diff options
| author | Jia Yang <jiayang5@huawei.com> | 2020-07-14 10:32:36 +0200 |
|---|---|---|
| committer | Thomas Zimmermann <tzimmermann@suse.de> | 2020-09-14 14:28:47 +0200 |
| commit | da62cb7230f0871c30dc9789071f63229158d261 (patch) | |
| tree | e35b143a6fa42068bfc2bb7cc613e89de35cb9d1 /drivers/gpu/drm | |
| parent | drm/vboxvideo: Use drm_gem_vram_vmap() interfaces (diff) | |
| download | linux-da62cb7230f0871c30dc9789071f63229158d261.tar.xz linux-da62cb7230f0871c30dc9789071f63229158d261.zip | |
drm: fix double free for gbo in drm_gem_vram_init and drm_gem_vram_create
I got a use-after-free report when doing some fuzz test:
If ttm_bo_init() fails, the "gbo" and "gbo->bo.base" will be
freed by ttm_buffer_object_destroy() in ttm_bo_init(). But
then drm_gem_vram_create() and drm_gem_vram_init() will free
"gbo" and "gbo->bo.base" again.
BUG: KMSAN: use-after-free in drm_vma_offset_remove+0xb3/0x150
CPU: 0 PID: 24282 Comm: syz-executor.1 Tainted: G B W 5.7.0-rc4-msan #2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
Call Trace:
__dump_stack
dump_stack+0x1c9/0x220
kmsan_report+0xf7/0x1e0
__msan_warning+0x58/0xa0
drm_vma_offset_remove+0xb3/0x150
drm_gem_free_mmap_offset
drm_gem_object_release+0x159/0x180
drm_gem_vram_init
drm_gem_vram_create+0x7c5/0x990
drm_gem_vram_fill_create_dumb
drm_gem_vram_driver_dumb_create+0x238/0x590
drm_mode_create_dumb
drm_mode_create_dumb_ioctl+0x41d/0x450
drm_ioctl_kernel+0x5a4/0x710
drm_ioctl+0xc6f/0x1240
vfs_ioctl
ksys_ioctl
__do_sys_ioctl
__se_sys_ioctl+0x2e9/0x410
__x64_sys_ioctl+0x4a/0x70
do_syscall_64+0xb8/0x160
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x4689b9
Code: fd e0 fa ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 cb e0 fa ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f368fa4dc98 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 000000000076bf00 RCX: 00000000004689b9
RDX: 0000000020000240 RSI: 00000000c02064b2 RDI: 0000000000000003
RBP: 0000000000000004 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00000000004d17e0 R14: 00007f368fa4e6d4 R15: 000000000076bf0c
Uninit was created at:
kmsan_save_stack_with_flags
kmsan_internal_poison_shadow+0x66/0xd0
kmsan_slab_free+0x6e/0xb0
slab_free_freelist_hook
slab_free
kfree+0x571/0x30a0
drm_gem_vram_destroy
ttm_buffer_object_destroy+0xc8/0x130
ttm_bo_release
kref_put
ttm_bo_put+0x117d/0x23e0
ttm_bo_init_reserved+0x11c0/0x11d0
ttm_bo_init+0x289/0x3f0
drm_gem_vram_init
drm_gem_vram_create+0x775/0x990
drm_gem_vram_fill_create_dumb
drm_gem_vram_driver_dumb_create+0x238/0x590
drm_mode_create_dumb
drm_mode_create_dumb_ioctl+0x41d/0x450
drm_ioctl_kernel+0x5a4/0x710
drm_ioctl+0xc6f/0x1240
vfs_ioctl
ksys_ioctl
__do_sys_ioctl
__se_sys_ioctl+0x2e9/0x410
__x64_sys_ioctl+0x4a/0x70
do_syscall_64+0xb8/0x160
entry_SYSCALL_64_after_hwframe+0x44/0xa9
If ttm_bo_init() fails, the "gbo" will be freed by
ttm_buffer_object_destroy() in ttm_bo_init(). But then
drm_gem_vram_create() and drm_gem_vram_init() will free
"gbo" again.
Reported-by: Hulk Robot <hulkci@huawei.com>
Reported-by: butt3rflyh4ck <butterflyhuangxx@gmail.com>
Signed-off-by: Jia Yang <jiayang5@huawei.com>
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20200714083238.28479-2-tzimmermann@suse.de
Diffstat (limited to 'drivers/gpu/drm')
| -rw-r--r-- | drivers/gpu/drm/drm_gem_vram_helper.c | 28 |
1 files changed, 16 insertions, 12 deletions
diff --git a/drivers/gpu/drm/drm_gem_vram_helper.c b/drivers/gpu/drm/drm_gem_vram_helper.c index 11e396c5048a..4291f0b71021 100644 --- a/drivers/gpu/drm/drm_gem_vram_helper.c +++ b/drivers/gpu/drm/drm_gem_vram_helper.c @@ -167,6 +167,10 @@ static void drm_gem_vram_placement(struct drm_gem_vram_object *gbo, } } +/* + * Note that on error, drm_gem_vram_init will free the buffer object. + */ + static int drm_gem_vram_init(struct drm_device *dev, struct drm_gem_vram_object *gbo, size_t size, unsigned long pg_align) @@ -176,15 +180,19 @@ static int drm_gem_vram_init(struct drm_device *dev, int ret; size_t acc_size; - if (WARN_ONCE(!vmm, "VRAM MM not initialized")) + if (WARN_ONCE(!vmm, "VRAM MM not initialized")) { + kfree(gbo); return -EINVAL; + } bdev = &vmm->bdev; gbo->bo.base.funcs = &drm_gem_vram_object_funcs; ret = drm_gem_object_init(dev, &gbo->bo.base, size); - if (ret) + if (ret) { + kfree(gbo); return ret; + } acc_size = ttm_bo_dma_acc_size(bdev, size, sizeof(*gbo)); @@ -196,13 +204,13 @@ static int drm_gem_vram_init(struct drm_device *dev, &gbo->placement, pg_align, false, acc_size, NULL, NULL, ttm_buffer_object_destroy); if (ret) - goto err_drm_gem_object_release; + /* + * A failing ttm_bo_init will call ttm_buffer_object_destroy + * to release gbo->bo.base and kfree gbo. + */ + return ret; return 0; - -err_drm_gem_object_release: - drm_gem_object_release(&gbo->bo.base); - return ret; } /** @@ -236,13 +244,9 @@ struct drm_gem_vram_object *drm_gem_vram_create(struct drm_device *dev, ret = drm_gem_vram_init(dev, gbo, size, pg_align); if (ret < 0) - goto err_kfree; + return ERR_PTR(ret); return gbo; - -err_kfree: - kfree(gbo); - return ERR_PTR(ret); } EXPORT_SYMBOL(drm_gem_vram_create); |