The user program can control the 'drm_buf_desc::flags' via ioctl system call and enter the function drm_legacy_addbufs_agp(). If the driver doesn't initialize the agp resources, the driver will cause a null pointer dereference.
The following log reveals it: general protection fault, probably for non-canonical address 0xdffffc000000000f: 0000 [#1] PREEMPT SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000078-0x000000000000007f] Call Trace: <TASK> drm_ioctl_kernel+0x342/0x450 drivers/gpu/drm/drm_ioctl.c:785 drm_ioctl+0x592/0x940 drivers/gpu/drm/drm_ioctl.c:885 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl+0xaa/0xf0 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x43/0x90 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae
Fix this bug by adding a check.
Signed-off-by: Zheyu Ma zheyuma97@gmail.com --- drivers/gpu/drm/drm_bufs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/drm_bufs.c b/drivers/gpu/drm/drm_bufs.c index fcca21e8efac..4fe2363b1e34 100644 --- a/drivers/gpu/drm/drm_bufs.c +++ b/drivers/gpu/drm/drm_bufs.c @@ -734,7 +734,7 @@ int drm_legacy_addbufs_agp(struct drm_device *dev, int i, valid; struct drm_buf **temp_buflist;
- if (!dma) + if (!dma || !dev->agp) return -EINVAL;
count = request->count;
On Fri, Mar 11, 2022 at 07:23:02AM +0000, Zheyu Ma wrote:
The user program can control the 'drm_buf_desc::flags' via ioctl system call and enter the function drm_legacy_addbufs_agp(). If the driver doesn't initialize the agp resources, the driver will cause a null pointer dereference.
The following log reveals it: general protection fault, probably for non-canonical address 0xdffffc000000000f: 0000 [#1] PREEMPT SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000078-0x000000000000007f] Call Trace: <TASK> drm_ioctl_kernel+0x342/0x450 drivers/gpu/drm/drm_ioctl.c:785 drm_ioctl+0x592/0x940 drivers/gpu/drm/drm_ioctl.c:885 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl+0xaa/0xf0 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x43/0x90 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae
Fix this bug by adding a check.
Signed-off-by: Zheyu Ma zheyuma97@gmail.com
You can only hit this if you enabled a DRIVER_LEGACY drm driver, which opens you up to tons of other CVEs and issues. What's your .config? -Daniel
drivers/gpu/drm/drm_bufs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/drm_bufs.c b/drivers/gpu/drm/drm_bufs.c index fcca21e8efac..4fe2363b1e34 100644 --- a/drivers/gpu/drm/drm_bufs.c +++ b/drivers/gpu/drm/drm_bufs.c @@ -734,7 +734,7 @@ int drm_legacy_addbufs_agp(struct drm_device *dev, int i, valid; struct drm_buf **temp_buflist;
- if (!dma)
if (!dma || !dev->agp) return -EINVAL;
count = request->count;
-- 2.25.1
On Thu, Mar 17, 2022 at 6:49 PM Daniel Vetter daniel@ffwll.ch wrote:
On Fri, Mar 11, 2022 at 07:23:02AM +0000, Zheyu Ma wrote:
The user program can control the 'drm_buf_desc::flags' via ioctl system call and enter the function drm_legacy_addbufs_agp(). If the driver doesn't initialize the agp resources, the driver will cause a null pointer dereference.
The following log reveals it: general protection fault, probably for non-canonical address 0xdffffc000000000f: 0000 [#1] PREEMPT SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000078-0x000000000000007f] Call Trace: <TASK> drm_ioctl_kernel+0x342/0x450 drivers/gpu/drm/drm_ioctl.c:785 drm_ioctl+0x592/0x940 drivers/gpu/drm/drm_ioctl.c:885 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl+0xaa/0xf0 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x43/0x90 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae
Fix this bug by adding a check.
Signed-off-by: Zheyu Ma zheyuma97@gmail.com
You can only hit this if you enabled a DRIVER_LEGACY drm driver, which opens you up to tons of other CVEs and issues. What's your .config?
Yes, I enable the DRM_LEGACY option in the config. I think you mean this is not a normal configuration file? Do you have a recommended configuration option for when I want to test the GPU driver?
