[systemd-commits] 2 commits - src/libudev

[Kay Sievers]

 src/libudev/libudev-enumerate.c |    5 +++++
 1 file changed, 5 insertions(+)

New commits:
commit 756c9a2499ca377b9e96ea6fc6911ff64040174e
Author: Kay Sievers <kay at vrfy.org>
Date:   Wed Sep 4 17:59:14 2013 +0200

    libudev: enumerate - do not try to match against an empty subsystem

diff --git a/src/libudev/libudev-enumerate.c b/src/libudev/libudev-enumerate.c
index 385829d..bc1e37d 100644
--- a/src/libudev/libudev-enumerate.c
+++ b/src/libudev/libudev-enumerate.c
@@ -721,12 +721,14 @@ static bool match_subsystem(struct udev_enumerate *udev_enumerate, const char *s
 {
         struct udev_list_entry *list_entry;
 
-        subsystem = subsystem ? : "";
+        if (!subsystem)
+                return false;
 
         udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_enumerate->subsystem_nomatch_list)) {
                 if (fnmatch(udev_list_entry_get_name(list_entry), subsystem, 0) == 0)
                         return false;
         }
+
         if (udev_list_get_entry(&udev_enumerate->subsystem_match_list) != NULL) {
                 udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_enumerate->subsystem_match_list)) {
                         if (fnmatch(udev_list_entry_get_name(list_entry), subsystem, 0) == 0)
@@ -734,6 +736,7 @@ static bool match_subsystem(struct udev_enumerate *udev_enumerate, const char *s
                 }
                 return false;
         }
+
         return true;
 }
 

commit f9e84da678cc28998fb04bf5ba326d91fc2850fa
Author: David Herrmann <dh.herrmann at gmail.com>
Date:   Fri Aug 30 15:50:41 2013 +0200

    libudev: enumerate: fix NULL-deref for subsystem-matches
    
    udev_device_get_subsystem() may return NULL if no subsystem could be
    figured out by libudev. This might be due to OOM or if the device
    disconnected between the udev_device_new() call and
    udev_device_get_subsystem(). Therefore, we need to handle subsystem==NULL
    safely.
    
    Instead of testing for it in each helper, we treat subsystem==NULL as
    empty subsystem in match_subsystem().
    
    Backtrace of udev_enumerate with an input-device disconnecting in exactly
    this time-frame:
     (gdb) bt
     #0  0x00007ffff569dc24 in strnlen () from /usr/lib/libc.so.6
     #1  0x00007ffff56d9e04 in fnmatch@@GLIBC_2.2.5 () from /usr/lib/libc.so.6
     #2  0x00007ffff5beb83d in match_subsystem (udev_enumerate=0x7a05f0, subsystem=0x0) at src/libudev/libudev-enumerate.c:727
     #3  0x00007ffff5bebb30 in parent_add_child (enumerate=enumerate at entry=0x7a05f0, path=<optimized out>) at src/libudev/libudev-enumerate.c:834
     #4  0x00007ffff5bebc3f in parent_crawl_children (enumerate=enumerate at entry=0x7a05f0, path=0x7a56b0 "/sys/devices/<shortened>/input/input97", maxdepth=maxdepth at entry=254) at src/libudev/libudev-enumerate.c:866
     #5  0x00007ffff5bebc54 in parent_crawl_children (enumerate=enumerate at entry=0x7a05f0, path=0x79e8c0 "/sys/devices/<shortened>/input", maxdepth=maxdepth at entry=255) at src/libudev/libudev-enumerate.c:868
     #6  0x00007ffff5bebc54 in parent_crawl_children (enumerate=enumerate at entry=0x7a05f0, path=path at entry=0x753190 "/sys/devices/<shortened>", maxdepth=maxdepth at entry=256) at src/libudev/libudev-enumerate.c:868
     #7  0x00007ffff5bec7df in scan_devices_children (enumerate=0x7a05f0) at src/libudev/libudev-enumerate.c:882
     #8  udev_enumerate_scan_devices (udev_enumerate=udev_enumerate at entry=0x7a05f0) at src/libudev/libudev-enumerate.c:919
     #9  0x00007ffff5df8777 in <random_caller> () at some/file.c:181

diff --git a/src/libudev/libudev-enumerate.c b/src/libudev/libudev-enumerate.c
index b96e5b2..385829d 100644
--- a/src/libudev/libudev-enumerate.c
+++ b/src/libudev/libudev-enumerate.c
@@ -721,6 +721,8 @@ static bool match_subsystem(struct udev_enumerate *udev_enumerate, const char *s
 {
         struct udev_list_entry *list_entry;
 
+        subsystem = subsystem ? : "";
+
         udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_enumerate->subsystem_nomatch_list)) {
                 if (fnmatch(udev_list_entry_get_name(list_entry), subsystem, 0) == 0)
                         return false;