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authorShin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>2022-06-01 19:51:59 +0900
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2022-06-10 15:53:12 +0200
commit928ea98252ad75118950941683893cf904541da9 (patch)
tree513a875e29ee2d55fd0a96954b3137d9f7247aec /drivers/bus
parent3ed8c7d39cfef831fe508fc1308f146912fa72e6 (diff)
downloadlinux-928ea98252ad75118950941683893cf904541da9.tar.bz2
bus: fsl-mc-bus: fix KASAN use-after-free in fsl_mc_bus_remove()
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>
Diffstat (limited to 'drivers/bus')
-rw-r--r--drivers/bus/fsl-mc/fsl-mc-bus.c6
1 files 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 e81a9700cfd0..6143dbf31f31 100644
--- a/drivers/bus/fsl-mc/fsl-mc-bus.c
+++ b/drivers/bus/fsl-mc/fsl-mc-bus.c
@@ -1239,14 +1239,14 @@ error_cleanup_mc_io:
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);
bus_unregister_notifier(&fsl_mc_bus_type, &fsl_mc_nb);