From 368f622c0d76a22662af33759be8c4408819295d Mon Sep 17 00:00:00 2001 From: Dmitry Osipenko Date: Thu, 15 Jun 2017 02:18:26 +0300 Subject: drm/tegra: Check for malformed offsets and sizes in the 'submit' IOCTL If commands buffer claims a number of words that is higher than its BO can fit, a kernel OOPS will be fired on the out-of-bounds BO access. This was triggered by an opentegra Xorg driver that erroneously pushed too many commands to the pushbuf. The CDMA commands buffer address is 4 bytes aligned, so check its alignment. The maximum number of the CDMA gather fetches is 16383, add a check for it. Add a sanity check for the relocations in a same way. [ 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 Reviewed-by: Erik Faye-Lund Reviewed-by: Mikko Perttunen Signed-off-by: Thierry Reding --- drivers/gpu/drm/tegra/drm.c | 49 +++++++++++++++++++++++++++++++++++++++++++++ drivers/gpu/drm/tegra/gem.c | 5 ----- drivers/gpu/drm/tegra/gem.h | 5 +++++ 3 files changed, 54 insertions(+), 5 deletions(-) (limited to 'drivers') diff --git a/drivers/gpu/drm/tegra/drm.c b/drivers/gpu/drm/tegra/drm.c index 9a1e34e48f64..51e20e015053 100644 --- a/drivers/gpu/drm/tegra/drm.c +++ b/drivers/gpu/drm/tegra/drm.c @@ -26,6 +26,7 @@ #define DRIVER_PATCHLEVEL 0 #define CARVEOUT_SZ SZ_64M +#define CDMA_GATHER_FETCHES_MAX_NB 16383 struct tegra_drm_file { struct idr contexts; @@ -383,18 +384,42 @@ int tegra_drm_submit(struct tegra_drm_context *context, while (num_cmdbufs) { struct drm_tegra_cmdbuf cmdbuf; struct host1x_bo *bo; + struct tegra_bo *obj; + u64 offset; if (copy_from_user(&cmdbuf, cmdbufs, sizeof(cmdbuf))) { err = -EFAULT; goto fail; } + /* + * The maximum number of CDMA gather fetches is 16383, a higher + * value means the words count is malformed. + */ + if (cmdbuf.words > CDMA_GATHER_FETCHES_MAX_NB) { + err = -EINVAL; + goto fail; + } + bo = host1x_bo_lookup(file, cmdbuf.handle); if (!bo) { err = -ENOENT; goto fail; } + offset = (u64)cmdbuf.offset + (u64)cmdbuf.words * sizeof(u32); + obj = host1x_to_tegra_bo(bo); + + /* + * Gather buffer base address must be 4-bytes aligned, + * unaligned offset is malformed and cause commands stream + * corruption on the buffer address relocation. + */ + if (offset & 3 || offset >= obj->gem.size) { + err = -EINVAL; + goto fail; + } + host1x_job_add_gather(job, bo, cmdbuf.words, cmdbuf.offset); num_cmdbufs--; cmdbufs++; @@ -402,11 +427,35 @@ int tegra_drm_submit(struct tegra_drm_context *context, /* copy and resolve relocations from submit */ while (num_relocs--) { + struct host1x_reloc *reloc; + struct tegra_bo *obj; + err = host1x_reloc_copy_from_user(&job->relocarray[num_relocs], &relocs[num_relocs], drm, file); if (err < 0) goto fail; + + reloc = &job->relocarray[num_relocs]; + obj = host1x_to_tegra_bo(reloc->cmdbuf.bo); + + /* + * The unaligned cmdbuf offset will cause an unaligned write + * during of the relocations patching, corrupting the commands + * stream. + */ + if (reloc->cmdbuf.offset & 3 || + reloc->cmdbuf.offset >= obj->gem.size) { + err = -EINVAL; + goto fail; + } + + obj = host1x_to_tegra_bo(reloc->target.bo); + + if (reloc->target.offset >= obj->gem.size) { + err = -EINVAL; + goto fail; + } } if (copy_from_user(job->waitchk, waitchks, diff --git a/drivers/gpu/drm/tegra/gem.c b/drivers/gpu/drm/tegra/gem.c index 424569b53e57..7a39a355678a 100644 --- a/drivers/gpu/drm/tegra/gem.c +++ b/drivers/gpu/drm/tegra/gem.c @@ -20,11 +20,6 @@ #include "drm.h" #include "gem.h" -static inline struct tegra_bo *host1x_to_tegra_bo(struct host1x_bo *bo) -{ - return container_of(bo, struct tegra_bo, base); -} - static void tegra_bo_put(struct host1x_bo *bo) { struct tegra_bo *obj = host1x_to_tegra_bo(bo); diff --git a/drivers/gpu/drm/tegra/gem.h b/drivers/gpu/drm/tegra/gem.h index 6c5f12ac0087..8b32a6fd586d 100644 --- a/drivers/gpu/drm/tegra/gem.h +++ b/drivers/gpu/drm/tegra/gem.h @@ -52,6 +52,11 @@ static inline struct tegra_bo *to_tegra_bo(struct drm_gem_object *gem) return container_of(gem, struct tegra_bo, gem); } +static inline struct tegra_bo *host1x_to_tegra_bo(struct host1x_bo *bo) +{ + return container_of(bo, struct tegra_bo, base); +} + struct tegra_bo *tegra_bo_create(struct drm_device *drm, size_t size, unsigned long flags); struct tegra_bo *tegra_bo_create_with_handle(struct drm_file *file, -- cgit v1.2.3