The firewall verified gather buffers before copying them. This allowed a malicious application to rewrite the buffer content by timing the rewrite carefully.
This patch makes the buffer validation occur after copying the buffers.
Signed-off-by: Arto Merilainen amerilainen@nvidia.com Signed-off-by: Terje Bergstrom tbergstrom@nvidia.com --- drivers/gpu/host1x/job.c | 50 +++++++++++++++++++----------------------------- 1 file changed, 20 insertions(+), 30 deletions(-)
diff --git a/drivers/gpu/host1x/job.c b/drivers/gpu/host1x/job.c index 028d2d4..cc80766 100644 --- a/drivers/gpu/host1x/job.c +++ b/drivers/gpu/host1x/job.c @@ -228,17 +228,15 @@ static unsigned int do_relocs(struct host1x_job *job, struct host1x_bo *cmdbuf) void *cmdbuf_page_addr = NULL;
/* pin & patch the relocs for one gather */ - while (i < job->num_relocs) { + for (i = 0; i < job->num_relocs; i++) { struct host1x_reloc *reloc = &job->relocarray[i]; u32 reloc_addr = (job->reloc_addr_phys[i] + reloc->target_offset) >> reloc->shift; u32 *target;
/* skip all other gathers */ - if (!(reloc->cmdbuf && cmdbuf == reloc->cmdbuf)) { - i++; + if (cmdbuf != reloc->cmdbuf) continue; - }
if (last_page != reloc->cmdbuf_offset >> PAGE_SHIFT) { if (cmdbuf_page_addr) @@ -257,9 +255,6 @@ static unsigned int do_relocs(struct host1x_job *job, struct host1x_bo *cmdbuf)
target = cmdbuf_page_addr + (reloc->cmdbuf_offset & ~PAGE_MASK); *target = reloc_addr; - - /* mark this gather as handled */ - reloc->cmdbuf = 0; }
if (cmdbuf_page_addr) @@ -378,15 +373,13 @@ static int check_nonincr(struct host1x_firewall *fw)
static int validate(struct host1x_firewall *fw, struct host1x_job_gather *g) { - u32 *cmdbuf_base; + u32 *cmdbuf_base = (u32 *)fw->job->gather_copy_mapped + + (g->offset / sizeof(u32)); int err = 0;
if (!fw->job->is_addr_reg) return 0;
- cmdbuf_base = host1x_bo_mmap(g->bo); - if (!cmdbuf_base) - return -ENOMEM; fw->words = g->words; fw->cmdbuf_id = g->bo; fw->offset = 0; @@ -453,10 +446,17 @@ out:
static inline int copy_gathers(struct host1x_job *job, struct device *dev) { + struct host1x_firewall fw; size_t size = 0; size_t offset = 0; int i;
+ fw.job = job; + fw.dev = dev; + fw.reloc = job->relocarray; + fw.num_relocs = job->num_relocs; + fw.class = 0; + for (i = 0; i < job->num_gathers; i++) { struct host1x_job_gather *g = &job->gathers[i]; size += g->words * sizeof(u32); @@ -477,14 +477,19 @@ static inline int copy_gathers(struct host1x_job *job, struct device *dev) struct host1x_job_gather *g = &job->gathers[i]; void *gather;
+ /* Copy the gather */ gather = host1x_bo_mmap(g->bo); memcpy(job->gather_copy_mapped + offset, gather + g->offset, g->words * sizeof(u32)); host1x_bo_munmap(g->bo, gather);
+ /* Store the location in the buffer */ g->base = job->gather_copy; g->offset = offset; - g->bo = NULL; + + /* Validate the job */ + if (validate(&fw, g)) + return -EINVAL;
offset += g->words * sizeof(u32); } @@ -497,15 +502,8 @@ int host1x_job_pin(struct host1x_job *job, struct device *dev) int err; unsigned int i, j; struct host1x *host = dev_get_drvdata(dev->parent); - struct host1x_firewall fw; DECLARE_BITMAP(waitchk_mask, host1x_syncpt_nb_pts(host));
- fw.job = job; - fw.dev = dev; - fw.reloc = job->relocarray; - fw.num_relocs = job->num_relocs; - fw.class = 0; - bitmap_zero(waitchk_mask, host1x_syncpt_nb_pts(host)); for (i = 0; i < job->num_waitchk; i++) { u32 syncpt_id = job->waitchk[i].syncpt_id; @@ -536,19 +534,11 @@ int host1x_job_pin(struct host1x_job *job, struct device *dev) if (job->gathers[j].bo == g->bo) job->gathers[j].handled = true;
- err = 0; - - if (IS_ENABLED(CONFIG_TEGRA_HOST1X_FIREWALL)) - err = validate(&fw, g); - + err = do_relocs(job, g->bo); if (err) - dev_err(dev, "Job invalid (err=%d)\n", err); - - if (!err) - err = do_relocs(job, g->bo); + break;
- if (!err) - err = do_waitchks(job, host, g->bo); + err = do_waitchks(job, host, g->bo); if (err) break; }