This is a note to let you know that I've just added the patch titled ptp: free ptp device pin descriptors properly to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: ptp-free-ptp-device-pin-descriptors-properly.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit cff306c18d002a4a0ea187cae2115fc75d7f073a Author: Vladis Dronov <vdronov@xxxxxxxxxx> Date: Mon Jan 13 14:00:09 2020 +0100 ptp: free ptp device pin descriptors properly commit 75718584cb3c64e6269109d4d54f888ac5a5fd15 upstream. There is a bug in ptp_clock_unregister(), where ptp_cleanup_pin_groups() first frees ptp->pin_{,dev_}attr, but then posix_clock_unregister() needs them to destroy a related sysfs device. These functions can not be just swapped, as posix_clock_unregister() frees ptp which is needed in the ptp_cleanup_pin_groups(). Fix this by calling ptp_cleanup_pin_groups() in ptp_clock_release(), right before ptp is freed. This makes this patch fix an UAF bug in a patch which fixes an UAF bug. Reported-by: Antti Laakso <antti.laakso@xxxxxxxxx> Fixes: a33121e5487b ("ptp: fix the race between the release of ptp_clock and cdev") Link: https://lore.kernel.org/netdev/3d2bd09735dbdaf003585ca376b7c1e5b69a19bd.camel@xxxxxxxxx/ Signed-off-by: Vladis Dronov <vdronov@xxxxxxxxxx> Acked-by: Richard Cochran <richardcochran@xxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Ben Hutchings <ben.hutchings@xxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/ptp/ptp_clock.c b/drivers/ptp/ptp_clock.c index 977b52dbcbba2..efe68b13704d8 100644 --- a/drivers/ptp/ptp_clock.c +++ b/drivers/ptp/ptp_clock.c @@ -175,6 +175,7 @@ static void ptp_clock_release(struct device *dev) { struct ptp_clock *ptp = container_of(dev, struct ptp_clock, dev); + ptp_cleanup_pin_groups(ptp); mutex_destroy(&ptp->tsevq_mux); mutex_destroy(&ptp->pincfg_mux); ida_simple_remove(&ptp_clocks_map, ptp->index); @@ -275,9 +276,8 @@ int ptp_clock_unregister(struct ptp_clock *ptp) if (ptp->pps_source) pps_unregister_source(ptp->pps_source); - ptp_cleanup_pin_groups(ptp); - posix_clock_unregister(&ptp->clock); + return 0; } EXPORT_SYMBOL(ptp_clock_unregister);