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gerrit.openbmc.org / openbmc / openbmc / f8caae304a2fa94cf2770b72a313ee843b2f177b / . / poky / meta / recipes-core / systemd / systemd / 0024-journald-do-not-store-the-iovec-entry-for-process-co.patch
blob: c2f78be39ef5ab7ad7833e65b59f0f471788efd7 [file] [log] [blame]
Brad Bishopf8caae32019-03-25 13:13:56 -0400[diff] [blame^]1From 9cb07e7d82c7c4f28bbaa1478e1387e8ea3d03dd Mon Sep 17 00:00:00 2001
Brad Bishop977dc1a2019-02-06 16:01:43 -0500[diff] [blame]2From: =?UTF-8?q?Zbigniew=20J=C4=99drzejewski-Szmek?= <zbyszek@in.waw.pl>
3Date: Wed, 5 Dec 2018 18:38:39 +0100
4Subject: [PATCH] journald: do not store the iovec entry for process
5 commandline on stack
6
7This fixes a crash where we would read the commandline, whose length is under
8control of the sending program, and then crash when trying to create a stack
9allocation for it.
10
11CVE-2018-16864
12https://bugzilla.redhat.com/show_bug.cgi?id=1653855
13
14The message actually doesn't get written to disk, because
15journal_file_append_entry() returns -E2BIG.
16
17Patch backported from systemd master at
18084eeb865ca63887098e0945fb4e93c852b91b0f.
Brad Bishopf8caae32019-03-25 13:13:56 -0400[diff] [blame^]19
20CVE: CVE-2018-16864
21Upstream-Status: Backport
22Signed-off-by: Marcus Cooper <marcusc@axis.com>
Brad Bishop977dc1a2019-02-06 16:01:43 -0500[diff] [blame]23---
24 src/basic/io-util.c | 10 ++++++++++
25 src/basic/io-util.h | 2 ++
26 src/coredump/coredump.c | 31 +++++++++++--------------------
27 src/journal/journald-server.c | 25 +++++++++++++++----------
28 4 files changed, 38 insertions(+), 30 deletions(-)
29
30diff --git a/src/basic/io-util.c b/src/basic/io-util.c
31index 1f64cc933b..575398fbe6 100644
32--- a/src/basic/io-util.c
33+++ b/src/basic/io-util.c
34@@ -8,6 +8,7 @@
35 #include <unistd.h>
36
37 #include "io-util.h"
38+#include "string-util.h"
39 #include "time-util.h"
40
41 int flush_fd(int fd) {
42@@ -252,3 +253,12 @@ ssize_t sparse_write(int fd, const void *p, size_t sz, size_t run_length) {
43
44 return q - (const uint8_t*) p;
45 }
46+
47+char* set_iovec_string_field(struct iovec *iovec, size_t *n_iovec, const char *field, const char *value) {
48+ char *x;
49+
50+ x = strappend(field, value);
51+ if (x)
52+ iovec[(*n_iovec)++] = IOVEC_MAKE_STRING(x);
53+ return x;
54+}
55diff --git a/src/basic/io-util.h b/src/basic/io-util.h
56index ed189b5820..792a64ad5e 100644
57--- a/src/basic/io-util.h
58+++ b/src/basic/io-util.h
59@@ -71,3 +71,5 @@ static inline bool FILE_SIZE_VALID_OR_INFINITY(uint64_t l) {
60 #define IOVEC_MAKE(base, len) (struct iovec) IOVEC_INIT(base, len)
61 #define IOVEC_INIT_STRING(string) IOVEC_INIT((char*) string, strlen(string))
62 #define IOVEC_MAKE_STRING(string) (struct iovec) IOVEC_INIT_STRING(string)
63+
64+char* set_iovec_string_field(struct iovec *iovec, size_t *n_iovec, const char *field, const char *value);
65diff --git a/src/coredump/coredump.c b/src/coredump/coredump.c
66index 20a1cbdd45..18e4f61d72 100644
67--- a/src/coredump/coredump.c
68+++ b/src/coredump/coredump.c
69@@ -1053,19 +1053,10 @@ static int send_iovec(const struct iovec iovec[], size_t n_iovec, int input_fd)
70 return 0;
71 }
72
73-static char* set_iovec_field(struct iovec *iovec, size_t *n_iovec, const char *field, const char *value) {
74- char *x;
75-
76- x = strappend(field, value);
77- if (x)
78- iovec[(*n_iovec)++] = IOVEC_MAKE_STRING(x);
79- return x;
80-}
81-
82 static char* set_iovec_field_free(struct iovec *iovec, size_t *n_iovec, const char *field, char *value) {
83 char *x;
84
85- x = set_iovec_field(iovec, n_iovec, field, value);
86+ x = set_iovec_string_field(iovec, n_iovec, field, value);
87 free(value);
88 return x;
89 }
90@@ -1115,36 +1106,36 @@ static int gather_pid_metadata(
91 disable_coredumps();
92 }
93
