From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dmitry Osipenko Subject: [PATCH 3/3] drm/tegra: Check size of a submitted command buffer Date: Fri, 12 May 2017 22:02:12 +0300 Message-ID: <20170512190212.17798-1-digetx@gmail.com> Return-path: Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Thierry Reding Cc: linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, DRI Development , Erik Faye-Lund List-Id: linux-tegra@vger.kernel.org If command buffer claims a number of words that is higher than its BO can fit and a relocation lays past the BO, a kernel OOPS will be fired on that relocation address patching. This was triggered by an opentegra Xorg driver that erroneously pushed too many commands to the pushbuf. [ 46.829393] Unable to handle kernel paging request at virtual address f09b2000 ... [] (host1x_job_pin) from [] (tegra_drm_submit+0x474/0x510) [] (tegra_drm_submit) from [] (tegra_submit+0x50/0x6c) [] (tegra_submit) from [] (drm_ioctl+0x1e4/0x3ec) [] (drm_ioctl) from [] (do_vfs_ioctl+0x9c/0x8e4) [] (do_vfs_ioctl) from [] (SyS_ioctl+0x34/0x5c) [] (SyS_ioctl) from [] (ret_fast_syscall+0x0/0x3c) Signed-off-by: Dmitry Osipenko --- drivers/gpu/drm/tegra/drm.c | 18 ++++++++++++++---- 1 file changed, 14 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/tegra/drm.c b/drivers/gpu/drm/tegra/drm.c index 732c8d98044f..e9c74a7780e7 100644 --- a/drivers/gpu/drm/tegra/drm.c +++ b/drivers/gpu/drm/tegra/drm.c @@ -361,20 +361,30 @@ int tegra_drm_submit(struct tegra_drm_context *context, while (num_cmdbufs) { struct drm_tegra_cmdbuf cmdbuf; - struct host1x_bo *bo; + struct drm_gem_object *gem; + struct tegra_bo *bo; if (copy_from_user(&cmdbuf, cmdbufs, sizeof(cmdbuf))) { err = -EFAULT; goto fail; } - bo = host1x_bo_lookup(file, cmdbuf.handle); - if (!bo) { + gem = drm_gem_object_lookup(file, cmdbuf.handle); + if (!gem) { err = -ENOENT; goto fail; } - host1x_job_add_gather(job, bo, cmdbuf.words, cmdbuf.offset); + drm_gem_object_unreference_unlocked(gem); + + if (cmdbuf.words * 4 > gem->size) { + err = -EINVAL; + goto fail; + } + + bo = to_tegra_bo(gem); + host1x_job_add_gather(job, &bo->base, + cmdbuf.words, cmdbuf.offset); num_cmdbufs--; cmdbufs++; } -- 2.12.2