From: Vladis Dronov Date: Mon, 13 Jan 2020 13:00:09 +0000 (+0100) Subject: ptp: free ptp device pin descriptors properly X-Git-Tag: baikal/mips/sdk5.9~14532^2~30 X-Git-Url: https://git.baikalelectronics.ru/sdk/?a=commitdiff_plain;h=82f0446339901bb2b22717f5c12e21aa80ba8ba7;p=kernel.git ptp: free ptp device pin descriptors properly 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 Fixes: cfe094450df2 ("ptp: fix the race between the release of ptp_clock and cdev") Link: https://lore.kernel.org/netdev/3d2bd09735dbdaf003585ca376b7c1e5b69a19bd.camel@intel.com/ Signed-off-by: Vladis Dronov Acked-by: Richard Cochran Signed-off-by: David S. Miller --- diff --git a/drivers/ptp/ptp_clock.c b/drivers/ptp/ptp_clock.c index 61fafe0374cea..b84f16bbd6f24 100644 --- a/drivers/ptp/ptp_clock.c +++ b/drivers/ptp/ptp_clock.c @@ -170,6 +170,7 @@ 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); @@ -302,9 +303,8 @@ 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);