From: Vladis Dronov vdronov@redhat.com
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@intel.com Fixes: a33121e5487b ("ptp: fix the race between the release of ptp_clock and cdev") Link: https://lore.kernel.org/netdev/3d2bd09735dbdaf003585ca376b7c1e5b69a19bd.came... Signed-off-by: Vladis Dronov vdronov@redhat.com Acked-by: Richard Cochran richardcochran@gmail.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Ben Hutchings ben.hutchings@codethink.co.uk Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/ptp/ptp_clock.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/ptp/ptp_clock.c b/drivers/ptp/ptp_clock.c index 2c1ae324da182..bf1536f1c90bb 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); @@ -276,9 +277,8 @@ 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);