82 lines
3.1 KiB
Diff
82 lines
3.1 KiB
Diff
commit ebf61ed8471a45cf8bce7231de00cb1bbc140708
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Author: Martin Pitt <martin.pitt@ubuntu.com>
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Date: Wed Mar 5 14:07:44 2014 +0100
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Fix buffer overflow in mount path parsing
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In the mount monitor we parse mount points from /proc/self/mountinfo. Ensure
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that we don't overflow the buffers on platforms where mount paths could be
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longer than PATH_MAX (unknown if that can actually happen), as at least the
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mount paths for hotpluggable devices are somewhat user-controlled.
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Thanks to Florian Weimer for discovering this bug, and to David Zeuthen
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for his initial patch!
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CVE-2014-0004
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Index: udisks-1.0.4/src/mount-monitor.c
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===================================================================
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--- udisks-1.0.4.orig/src/mount-monitor.c 2011-08-25 20:27:33.000000000 +0200
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+++ udisks-1.0.4/src/mount-monitor.c 2014-03-10 13:38:18.309406561 +0100
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@@ -39,6 +39,11 @@
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#include "mount.h"
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#include "private.h"
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+/* build a %Ns format string macro with N == PATH_MAX */
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+#define xstr(s) str(s)
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+#define str(s) #s
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+#define PATH_MAX_FMT "%" xstr(PATH_MAX) "s"
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+
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/*--------------------------------------------------------------------------------------------------------------*/
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enum
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@@ -320,8 +325,8 @@ mount_monitor_ensure (MountMonitor *moni
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guint mount_id;
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guint parent_id;
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guint major, minor;
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- gchar encoded_root[PATH_MAX];
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- gchar encoded_mount_point[PATH_MAX];
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+ gchar encoded_root[PATH_MAX + 1];
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+ gchar encoded_mount_point[PATH_MAX + 1];
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gchar *mount_point;
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dev_t dev;
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@@ -329,7 +334,7 @@ mount_monitor_ensure (MountMonitor *moni
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continue;
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if (sscanf (lines[n],
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- "%d %d %d:%d %s %s",
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+ "%d %d %d:%d " PATH_MAX_FMT " " PATH_MAX_FMT,
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&mount_id,
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&parent_id,
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&major,
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@@ -340,6 +345,8 @@ mount_monitor_ensure (MountMonitor *moni
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g_warning ("Error parsing line '%s'", lines[n]);
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continue;
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}
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+ encoded_root[sizeof encoded_root - 1] = '\0';
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+ encoded_mount_point[sizeof encoded_mount_point - 1] = '\0';
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/* ignore mounts where only a subtree of a filesystem is mounted */
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if (g_strcmp0 (encoded_root, "/") != 0)
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@@ -358,15 +365,17 @@ mount_monitor_ensure (MountMonitor *moni
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sep = strstr (lines[n], " - ");
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if (sep != NULL)
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{
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- gchar fstype[PATH_MAX];
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- gchar mount_source[PATH_MAX];
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+ gchar fstype[PATH_MAX + 1];
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+ gchar mount_source[PATH_MAX + 1];
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struct stat statbuf;
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- if (sscanf (sep + 3, "%s %s", fstype, mount_source) != 2)
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+ if (sscanf (sep + 3, PATH_MAX_FMT " " PATH_MAX_FMT, fstype, mount_source) != 2)
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{
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g_warning ("Error parsing things past - for '%s'", lines[n]);
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continue;
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}
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+ fstype[sizeof fstype - 1] = '\0';
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+ mount_source[sizeof mount_source - 1] = '\0';
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if (g_strcmp0 (fstype, "btrfs") != 0)
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continue;
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