Messages in this thread Patch in this message | | | From | Sasha Levin <> | Subject | [PATCH AUTOSEL 4.19 34/56] ptp: free ptp device pin descriptors properly | Date | Fri, 24 Jan 2020 09:19:50 -0500 |
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From: Vladis Dronov <vdronov@redhat.com>
[ Upstream commit 75718584cb3c64e6269109d4d54f888ac5a5fd15 ]
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.camel@intel.com/ 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: 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 b818f65480c15..e232233beb8f2 100644 --- a/drivers/ptp/ptp_clock.c +++ b/drivers/ptp/ptp_clock.c @@ -179,6 +179,7 @@ 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); @@ -315,9 +316,8 @@ 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); -- 2.20.1
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