From a66f1efcf748febea7758c4c3c8b5bc5294949ef Mon Sep 17 00:00:00 2001 From: Rob Clark Date: Tue, 10 Jan 2023 13:28:59 -0800 Subject: drm/msm/gpu: Fix potential double-free If userspace was calling the MSM_SET_PARAM ioctl on multiple threads to set the COMM or CMDLINE param, it could trigger a race causing the previous value to be kfree'd multiple times. Fix this by serializing on the gpu lock. Signed-off-by: Rob Clark Fixes: d4726d770068 ("drm/msm: Add a way to override processes comm/cmdline") Patchwork: https://patchwork.freedesktop.org/patch/517778/ Link: https://lore.kernel.org/r/20230110212903.1925878-1-robdclark@gmail.com --- drivers/gpu/drm/msm/msm_gpu.h | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) (limited to 'drivers/gpu/drm/msm/msm_gpu.h') diff --git a/drivers/gpu/drm/msm/msm_gpu.h b/drivers/gpu/drm/msm/msm_gpu.h index 58a72e6b1400..a89bfdc3d7f9 100644 --- a/drivers/gpu/drm/msm/msm_gpu.h +++ b/drivers/gpu/drm/msm/msm_gpu.h @@ -366,10 +366,18 @@ struct msm_file_private { */ int sysprof; - /** comm: Overridden task comm, see MSM_PARAM_COMM */ + /** + * comm: Overridden task comm, see MSM_PARAM_COMM + * + * Accessed under msm_gpu::lock + */ char *comm; - /** cmdline: Overridden task cmdline, see MSM_PARAM_CMDLINE */ + /** + * cmdline: Overridden task cmdline, see MSM_PARAM_CMDLINE + * + * Accessed under msm_gpu::lock + */ char *cmdline; /** -- cgit v1.2.3