From 3e04bc310d80b46eaf481f1fefcbcb37a187412d Mon Sep 17 00:00:00 2001 From: Sunday Clement Date: Mon, 2 Feb 2026 12:41:39 -0500 Subject: drm/amdkfd: Fix out-of-bounds write in kfd_event_page_set() [ Upstream commit 8a70a26c9f34baea6c3199a9862ddaff4554a96d ] The kfd_event_page_set() function writes KFD_SIGNAL_EVENT_LIMIT * 8 bytes via memset without checking the buffer size parameter. This allows unprivileged userspace to trigger an out-of bounds kernel memory write by passing a small buffer, leading to potential privilege escalation. Signed-off-by: Sunday Clement Reviewed-by: Alexander Deucher Signed-off-by: Alex Deucher Cc: stable@vger.kernel.org Signed-off-by: Sasha Levin --- drivers/gpu/drm/amd/amdkfd/kfd_events.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_events.c b/drivers/gpu/drm/amd/amdkfd/kfd_events.c index 2c19b3775179..00266e20e7ab 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_events.c +++ b/drivers/gpu/drm/amd/amdkfd/kfd_events.c @@ -303,6 +303,12 @@ int kfd_event_page_set(struct kfd_process *p, void *kernel_address, if (p->signal_page) return -EBUSY; + if (size < KFD_SIGNAL_EVENT_LIMIT * 8) { + pr_err("Event page size %llu is too small, need at least %lu bytes\n", + size, (unsigned long)(KFD_SIGNAL_EVENT_LIMIT * 8)); + return -EINVAL; + } + page = kzalloc(sizeof(*page), GFP_KERNEL); if (!page) return -ENOMEM; -- cgit v1.2.3