Messages in this thread Patch in this message | | | From | Jiri Slaby <> | Subject | [PATCH 3.12 058/119] drm/msm: fix use of copy_from_user() while holding spinlock | Date | Thu, 29 Sep 2016 12:24:54 +0200 |
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From: Rob Clark <robdclark@gmail.com>
3.12-stable review patch. If anyone has any objections, please let me know.
===============
commit 89f82cbb0d5c0ab768c8d02914188aa2211cd2e3 upstream.
Use instead __copy_from_user_inatomic() and fallback to slow-path where we drop and re-aquire the lock in case of fault.
Reported-by: Vaishali Thakkar <vaishali.thakkar@oracle.com> Signed-off-by: Rob Clark <robdclark@gmail.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz> --- drivers/gpu/drm/msm/msm_gem_submit.c | 27 ++++++++++++++++++++++----- 1 file changed, 22 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/msm/msm_gem_submit.c b/drivers/gpu/drm/msm/msm_gem_submit.c index 5281d4bc37f7..d0fc019be5df 100644 --- a/drivers/gpu/drm/msm/msm_gem_submit.c +++ b/drivers/gpu/drm/msm/msm_gem_submit.c @@ -56,6 +56,14 @@ static struct msm_gem_submit *submit_create(struct drm_device *dev, return submit; } +static inline unsigned long __must_check +copy_from_user_inatomic(void *to, const void __user *from, unsigned long n) +{ + if (access_ok(VERIFY_READ, from, n)) + return __copy_from_user_inatomic(to, from, n); + return -EFAULT; +} + static int submit_lookup_objects(struct msm_gem_submit *submit, struct drm_msm_gem_submit *args, struct drm_file *file) { @@ -63,6 +71,7 @@ static int submit_lookup_objects(struct msm_gem_submit *submit, int ret = 0; spin_lock(&file->table_lock); + pagefault_disable(); for (i = 0; i < args->nr_bos; i++) { struct drm_msm_gem_submit_bo submit_bo; @@ -71,10 +80,15 @@ static int submit_lookup_objects(struct msm_gem_submit *submit, void __user *userptr = to_user_ptr(args->bos + (i * sizeof(submit_bo))); - ret = copy_from_user(&submit_bo, userptr, sizeof(submit_bo)); - if (ret) { - ret = -EFAULT; - goto out_unlock; + ret = copy_from_user_inatomic(&submit_bo, userptr, sizeof(submit_bo)); + if (unlikely(ret)) { + pagefault_enable(); + spin_unlock(&file->table_lock); + ret = copy_from_user(&submit_bo, userptr, sizeof(submit_bo)); + if (ret) + goto out; + spin_lock(&file->table_lock); + pagefault_disable(); } if (submit_bo.flags & BO_INVALID_FLAGS) { @@ -114,9 +128,12 @@ static int submit_lookup_objects(struct msm_gem_submit *submit, } out_unlock: - submit->nr_bos = i; + pagefault_enable(); spin_unlock(&file->table_lock); +out: + submit->nr_bos = i; + return ret; } -- 2.10.0
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