GID])) + return log_oom(); + +- if (!set_iovec_field(iovec, n_iovec, "COREDUMP_SIGNAL=", context[CONTEXT_SIGNAL])) ++ if (!set_iovec_string_field(iovec, n_iovec, "COREDUMP_SIGNAL=", context[CONTEXT_SIGNAL])) + return log_oom(); + +- if (!set_iovec_field(iovec, n_iovec, "COREDUMP_RLIMIT=", context[CONTEXT_RLIMIT])) ++ if (!set_iovec_string_field(iovec, n_iovec, "COREDUMP_RLIMIT=", context[CONTEXT_RLIMIT])) + return log_oom(); + +- if (!set_iovec_field(iovec, n_iovec, "COREDUMP_HOSTNAME=", context[CONTEXT_HOSTNAME])) ++ if (!set_iovec_string_field(iovec, n_iovec, "COREDUMP_HOSTNAME=", context[CONTEXT_HOSTNAME])) + return log_oom(); + +- if (!set_iovec_field(iovec, n_iovec, "COREDUMP_COMM=", context[CONTEXT_COMM])) ++ if (!set_iovec_string_field(iovec, n_iovec, "COREDUMP_COMM=", context[CONTEXT_COMM])) + return log_oom(); + + if (context[CONTEXT_EXE] && +- !set_iovec_field(iovec, n_iovec, "COREDUMP_EXE=", context[CONTEXT_EXE])) ++ !set_iovec_string_field(iovec, n_iovec, "COREDUMP_EXE=", context[CONTEXT_EXE])) + return log_oom(); + + if (sd_pid_get_session(pid, &t) >= 0) +@@ -1212,7 +1203,7 @@ static int gather_pid_metadata( + iovec[(*n_iovec)++] = IOVEC_MAKE_STRING(t); + + if (safe_atoi(context[CONTEXT_SIGNAL], &signo) >= 0 && SIGNAL_VALID(signo)) +- set_iovec_field(iovec, n_iovec, "COREDUMP_SIGNAL_NAME=SIG", signal_to_string(signo)); ++ set_iovec_string_field(iovec, n_iovec, "COREDUMP_SIGNAL_NAME=SIG", signal_to_string(signo)); + + return 0; /* we successfully acquired all metadata */ + } +diff --git a/src/journal/journald-server.c b/src/journal/journald-server.c +index 4f1550ec5b..31be085c6b 100644 +--- a/src/journal/journald-server.c ++++ b/src/journal/journald-server.c +@@ -753,6 +753,7 @@ static void dispatch_message_real( + pid_t object_pid) { + + char source_time[sizeof("_SOURCE_REALTIME_TIMESTAMP=") + DECIMAL_STR_MAX(usec_t)]; ++ _cleanup_free_ char *cmdline1 = NULL, *cmdline2 = NULL; + uid_t journal_uid; + ClientContext *o; + +@@ -769,20 +770,23 @@ static void dispatch_message_real( + IOVEC_ADD_NUMERIC_FIELD(iovec, n, c->uid, uid_t, uid_is_valid, UID_FMT, "_UID"); + IOVEC_ADD_NUMERIC_FIELD(iovec, n, c->gid, gid_t, gid_is_valid, GID_FMT, "_GID"); + +- IOVEC_ADD_STRING_FIELD(iovec, n, c->comm, "_COMM"); +- IOVEC_ADD_STRING_FIELD(iovec, n, c->exe, "_EXE"); +- IOVEC_ADD_STRING_FIELD(iovec, n, c->cmdline, "_CMDLINE"); +- IOVEC_ADD_STRING_FIELD(iovec, n, c->capeff, "_CAP_EFFECTIVE"); ++ IOVEC_ADD_STRING_FIELD(iovec, n, c->comm, "_COMM"); /* At most TASK_COMM_LENGTH (16 bytes) */ ++ IOVEC_ADD_STRING_FIELD(iovec, n, c->exe, "_EXE"); /* A path, so at most PATH_MAX (4096 bytes) */ + +- IOVEC_ADD_SIZED_FIELD(iovec, n, c->label, c->label_size, "_SELINUX_CONTEXT"); ++ if (c->cmdline) ++ /* At most _SC_ARG_MAX (2MB usually), which is too much to put on stack. ++ * Let's use a heap allocation for this one. */ ++ cmdline1 = set_iovec_string_field(iovec, &n, "_CMDLINE=", c->cmdline); + ++ IOVEC_ADD_STRING_FIELD(iovec, n, c->capeff, "_CAP_EFFECTIVE"); /* Read from /proc/.../status */ ++ IOVEC_ADD_SIZED_FIELD(iovec, n, c->label, c->label_size, "_SELINUX_CONTEXT"); + IOVEC_ADD_NUMERIC_FIELD(iovec, n, c->auditid, uint32_t, audit_session_is_valid, "%" PRIu32, "_AUDIT_SESSION"); + IOVEC_ADD_NUMERIC_FIELD(iovec, n, c->loginuid, uid_t, uid_is_valid, UID_FMT, "_AUDIT_LOGINUID"); + +- IOVEC_ADD_STRING_FIELD(iovec, n, c->cgroup, "_SYSTEMD_CGROUP"); ++ IOVEC_ADD_STRING_FIELD(iovec, n, c->cgroup, "_SYSTEMD_CGROUP"); /* A path */ + IOVEC_ADD_STRING_FIELD(iovec, n, c->session, "_SYSTEMD_SESSION"); + IOVEC_ADD_NUMERIC_FIELD(iovec, n, c->owner_uid, uid_t, uid_is_valid, UID_FMT, "_SYSTEMD_OWNER_UID"); +- IOVEC_ADD_STRING_FIELD(iovec, n, c->unit, "_SYSTEMD_UNIT"); ++ IOVEC_ADD_STRING_FIELD(iovec, n, c->unit, "_SYSTEMD_UNIT"); /* Unit names are bounded by UNIT_NAME_MAX */ + IOVEC_ADD_STRING_FIELD(iovec, n, c->user_unit, "_SYSTEMD_USER_UNIT"); + IOVEC_ADD_STRING_FIELD(iovec, n, c->slice, "_SYSTEMD_SLICE"); + IOVEC_ADD_STRING_FIELD(iovec, n, c->user_slice, "_SYSTEMD_USER_SLICE"); +@@ -803,13 +807,14 @@ static void dispatch_message_real( + IOVEC_ADD_NUMERIC_FIELD(iovec, n, o->uid, uid_t, uid_is_valid, UID_FMT, "OBJECT_UID"); + IOVEC_ADD_NUMERIC_FIELD(iovec, n, o->gid, gid_t, gid_is_valid, GID_FMT, "OBJECT_GID"); + ++ /* See above for size limits, only ->cmdline may be large, so use a heap allocation for it. */ + IOVEC_ADD_STRING_FIELD(iovec, n, o->comm, "OBJECT_COMM"); + IOVEC_ADD_STRING_FIELD(iovec, n, o->exe, "OBJECT_EXE"); +- IOVEC_ADD_STRING_FIELD(iovec, n, o->cmdline, "OBJECT_CMDLINE"); +- IOVEC_ADD_STRING_FIELD(iovec, n, o->capeff, "OBJECT_CAP_EFFECTIVE"); ++ if (o->cmdline) ++ cmdline2 = set_iovec_string_field(iovec, &n, "OBJECT_CMDLINE=", o->cmdline); + ++ IOVEC_ADD_STRING_FIELD(iovec, n, o->capeff, "OBJECT_CAP_EFFECTIVE"); + IOVEC_ADD_SIZED_FIELD(iovec, n, o->label, o->label_size, "OBJECT_SELINUX_CONTEXT"); +- + IOVEC_ADD_NUMERIC_FIELD(iovec, n, o->auditid, uint32_t, audit_session_is_valid, "%" PRIu32, "OBJECT_AUDIT_SESSION"); + IOVEC_ADD_NUMERIC_FIELD(iovec, n, o->loginuid, uid_t, uid_is_valid, UID_FMT, "OBJECT_AUDIT_LOGINUID"); + +-- +2.11.0 + diff --git a/meta/recipes-core/systemd/systemd_239.bb b/meta/recipes-core/systemd/systemd_239.bb index c146897508..94729a6a39 100644 --- a/meta/recipes-core/systemd/systemd_239.bb +++ b/meta/recipes-core/systemd/systemd_239.bb @@ -38,6 +38,7 @@ SRC_URI += "file://touchscreen.rules \ file://0001-sysctl-Don-t-pass-null-directive-argument-to-s.patch \ file://0002-core-Fix-use-after-free-case-in-load_from_path.patch \ file://0001-meson-rename-Ddebug-to-Ddebug-extra.patch \ + file://0024-journald-do-not-store-the-iovec-entry-for-process-co.patch \ " # patches made for musl are only applied on TCLIBC is musl -- cgit 1.2.3-korg