From: Conor Dooley conor.dooley@microchip.com
Similar to commit 1c11289b34ab ("peci: cpu: Fix use-after-free in adev_release()"), the auxiliary device is not torn down in the correct order. If auxiliary_device_add() fails, the release callback will be called twice, resulting in a UAF. Due to timing, the auxdev code in this driver "took inspiration" from the aforementioned commit, and thus its bugs too!
Moving auxiliary_device_uninit() to the unregister callback instead avoids the issue.
CC: stable@vger.kernel.org Fixes: b56bae2dd6fd ("clk: microchip: mpfs: add reset controller") Signed-off-by: Conor Dooley conor.dooley@microchip.com --- Stephen, Claudiu is on leave at the moment, and although I can push stuff to the at-91 tree etc, it's probably simpler if you just take this yourself?
CC: Stephen Boyd sboyd@kernel.org CC: Conor Dooley conor.dooley@microchip.com CC: Daire McNamara daire.mcnamara@microchip.com CC: Michael Turquette mturquette@baylibre.com CC: Stephen Boyd sboyd@kernel.org CC: Claudiu Beznea claudiu.beznea@microchip.com CC: linux-clk@vger.kernel.org CC: linux-kernel@vger.kernel.org --- drivers/clk/microchip/clk-mpfs.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/clk/microchip/clk-mpfs.c b/drivers/clk/microchip/clk-mpfs.c index 4f0a19db7ed7..cc5d7dee59f0 100644 --- a/drivers/clk/microchip/clk-mpfs.c +++ b/drivers/clk/microchip/clk-mpfs.c @@ -374,14 +374,13 @@ static void mpfs_reset_unregister_adev(void *_adev) struct auxiliary_device *adev = _adev;
auxiliary_device_delete(adev); + auxiliary_device_uninit(adev); }
static void mpfs_reset_adev_release(struct device *dev) { struct auxiliary_device *adev = to_auxiliary_dev(dev);
- auxiliary_device_uninit(adev); - kfree(adev); }
Quoting Conor Dooley (2023-04-13 15:20:45)
From: Conor Dooley conor.dooley@microchip.com
Similar to commit 1c11289b34ab ("peci: cpu: Fix use-after-free in adev_release()"), the auxiliary device is not torn down in the correct order. If auxiliary_device_add() fails, the release callback will be called twice, resulting in a UAF. Due to timing, the auxdev code in this driver "took inspiration" from the aforementioned commit, and thus its bugs too!
Moving auxiliary_device_uninit() to the unregister callback instead avoids the issue.
CC: stable@vger.kernel.org Fixes: b56bae2dd6fd ("clk: microchip: mpfs: add reset controller") Signed-off-by: Conor Dooley conor.dooley@microchip.com
Applied to clk-next
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