Commit 368f622c authored by Dmitry Osipenko's avatar Dmitry Osipenko Committed by Thierry Reding

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
...
[<c04a3ba4>] (host1x_job_pin) from [<c04dfcd0>] (tegra_drm_submit+0x474/0x510)
[<c04dfcd0>] (tegra_drm_submit) from [<c04deea0>] (tegra_submit+0x50/0x6c)
[<c04deea0>] (tegra_submit) from [<c04c07c0>] (drm_ioctl+0x1e4/0x3ec)
[<c04c07c0>] (drm_ioctl) from [<c02541a0>] (do_vfs_ioctl+0x9c/0x8e4)
[<c02541a0>] (do_vfs_ioctl) from [<c0254a1c>] (SyS_ioctl+0x34/0x5c)
[<c0254a1c>] (SyS_ioctl) from [<c0107640>] (ret_fast_syscall+0x0/0x3c)
Signed-off-by: Dmitry Osipenko's avatarDmitry Osipenko <digetx@gmail.com>
Reviewed-by: Erik Faye-Lund 's avatarErik Faye-Lund <kusmabite@gmail.com>
Reviewed-by: default avatarMikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: default avatarThierry Reding <treding@nvidia.com>
parent fa6d095e
......@@ -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,
......
......@@ -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);
......
......@@ -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,
......
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