| Message ID | 20201126082817.1242995-1-iskren.chernev@gmail.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | drm/msm: Fix use-after-free in msm_gem with carveout | expand |
Hi Iskren,
Thank you for the patch! Yet something to improve:
[auto build test ERROR on next-20201125]
[also build test ERROR on 6147c83fd749d19a0d3ccc2f64d12138ab010b47]
[cannot apply to drm-intel/for-linux-next drm-tip/drm-tip linus/master robclark/msm-next v5.10-rc5 v5.10-rc4 v5.10-rc3 v5.10-rc5]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]
url: https://github.com/0day-ci/linux/commits/Iskren-Chernev/drm-msm-Fix-use-after-free-in-msm_gem-with-carveout/20201126-163426
base: 9d3e48f20e1159a7bb2ff5de96594b6375157fe0
config: arm-defconfig (attached as .config)
compiler: arm-linux-gnueabi-gcc (GCC) 9.3.0
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/0day-ci/linux/commit/b08a39143f118f378b9fbb9ccfa03999dc419b1c
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Iskren-Chernev/drm-msm-Fix-use-after-free-in-msm_gem-with-carveout/20201126-163426
git checkout b08a39143f118f378b9fbb9ccfa03999dc419b1c
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=arm
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
All errors (new ones prefixed by >>):
In file included from arch/arm/include/asm/bug.h:60,
from include/linux/bug.h:5,
from include/linux/thread_info.h:12,
from include/asm-generic/current.h:5,
from ./arch/arm/include/generated/asm/current.h:1,
from include/linux/sched.h:12,
from include/linux/ratelimit.h:6,
from include/linux/dev_printk.h:16,
from include/linux/device.h:15,
from include/linux/dma-mapping.h:7,
from include/linux/dma-map-ops.h:9,
from drivers/gpu/drm/msm/msm_gem.c:7:
drivers/gpu/drm/msm/msm_gem.c: In function 'put_iova_vmas':
>> drivers/gpu/drm/msm/msm_gem.c:380:35: error: 'struct msm_gem_object' has no member named 'lock'
380 | WARN_ON(!mutex_is_locked(&msm_obj->lock));
| ^~
include/asm-generic/bug.h:119:25: note: in definition of macro 'WARN_ON'
119 | int __ret_warn_on = !!(condition); \
| ^~~~~~~~~
drivers/gpu/drm/msm/msm_gem.c: In function 'msm_gem_free_object':
>> drivers/gpu/drm/msm/msm_gem.c:983:2: error: implicit declaration of function 'put_iova_vma'; did you mean 'put_iova_vmas'? [-Werror=implicit-function-declaration]
983 | put_iova_vma(obj);
| ^~~~~~~~~~~~
| put_iova_vmas
cc1: some warnings being treated as errors
vim +380 drivers/gpu/drm/msm/msm_gem.c
372
373 /* Called with msm_obj locked */
374 static void
375 put_iova_vmas(struct drm_gem_object *obj)
376 {
377 struct msm_gem_object *msm_obj = to_msm_bo(obj);
378 struct msm_gem_vma *vma, *tmp;
379
> 380 WARN_ON(!mutex_is_locked(&msm_obj->lock));
381
382 list_for_each_entry_safe(vma, tmp, &msm_obj->vmas, list) {
383 del_vma(vma);
384 }
385 }
386
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c index 15715a156620f..b83247202ea5d 100644 --- a/drivers/gpu/drm/msm/msm_gem.c +++ b/drivers/gpu/drm/msm/msm_gem.c @@ -355,18 +355,31 @@ static void del_vma(struct msm_gem_vma *vma) /* Called with msm_obj locked */ static void -put_iova(struct drm_gem_object *obj) +put_iova_spaces(struct drm_gem_object *obj) { struct msm_gem_object *msm_obj = to_msm_bo(obj); - struct msm_gem_vma *vma, *tmp; + struct msm_gem_vma *vma; WARN_ON(!msm_gem_is_locked(obj)); - list_for_each_entry_safe(vma, tmp, &msm_obj->vmas, list) { + list_for_each_entry(vma, &msm_obj->vmas, list) { if (vma->aspace) { msm_gem_purge_vma(vma->aspace, vma); msm_gem_close_vma(vma->aspace, vma); } + } +} + +/* Called with msm_obj locked */ +static void +put_iova_vmas(struct drm_gem_object *obj) +{ + struct msm_gem_object *msm_obj = to_msm_bo(obj); + struct msm_gem_vma *vma, *tmp; + + WARN_ON(!mutex_is_locked(&msm_obj->lock)); + + list_for_each_entry_safe(vma, tmp, &msm_obj->vmas, list) { del_vma(vma); } } @@ -688,12 +701,14 @@ void msm_gem_purge(struct drm_gem_object *obj) WARN_ON(!is_purgeable(msm_obj)); WARN_ON(obj->import_attach); - put_iova(obj); + put_iova_spaces(obj); msm_gem_vunmap(obj); put_pages(obj); + put_iova_vmas(obj); + msm_obj->madv = __MSM_MADV_PURGED; drm_vma_node_unmap(&obj->vma_node, dev->anon_inode->i_mapping); @@ -942,7 +957,7 @@ void msm_gem_free_object(struct drm_gem_object *obj) msm_gem_lock(obj); - put_iova(obj); + put_iova_spaces(obj); if (obj->import_attach) { WARN_ON(msm_obj->vaddr); @@ -965,6 +980,8 @@ void msm_gem_free_object(struct drm_gem_object *obj) msm_gem_unlock(obj); } + put_iova_vma(obj); + drm_gem_object_release(obj); kfree(msm_obj);
When using gem with vram carveout the page allocation is managed via drm_mm. The necessary drm_mm_node is allocated in add_vma, but it freed before the drm_mm_node has been deallocated leading to use-after-free on every single vram allocation. Currently put_iova is called before free_object. put_iova -> del_vma -> kfree(vma) // vma holds drm_mm_node free_object -> put_pages -> put_pages_vram -> drm_mm_remove_node It looks like del_vma does nothing else other than freeing the vma object and removing it from it's list, so delaying the deletion should be harmless. This patch splits put_iova in put_iova_spaces and put_iova_vmas, so the vma can be freed after the mm_node has been deallocated with the mm. Signed-off-by: Iskren Chernev <iskren.chernev@gmail.com> --- drivers/gpu/drm/msm/msm_gem.c | 27 ++++++++++++++++++++++----- 1 file changed, 22 insertions(+), 5 deletions(-) base-commit: 6147c83fd749d19a0d3ccc2f64d12138ab010b47