Actually, I use the following configs related to GPU:
CONFIG_AGP=y CONFIG_AGP_AMD64=y CONFIG_AGP_INTEL=y CONFIG_AGP_SIS=y CONFIG_AGP_VIA=y CONFIG_INTEL_GTT=y CONFIG_VGA_ARB=y CONFIG_VGA_ARB_MAX_GPUS=16 CONFIG_DRM=y CONFIG_DRM_MIPI_DSI=y CONFIG_DRM_KMS_HELPER=y CONFIG_DRM_DEBUG_MODESET_LOCK=y CONFIG_DRM_FBDEV_EMULATION=y CONFIG_DRM_FBDEV_OVERALLOC=100 CONFIG_DRM_TTM=y CONFIG_DRM_VRAM_HELPER=y CONFIG_DRM_TTM_HELPER=y CONFIG_DRM_GEM_SHMEM_HELPER=y CONFIG_DRM_SCHED=y CONFIG_DRM_RADEON=y CONFIG_DRM_AMDGPU=y CONFIG_DRM_AMD_DC=y CONFIG_DRM_AMD_DC_DCN=y CONFIG_DRM_I915=y CONFIG_DRM_I915_FORCE_PROBE="" CONFIG_DRM_I915_CAPTURE_ERROR=y CONFIG_DRM_I915_COMPRESS_ERROR=y CONFIG_DRM_I915_USERPTR=y CONFIG_DRM_I915_REQUEST_TIMEOUT=20000 CONFIG_DRM_I915_FENCE_TIMEOUT=10000 CONFIG_DRM_I915_USERFAULT_AUTOSUSPEND=250 CONFIG_DRM_I915_HEARTBEAT_INTERVAL=2500 CONFIG_DRM_I915_PREEMPT_TIMEOUT=640 CONFIG_DRM_I915_MAX_REQUEST_BUSYWAIT=8000 CONFIG_DRM_I915_STOP_TIMEOUT=100 CONFIG_DRM_I915_TIMESLICE_DURATION=1 CONFIG_DRM_VMWGFX=y CONFIG_DRM_GMA500=y CONFIG_DRM_UDL=y CONFIG_DRM_AST=y CONFIG_DRM_MGAG200=y CONFIG_DRM_QXL=y CONFIG_DRM_VIRTIO_GPU=y CONFIG_DRM_PANEL=y CONFIG_DRM_BRIDGE=y CONFIG_DRM_PANEL_BRIDGE=y CONFIG_DRM_BOCHS=y CONFIG_DRM_CIRRUS_QEMU=y CONFIG_DRM_GM12U320=y CONFIG_DRM_VBOXVIDEO=y CONFIG_DRM_GUD=y CONFIG_DRM_HYPERV=y CONFIG_DRM_LEGACY=y CONFIG_DRM_TDFX=y CONFIG_DRM_R128=y CONFIG_DRM_MGA=y CONFIG_DRM_SIS=y CONFIG_DRM_VIA=y CONFIG_DRM_SAVAGE=y CONFIG_DRM_PANEL_ORIENTATION_QUIRKS=y
Thanks, Zheyu Ma
On Mon, Mar 21, 2022 at 09:02:47PM +0800, Zheyu Ma wrote:
On Thu, Mar 17, 2022 at 6:49 PM Daniel Vetter daniel@ffwll.ch wrote:
On Fri, Mar 11, 2022 at 07:23:02AM +0000, Zheyu Ma wrote:
The user program can control the 'drm_buf_desc::flags' via ioctl system call and enter the function drm_legacy_addbufs_agp(). If the driver doesn't initialize the agp resources, the driver will cause a null pointer dereference.
The following log reveals it: general protection fault, probably for non-canonical address 0xdffffc000000000f: 0000 [#1] PREEMPT SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000078-0x000000000000007f] Call Trace: <TASK> drm_ioctl_kernel+0x342/0x450 drivers/gpu/drm/drm_ioctl.c:785 drm_ioctl+0x592/0x940 drivers/gpu/drm/drm_ioctl.c:885 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl+0xaa/0xf0 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x43/0x90 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae
Fix this bug by adding a check.
Signed-off-by: Zheyu Ma zheyuma97@gmail.com
You can only hit this if you enabled a DRIVER_LEGACY drm driver, which opens you up to tons of other CVEs and issues. What's your .config?
Yes, I enable the DRM_LEGACY option in the config. I think you mean this is not a normal configuration file? Do you have a recommended configuration option for when I want to test the GPU driver?
Yeah DRM_LEGACY gives you all kinds of horrible and known-broken interfaces. Don't enable that :-)
You have a bunch of other drivers enable which require DRM_LEGACY, so those will disable too. Anything else I think would be an upstream bug and we'd need to adjust Kconfig (or fix the code).