94- set_iovec_field(iovec, n_iovec, "COREDUMP_UNIT=", context[CONTEXT_UNIT]);
95+ set_iovec_string_field(iovec, n_iovec, "COREDUMP_UNIT=", context[CONTEXT_UNIT]);
96 }
97
98 if (cg_pid_get_user_unit(pid, &t) >= 0)
99 set_iovec_field_free(iovec, n_iovec, "COREDUMP_USER_UNIT=", t);
100
101 /* The next few are mandatory */
102- if (!set_iovec_field(iovec, n_iovec, "COREDUMP_PID=", context[CONTEXT_PID]))
103+ if (!set_iovec_string_field(iovec, n_iovec, "COREDUMP_PID=", context[CONTEXT_PID]))
104 return log_oom();
105
106- if (!set_iovec_field(iovec, n_iovec, "COREDUMP_UID=", context[CONTEXT_UID]))
107+ if (!set_iovec_string_field(iovec, n_iovec, "COREDUMP_UID=", context[CONTEXT_UID]))
108 return log_oom();
109
110- if (!set_iovec_field(iovec, n_iovec, "COREDUMP_GID=", context[CONTEXT_GID]))
111+ if (!set_iovec_string_field(iovec, n_iovec, "COREDUMP_GID=", context[CONTEXT_GID]))
112 return log_oom();
113
114- if (!set_iovec_field(iovec, n_iovec, "COREDUMP_SIGNAL=", context[CONTEXT_SIGNAL]))
115+ if (!set_iovec_string_field(iovec, n_iovec, "COREDUMP_SIGNAL=", context[CONTEXT_SIGNAL]))
116 return log_oom();
117
118- if (!set_iovec_field(iovec, n_iovec, "COREDUMP_RLIMIT=", context[CONTEXT_RLIMIT]))
119+ if (!set_iovec_string_field(iovec, n_iovec, "COREDUMP_RLIMIT=", context[CONTEXT_RLIMIT]))
120 return log_oom();
121
122- if (!set_iovec_field(iovec, n_iovec, "COREDUMP_HOSTNAME=", context[CONTEXT_HOSTNAME]))
123+ if (!set_iovec_string_field(iovec, n_iovec, "COREDUMP_HOSTNAME=", context[CONTEXT_HOSTNAME]))
124 return log_oom();
125
126- if (!set_iovec_field(iovec, n_iovec, "COREDUMP_COMM=", context[CONTEXT_COMM]))
127+ if (!set_iovec_string_field(iovec, n_iovec, "COREDUMP_COMM=", context[CONTEXT_COMM]))
128 return log_oom();
129
130 if (context[CONTEXT_EXE] &&
131- !set_iovec_field(iovec, n_iovec, "COREDUMP_EXE=", context[CONTEXT_EXE]))
132+ !set_iovec_string_field(iovec, n_iovec, "COREDUMP_EXE=", context[CONTEXT_EXE]))
133 return log_oom();
134
135 if (sd_pid_get_session(pid, &t) >= 0)
136@@ -1212,7 +1203,7 @@ static int gather_pid_metadata(
137 iovec[(*n_iovec)++] = IOVEC_MAKE_STRING(t);
138
139 if (safe_atoi(context[CONTEXT_SIGNAL], &signo) >= 0 && SIGNAL_VALID(signo))
140- set_iovec_field(iovec, n_iovec, "COREDUMP_SIGNAL_NAME=SIG", signal_to_string(signo));
141+ set_iovec_string_field(iovec, n_iovec, "COREDUMP_SIGNAL_NAME=SIG", signal_to_string(signo));
142
143 return 0; /* we successfully acquired all metadata */
144 }
145diff --git a/src/journal/journald-server.c b/src/journal/journald-server.c
146index 4f1550ec5b..31be085c6b 100644
147--- a/src/journal/journald-server.c
148+++ b/src/journal/journald-server.c
149@@ -753,6 +753,7 @@ static void dispatch_message_real(
150 pid_t object_pid) {
151
152 char source_time[sizeof("_SOURCE_REALTIME_TIMESTAMP=") + DECIMAL_STR_MAX(usec_t)];
153+ _cleanup_free_ char *cmdline1 = NULL, *cmdline2 = NULL;
154 uid_t journal_uid;
155 ClientContext *o;
156
157@@ -769,20 +770,23 @@ static void dispatch_message_real(
158 IOVEC_ADD_NUMERIC_FIELD(iovec, n, c->uid, uid_t, uid_is_valid, UID_FMT, "_UID");
159 IOVEC_ADD_NUMERIC_FIELD(iovec, n, c->gid, gid_t, gid_is_valid, GID_FMT, "_GID");
160
161- IOVEC_ADD_STRING_FIELD(iovec, n, c->comm, "_COMM");
162- IOVEC_ADD_STRING_FIELD(iovec, n, c->exe, "_EXE");
163- IOVEC_ADD_STRING_FIELD(iovec, n, c->cmdline, "_CMDLINE");
164- IOVEC_ADD_STRING_FIELD(iovec, n, c->capeff, "_CAP_EFFECTIVE");
165+ IOVEC_ADD_STRING_FIELD(iovec, n, c->comm, "_COMM"); /* At most TASK_COMM_LENGTH (16 bytes) */
166+ IOVEC_ADD_STRING_FIELD(iovec, n, c->exe, "_EXE"); /* A path, so at most PATH_MAX (4096 bytes) */
167
168- IOVEC_ADD_SIZED_FIELD(iovec, n, c->label, c->label_size, "_SELINUX_CONTEXT");
169+ if (c->cmdline)
170+ /* At most _SC_ARG_MAX (2MB usually), which is too much to put on stack.
