On Mon, May 13, 2013 at 11:32:18AM +0200, Arkadiusz Miskiewicz wrote: > Hi. > > This patch fixes a real problem on 3.8.x, .3.9.x. Possibly earlier stable > lines too but I only tested on 3.8 and 3.9. > > Upstream patch applies fine to 3.8 and 3.9 stable lines. > > Please add to the stable queue. Thanks.
I believe this is also applicable to the 3.5 kernel. I'm queuing it for this serie. Cheers, -- Luis > > commit 60403f7a4d9368d187f79cba5e4672d01df37574 Author: Guenter > Roeck <[email protected]> Date: Fri Apr 5 21:22:43 2013 -0700 > > watchdog: Fix race condition in registration code > > A race condition exists when registering the first watchdog device. > Sequence of events: > > - watchdog_register_device calls watchdog_dev_register > - watchdog_dev_register creates the watchdog misc device by calling > misc_register. > At that time, the matching character device (/dev/watchdog0) does not > yet > exist, and old_wdd is not set either. > - Userspace gets an event and opens /dev/watchdog > - watchdog_open is called and sets wdd = old_wdd, which is still NULL, > and tries to dereference it. This causes the kernel to panic. > > Seen with systemd trying to open /dev/watchdog immediately after > it was created. > > Reported-by: Arkadiusz Miskiewicz <[email protected]> > Signed-off-by: Guenter Roeck <[email protected]> > Tested-by: Arkadiusz Miskiewicz <[email protected]> > Signed-off-by: Wim Van Sebroeck <[email protected]> > > -- > Arkadiusz Miśkiewicz, arekm / maven.pl > -- > To unsubscribe from this list: send the line "unsubscribe stable" in > the body of a message to [email protected] > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
