Description

In the Linux kernel, the following vulnerability has been resolved: power: supply: bq27xxx: Fix poll_interval handling and races on remove Before this patch bq27xxx_battery_teardown() was setting poll_interval = 0 to avoid bq27xxx_battery_update() requeuing the delayed_work item. There are 2 problems with this: 1. If the driver is unbound through sysfs, rather then the module being rmmod-ed, this changes poll_interval unexpectedly 2. This is racy, after it being set poll_interval could be changed before bq27xxx_battery_update() checks it through /sys/module/bq27xxx_battery/parameters/poll_interval Fix this by added a removed attribute to struct bq27xxx_device_info and using that instead of setting poll_interval to 0. There also is another poll_interval related race on remove(), writing /sys/module/bq27xxx_battery/parameters/poll_interval will requeue the delayed_work item for all devices on the bq27xxx_battery_devices list and the device being removed was only removed from that list after cancelling the delayed_work item. Fix this by moving the removal from the bq27xxx_battery_devices list to before cancelling the delayed_work item.

References 8

• git.kernel.org https://git.kernel.org/stable/c/0c5f4cec759679c290720fbcf6bb81768e21c95b
• git.kernel.org https://git.kernel.org/stable/c/465d919151a1e8d40daf366b868914f59d073211
• git.kernel.org https://git.kernel.org/stable/c/4c9615474fb0a41cfad658d78db3c9ec70912969
• git.kernel.org https://git.kernel.org/stable/c/b12faeca0e819ea09051a705fef9df7ea7e9e18c
• git.kernel.org https://git.kernel.org/stable/c/c00bc80462afc7963f449d7f21d896d2f629cacc
• git.kernel.org https://git.kernel.org/stable/c/d952a1eaafcc5f0351caad5dbe9b5b3300d1d529
• git.kernel.org https://git.kernel.org/stable/c/e85757da9091998276ff21a13915ac25229cc232
• git.kernel.org https://git.kernel.org/stable/c/e98e5bebfcafc75a7b41192a607dfea5c1268afa

Remediation