teknoraver / rpms / systemd

Forked from rpms/systemd 2 months ago
Clone

Blame SOURCES/0169-bus-message-fix-calculation-of-offsets-table-for-arr.patch

ff6046
From 871bb5457c5951870d447f53c976a1a1f2dac85d Mon Sep 17 00:00:00 2001
ff6046
From: =?UTF-8?q?Zbigniew=20J=C4=99drzejewski-Szmek?= <zbyszek@in.waw.pl>
ff6046
Date: Fri, 3 Aug 2018 14:46:57 +0200
ff6046
Subject: [PATCH] bus-message: fix calculation of offsets table for arrays
ff6046
ff6046
This is similar to the grandparent commit 'fix calculation of offsets table',
ff6046
except that now the change is for array elements. Same story as before: we need
ff6046
to make sure that the offsets increase enough taking alignment into account.
ff6046
ff6046
While at it, rename 'p' to 'previous' to match similar code in other places.
ff6046
ff6046
(cherry picked from commit f88214cf9d66c93f4d22c4c8980de9ee3ff45bab)
ff6046
ff6046
Resolves: #1696224
ff6046
---
ff6046
 src/libsystemd/sd-bus/bus-message.c            |  17 ++++++++++++-----
ff6046
 ...sh-d8f3941c74219b4c03532c9b244d5ea539c61af5 | Bin 0 -> 41 bytes
ff6046
 2 files changed, 12 insertions(+), 5 deletions(-)
ff6046
 create mode 100644 test/fuzz/fuzz-bus-message/crash-d8f3941c74219b4c03532c9b244d5ea539c61af5
ff6046
ff6046
diff --git a/src/libsystemd/sd-bus/bus-message.c b/src/libsystemd/sd-bus/bus-message.c
ff6046
index c8f7937102..ac823aaf58 100644
ff6046
--- a/src/libsystemd/sd-bus/bus-message.c
ff6046
+++ b/src/libsystemd/sd-bus/bus-message.c
ff6046
@@ -3532,7 +3532,7 @@ static int bus_message_enter_array(
ff6046
 
ff6046
         size_t rindex;
ff6046
         void *q;
ff6046
-        int r, alignment;
ff6046
+        int r;
ff6046
 
ff6046
         assert(m);
ff6046
         assert(c);
ff6046
@@ -3558,6 +3558,7 @@ static int bus_message_enter_array(
ff6046
 
ff6046
         if (!BUS_MESSAGE_IS_GVARIANT(m)) {
ff6046
                 /* dbus1 */
ff6046
+                int alignment;
ff6046
 
ff6046
                 r = message_peek_body(m, &rindex, 4, 4, &q);
ff6046
                 if (r < 0)
ff6046
@@ -3591,7 +3592,8 @@ static int bus_message_enter_array(
ff6046
                 *n_offsets = 0;
ff6046
 
ff6046
         } else {
ff6046
-                size_t where, p = 0, framing, sz;
ff6046
+                size_t where, previous = 0, framing, sz;
ff6046
+                int alignment;
ff6046
                 unsigned i;
ff6046
 
ff6046
                 /* gvariant: variable length array */
ff6046
@@ -3619,17 +3621,22 @@ static int bus_message_enter_array(
ff6046
                 if (!*offsets)
ff6046
                         return -ENOMEM;
ff6046
 
ff6046
+                alignment = bus_gvariant_get_alignment(c->signature);
ff6046
+                assert(alignment > 0);
ff6046
+
ff6046
                 for (i = 0; i < *n_offsets; i++) {
ff6046
-                        size_t x;
ff6046
+                        size_t x, start;
ff6046
+
ff6046
+                        start = ALIGN_TO(previous, alignment);
ff6046
 
ff6046
                         x = bus_gvariant_read_word_le((uint8_t*) q + i * sz, sz);
ff6046
                         if (x > c->item_size - sz)
ff6046
                                 return -EBADMSG;
ff6046
-                        if (x < p)
ff6046
+                        if (x < start)
ff6046
                                 return -EBADMSG;
ff6046
 
ff6046
                         (*offsets)[i] = rindex + x;
ff6046
-                        p = x;
ff6046
+                        previous = x;
ff6046
                 }
ff6046
 
ff6046
                 *item_size = (*offsets)[0] - rindex;
ff6046
diff --git a/test/fuzz/fuzz-bus-message/crash-d8f3941c74219b4c03532c9b244d5ea539c61af5 b/test/fuzz/fuzz-bus-message/crash-d8f3941c74219b4c03532c9b244d5ea539c61af5
ff6046
new file mode 100644
ff6046
index 0000000000000000000000000000000000000000..26262e1149825a114a89bf9cee5aeca0be463984
ff6046
GIT binary patch
ff6046
literal 41
ff6046
rcmd1#|DTC5gMmSS0SHWtIT#p03
ff6046
ff6046
literal 0
ff6046
HcmV?d00001
ff6046