Cheers, Daniel
Actually, I use the following configs related to GPU:
CONFIG_AGP=y CONFIG_AGP_AMD64=y CONFIG_AGP_INTEL=y CONFIG_AGP_SIS=y CONFIG_AGP_VIA=y CONFIG_INTEL_GTT=y CONFIG_VGA_ARB=y CONFIG_VGA_ARB_MAX_GPUS=16 CONFIG_DRM=y CONFIG_DRM_MIPI_DSI=y CONFIG_DRM_KMS_HELPER=y CONFIG_DRM_DEBUG_MODESET_LOCK=y CONFIG_DRM_FBDEV_EMULATION=y CONFIG_DRM_FBDEV_OVERALLOC=100 CONFIG_DRM_TTM=y CONFIG_DRM_VRAM_HELPER=y CONFIG_DRM_TTM_HELPER=y CONFIG_DRM_GEM_SHMEM_HELPER=y CONFIG_DRM_SCHED=y CONFIG_DRM_RADEON=y CONFIG_DRM_AMDGPU=y CONFIG_DRM_AMD_DC=y CONFIG_DRM_AMD_DC_DCN=y CONFIG_DRM_I915=y CONFIG_DRM_I915_FORCE_PROBE="" CONFIG_DRM_I915_CAPTURE_ERROR=y CONFIG_DRM_I915_COMPRESS_ERROR=y CONFIG_DRM_I915_USERPTR=y CONFIG_DRM_I915_REQUEST_TIMEOUT=20000 CONFIG_DRM_I915_FENCE_TIMEOUT=10000 CONFIG_DRM_I915_USERFAULT_AUTOSUSPEND=250 CONFIG_DRM_I915_HEARTBEAT_INTERVAL=2500 CONFIG_DRM_I915_PREEMPT_TIMEOUT=640 CONFIG_DRM_I915_MAX_REQUEST_BUSYWAIT=8000 CONFIG_DRM_I915_STOP_TIMEOUT=100 CONFIG_DRM_I915_TIMESLICE_DURATION=1 CONFIG_DRM_VMWGFX=y CONFIG_DRM_GMA500=y CONFIG_DRM_UDL=y CONFIG_DRM_AST=y CONFIG_DRM_MGAG200=y CONFIG_DRM_QXL=y CONFIG_DRM_VIRTIO_GPU=y CONFIG_DRM_PANEL=y CONFIG_DRM_BRIDGE=y CONFIG_DRM_PANEL_BRIDGE=y CONFIG_DRM_BOCHS=y CONFIG_DRM_CIRRUS_QEMU=y CONFIG_DRM_GM12U320=y CONFIG_DRM_VBOXVIDEO=y CONFIG_DRM_GUD=y CONFIG_DRM_HYPERV=y CONFIG_DRM_LEGACY=y CONFIG_DRM_TDFX=y CONFIG_DRM_R128=y CONFIG_DRM_MGA=y CONFIG_DRM_SIS=y CONFIG_DRM_VIA=y CONFIG_DRM_SAVAGE=y CONFIG_DRM_PANEL_ORIENTATION_QUIRKS=y
Thanks, Zheyu Ma
On Tue, Mar 22, 2022 at 10:27 PM Daniel Vetter daniel@ffwll.ch wrote:
On Mon, Mar 21, 2022 at 09:02:47PM +0800, Zheyu Ma wrote:
On Thu, Mar 17, 2022 at 6:49 PM Daniel Vetter daniel@ffwll.ch wrote:
On Fri, Mar 11, 2022 at 07:23:02AM +0000, Zheyu Ma wrote:
The user program can control the 'drm_buf_desc::flags' via ioctl system call and enter the function drm_legacy_addbufs_agp(). If the driver doesn't initialize the agp resources, the driver will cause a null pointer dereference.
The following log reveals it: general protection fault, probably for non-canonical address 0xdffffc000000000f: 0000 [#1] PREEMPT SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000078-0x000000000000007f] Call Trace: <TASK> drm_ioctl_kernel+0x342/0x450 drivers/gpu/drm/drm_ioctl.c:785 drm_ioctl+0x592/0x940 drivers/gpu/drm/drm_ioctl.c:885 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl+0xaa/0xf0 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x43/0x90 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae
Fix this bug by adding a check.
Signed-off-by: Zheyu Ma zheyuma97@gmail.com
You can only hit this if you enabled a DRIVER_LEGACY drm driver, which opens you up to tons of other CVEs and issues. What's your .config?
Yes, I enable the DRM_LEGACY option in the config. I think you mean this is not a normal configuration file? Do you have a recommended configuration option for when I want to test the GPU driver?
Yeah DRM_LEGACY gives you all kinds of horrible and known-broken interfaces. Don't enable that :-)
You have a bunch of other drivers enable which require DRM_LEGACY, so those will disable too. Anything else I think would be an upstream bug and we'd need to adjust Kconfig (or fix the code).
Thanks for your explanation! I will pay attention next time.
Regards, Zheyu Ma
dri-devel@lists.freedesktop.org
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Daniel Vetter -
Zheyu Ma