viacam: Don't explode if pci_find_bus() returns NULL
authorJesper Juhl <jj@chaosbits.net>
Mon, 1 Aug 2011 21:39:17 +0000 (23:39 +0200)
committerJiri Kosina <jkosina@suse.cz>
Thu, 15 Sep 2011 12:58:48 +0000 (14:58 +0200)
In the unlikely case that pci_find_bus() should return NULL
viacam_serial_is_enabled() is going to dereference a NULL pointer and
blow up. Better safe than sorry, so be defensive and check the
pointer.

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Acked-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
drivers/media/video/via-camera.c

index 85d3048c1d679dcc83cdf6a7afb8d0f6af1f15c2..bb7f17f2a33c20452ce9d6d37bbb29990215fe07 100644 (file)
@@ -1332,6 +1332,8 @@ static __devinit bool viacam_serial_is_enabled(void)
        struct pci_bus *pbus = pci_find_bus(0, 0);
        u8 cbyte;
 
+       if (!pbus)
+               return false;
        pci_bus_read_config_byte(pbus, VIACAM_SERIAL_DEVFN,
                        VIACAM_SERIAL_CREG, &cbyte);
        if ((cbyte & VIACAM_SERIAL_BIT) == 0)