171+ * Let's use a heap allocation for this one. */
172+ cmdline1 = set_iovec_string_field(iovec, &n, "_CMDLINE=", c->cmdline);
173
174+ IOVEC_ADD_STRING_FIELD(iovec, n, c->capeff, "_CAP_EFFECTIVE"); /* Read from /proc/.../status */
175+ IOVEC_ADD_SIZED_FIELD(iovec, n, c->label, c->label_size, "_SELINUX_CONTEXT");
176 IOVEC_ADD_NUMERIC_FIELD(iovec, n, c->auditid, uint32_t, audit_session_is_valid, "%" PRIu32, "_AUDIT_SESSION");
177 IOVEC_ADD_NUMERIC_FIELD(iovec, n, c->loginuid, uid_t, uid_is_valid, UID_FMT, "_AUDIT_LOGINUID");
178
179- IOVEC_ADD_STRING_FIELD(iovec, n, c->cgroup, "_SYSTEMD_CGROUP");
180+ IOVEC_ADD_STRING_FIELD(iovec, n, c->cgroup, "_SYSTEMD_CGROUP"); /* A path */
181 IOVEC_ADD_STRING_FIELD(iovec, n, c->session, "_SYSTEMD_SESSION");
182 IOVEC_ADD_NUMERIC_FIELD(iovec, n, c->owner_uid, uid_t, uid_is_valid, UID_FMT, "_SYSTEMD_OWNER_UID");
183- IOVEC_ADD_STRING_FIELD(iovec, n, c->unit, "_SYSTEMD_UNIT");
184+ IOVEC_ADD_STRING_FIELD(iovec, n, c->unit, "_SYSTEMD_UNIT"); /* Unit names are bounded by UNIT_NAME_MAX */
185 IOVEC_ADD_STRING_FIELD(iovec, n, c->user_unit, "_SYSTEMD_USER_UNIT");
186 IOVEC_ADD_STRING_FIELD(iovec, n, c->slice, "_SYSTEMD_SLICE");
187 IOVEC_ADD_STRING_FIELD(iovec, n, c->user_slice, "_SYSTEMD_USER_SLICE");
188@@ -803,13 +807,14 @@ static void dispatch_message_real(
189 IOVEC_ADD_NUMERIC_FIELD(iovec, n, o->uid, uid_t, uid_is_valid, UID_FMT, "OBJECT_UID");
190 IOVEC_ADD_NUMERIC_FIELD(iovec, n, o->gid, gid_t, gid_is_valid, GID_FMT, "OBJECT_GID");
191
192+ /* See above for size limits, only ->cmdline may be large, so use a heap allocation for it. */
193 IOVEC_ADD_STRING_FIELD(iovec, n, o->comm, "OBJECT_COMM");
194 IOVEC_ADD_STRING_FIELD(iovec, n, o->exe, "OBJECT_EXE");
195- IOVEC_ADD_STRING_FIELD(iovec, n, o->cmdline, "OBJECT_CMDLINE");
196- IOVEC_ADD_STRING_FIELD(iovec, n, o->capeff, "OBJECT_CAP_EFFECTIVE");
197+ if (o->cmdline)
198+ cmdline2 = set_iovec_string_field(iovec, &n, "OBJECT_CMDLINE=", o->cmdline);
199
200+ IOVEC_ADD_STRING_FIELD(iovec, n, o->capeff, "OBJECT_CAP_EFFECTIVE");
201 IOVEC_ADD_SIZED_FIELD(iovec, n, o->label, o->label_size, "OBJECT_SELINUX_CONTEXT");
202-
203 IOVEC_ADD_NUMERIC_FIELD(iovec, n, o->auditid, uint32_t, audit_session_is_valid, "%" PRIu32, "OBJECT_AUDIT_SESSION");
204 IOVEC_ADD_NUMERIC_FIELD(iovec, n, o->loginuid, uid_t, uid_is_valid, UID_FMT, "OBJECT_AUDIT_LOGINUID");
205
206--
2072.11.0
208