From 29d08b3efddca628b0360411ab2b85f7b1723f48 Mon Sep 17 00:00:00 2001 From: Dave Airlie Date: Mon, 27 Sep 2010 16:17:17 +1000 Subject: drm/gem: handlecount isn't really a kref so don't make it one. There were lots of places being inconsistent since handle count looked like a kref but it really wasn't. Fix this my just making handle count an atomic on the object, and have it increase the normal object kref. Now i915/radeon/nouveau drivers can drop the normal reference on userspace object creation, and have the handle hold it. This patch fixes a memory leak or corruption on unload, because the driver had no way of knowing if a handle had been actually added for this object, and the fbcon object needed to know this to clean itself up properly. Reviewed-by: Chris Wilson Signed-off-by: Dave Airlie --- drivers/gpu/drm/i915/i915_gem.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) (limited to 'drivers/gpu/drm/i915/i915_gem.c') diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index cf4ffbee1c00..4cdf74264ee8 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -136,14 +136,12 @@ i915_gem_create_ioctl(struct drm_device *dev, void *data, return -ENOMEM; ret = drm_gem_handle_create(file_priv, obj, &handle); + /* drop reference from allocate - handle holds it now */ + drm_gem_object_unreference_unlocked(obj); if (ret) { - drm_gem_object_unreference_unlocked(obj); return ret; } - /* Sink the floating reference from kref_init(handlecount) */ - drm_gem_object_handle_unreference_unlocked(obj); - args->handle = handle; return 0; } -- cgit v1.2.3 From 929f49bf225b1b6cd04d0a7b9c0f7377d9131220 Mon Sep 17 00:00:00 2001 From: Julia Lawall Date: Sat, 2 Oct 2010 15:59:17 +0200 Subject: drivers/gpu/drm/i915/i915_gem.c: Add missing error handling code Extend the error handling code with operations found in other nearby error handling code A simplified version of the sematic match that finds this problem is as follows: (http://coccinelle.lip6.fr/) // @r exists@ @r@ statement S1,S2,S3; constant C1,C2,C3; @@ *if (...) {... S1 return -C1;} ... *if (...) {... when != S1 return -C2;} ... *if (...) {... S1 return -C3;} // Signed-off-by: Julia Lawall Signed-off-by: Chris Wilson Cc: stable@kernel.org --- drivers/gpu/drm/i915/i915_gem.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'drivers/gpu/drm/i915/i915_gem.c') diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index bced9b25c71e..cfe597865f5d 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -3258,6 +3258,8 @@ i915_gem_object_pin_and_relocate(struct drm_gem_object *obj, (int) reloc->offset, reloc->read_domains, reloc->write_domain); + drm_gem_object_unreference(target_obj); + i915_gem_object_unpin(obj); return -EINVAL; } if (reloc->write_domain & I915_GEM_DOMAIN_CPU || -- cgit v1.2.3 From ce9d419dbecc292cc3e06e8b1d6d123d3fa813a4 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Sun, 26 Sep 2010 20:50:05 +0100 Subject: drm/i915: Sanity check pread/pwrite Move the access control up from the fast paths, which are no longer universally taken first, up into the caller. This then duplicates some sanity checking along the slow paths, but is much simpler. Tracked as CVE-2010-2962. Reported-by: Kees Cook Signed-off-by: Chris Wilson Cc: stable@kernel.org --- drivers/gpu/drm/i915/i915_gem.c | 28 ++++++++++++++++++++-------- 1 file changed, 20 insertions(+), 8 deletions(-) (limited to 'drivers/gpu/drm/i915/i915_gem.c') diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index cfe597865f5d..7749e78a7300 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -477,8 +477,15 @@ i915_gem_pread_ioctl(struct drm_device *dev, void *data, */ if (args->offset > obj->size || args->size > obj->size || args->offset + args->size > obj->size) { - drm_gem_object_unreference_unlocked(obj); - return -EINVAL; + ret = -EINVAL; + goto err; + } + + if (!access_ok(VERIFY_WRITE, + (char __user *)(uintptr_t)args->data_ptr, + args->size)) { + ret = -EFAULT; + goto err; } if (i915_gem_object_needs_bit17_swizzle(obj)) { @@ -490,8 +497,8 @@ i915_gem_pread_ioctl(struct drm_device *dev, void *data, file_priv); } +err: drm_gem_object_unreference_unlocked(obj); - return ret; } @@ -580,8 +587,6 @@ i915_gem_gtt_pwrite_fast(struct drm_device *dev, struct drm_gem_object *obj, user_data = (char __user *) (uintptr_t) args->data_ptr; remain = args->size; - if (!access_ok(VERIFY_READ, user_data, remain)) - return -EFAULT; mutex_lock(&dev->struct_mutex); @@ -940,8 +945,15 @@ i915_gem_pwrite_ioctl(struct drm_device *dev, void *data, */ if (args->offset > obj->size || args->size > obj->size || args->offset + args->size > obj->size) { - drm_gem_object_unreference_unlocked(obj); - return -EINVAL; + ret = -EINVAL; + goto err; + } + + if (!access_ok(VERIFY_READ, + (char __user *)(uintptr_t)args->data_ptr, + args->size)) { + ret = -EFAULT; + goto err; } /* We can only do the GTT pwrite on untiled buffers, as otherwise @@ -975,8 +987,8 @@ i915_gem_pwrite_ioctl(struct drm_device *dev, void *data, DRM_INFO("pwrite failed %d\n", ret); #endif +err: drm_gem_object_unreference_unlocked(obj); - return ret; } -- cgit v1.2.3 From 7dcd2499deab8f10011713c40bc2f309c9b65077 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Sun, 26 Sep 2010 20:21:44 +0100 Subject: drm/i915: Rephrase pwrite bounds checking to avoid any potential overflow ... and do the same for pread. Signed-off-by: Chris Wilson Cc: stable@kernel.org --- drivers/gpu/drm/i915/i915_gem.c | 16 ++++------------ 1 file changed, 4 insertions(+), 12 deletions(-) (limited to 'drivers/gpu/drm/i915/i915_gem.c') diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 7749e78a7300..aa959c4a1836 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -471,12 +471,8 @@ i915_gem_pread_ioctl(struct drm_device *dev, void *data, return -ENOENT; obj_priv = to_intel_bo(obj); - /* Bounds check source. - * - * XXX: This could use review for overflow issues... - */ - if (args->offset > obj->size || args->size > obj->size || - args->offset + args->size > obj->size) { + /* Bounds check source. */ + if (args->offset > obj->size || args->size > obj->size - args->offset) { ret = -EINVAL; goto err; } @@ -939,12 +935,8 @@ i915_gem_pwrite_ioctl(struct drm_device *dev, void *data, return -ENOENT; obj_priv = to_intel_bo(obj); - /* Bounds check destination. - * - * XXX: This could use review for overflow issues... - */ - if (args->offset > obj->size || args->size > obj->size || - args->offset + args->size > obj->size) { + /* Bounds check destination. */ + if (args->offset > obj->size || args->size > obj->size - args->offset) { ret = -EINVAL; goto err; } -- cgit v1.2.3