Hi Takashi,
Thanks for the swift reply.
On Wed, 30 Sep 2009 16:13:49 +0200, Takashi Iwai wrote:
At Wed, 30 Sep 2009 15:25:42 +0200, Jean Delvare wrote:
If i2c device probing fails, then there is no driver to dereference after calling i2c_new_device(). Stop assuming that probing will always succeed, to avoid NULL pointer dereferences. We have an easier access to the driver anyway.
Reported-by: Tim Shepard shep@alum.mit.edu Signed-off-by: Jean Delvare khali@linux-fr.org Cc: Johannes Berg johannes@sipsolutions.net
The code is similar to the one in therm_adt746x, for which Tim reported a real-world oops, so it should be fixed ASAP.
Jean, thanks for the patch.
I'm just wondering whether the additional NULL check of client->driver would be enough? If yes, sound/aoa/onyx.c has it, at least, and we can add the similar checks to the rest, too.
The NULL check of client->driver, if followed by a call to i2c_unregister_device(), would indeed be enough. But unlike the onyx driver which we know we sometimes load erroneously, the other drivers should never fail. I am reluctant to add code to handle error cases which are not supposed to happen, which is why I prefer my proposed fix: it does not add code.
That being said, I will be happy with any solution that fixes the problem, so if you prefer client->driver NULL checks, I can send a patch doing this.
Thanks,