From: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com> mainline inclusion from mainline-v5.19-rc3 commit 928ea98252ad75118950941683893cf904541da9 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IBP74W CVE: CVE-2022-49711 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- In fsl_mc_bus_remove(), mc->root_mc_bus_dev->mc_io is passed to fsl_destroy_mc_io(). However, mc->root_mc_bus_dev is already freed in fsl_mc_device_remove(). Then reference to mc->root_mc_bus_dev->mc_io triggers KASAN use-after-free. To avoid the use-after-free, keep the reference to mc->root_mc_bus_dev->mc_io in a local variable and pass to fsl_destroy_mc_io(). This patch needs rework to apply to kernels older than v5.15. Fixes: f93627146f0e ("staging: fsl-mc: fix asymmetry in destroy of mc_io") Cc: stable@vger.kernel.org # v5.15+ Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com> Link: https://lore.kernel.org/r/20220601105159.87752-1-shinichiro.kawasaki@wdc.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Tirui Yin <yintirui@huawei.com> Reviewed-by: yongqiang Liu <liuyongqiang13@huawei.com> --- drivers/bus/fsl-mc/fsl-mc-bus.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/bus/fsl-mc/fsl-mc-bus.c b/drivers/bus/fsl-mc/fsl-mc-bus.c index e329cdd7156c..5ffe7333a3c9 100644 --- a/drivers/bus/fsl-mc/fsl-mc-bus.c +++ b/drivers/bus/fsl-mc/fsl-mc-bus.c @@ -1080,14 +1080,14 @@ static int fsl_mc_bus_probe(struct platform_device *pdev) static int fsl_mc_bus_remove(struct platform_device *pdev) { struct fsl_mc *mc = platform_get_drvdata(pdev); + struct fsl_mc_io *mc_io; if (!fsl_mc_is_root_dprc(&mc->root_mc_bus_dev->dev)) return -EINVAL; + mc_io = mc->root_mc_bus_dev->mc_io; fsl_mc_device_remove(mc->root_mc_bus_dev); - - fsl_destroy_mc_io(mc->root_mc_bus_dev->mc_io); - mc->root_mc_bus_dev->mc_io = NULL; + fsl_destroy_mc_io(mc_io); return 0; } -- 2.22.0