From 429aec2bc0ae1e20ce96066d57e9f91f79b660df Mon Sep 17 00:00:00 2001 From: Srinivasan Shanmugam Date: Mon, 23 Mar 2026 14:28:57 +0530 Subject: [PATCH] drm/amdkfd: Fix NULL pointer check order in kfd_ioctl_create_process MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit In kfd_ioctl_create_process(), the pointer 'p' is used before checking if it is NULL. The code accesses p->context_id before validating 'p'. This can lead to a possible NULL pointer dereference. Move the NULL check before using 'p' so that the pointer is validated before access. Fixes the below: drivers/gpu/drm/amd/amdgpu/../amdkfd/kfd_chardev.c:3177 kfd_ioctl_create_process() warn: variable dereferenced before check 'p' (see line 3174) Fixes: cc6b66d661fd ("amdkfd: introduce new ioctl AMDKFD_IOC_CREATE_PROCESS") Cc: Zhu Lingshan Cc: Felix Kuehling Cc: Christian König Cc: Alex Deucher Cc: Dan Carpenter Signed-off-by: Srinivasan Shanmugam Reviewed-by: Christian König Signed-off-by: Alex Deucher (cherry picked from commit 19d4149b22f57094bfc4b86b742381b3ca394ead) --- drivers/gpu/drm/amd/amdkfd/kfd_chardev.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c index 09dabb3b3297..462a32abf720 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c +++ b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c @@ -3170,11 +3170,11 @@ static int kfd_ioctl_create_process(struct file *filep, struct kfd_process *p, v struct kfd_process *process; int ret; - /* Each FD owns only one kfd_process */ - if (p->context_id != KFD_CONTEXT_ID_PRIMARY) + if (!filep->private_data || !p) return -EINVAL; - if (!filep->private_data || !p) + /* Each FD owns only one kfd_process */ + if (p->context_id != KFD_CONTEXT_ID_PRIMARY) return -EINVAL; mutex_lock(&kfd_processes_mutex);