Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
Pre-existing issues: - [High] NULL pointer dereference from direct access to `ctx->vm` before VM initialization. -- --- Patch [6]: [PATCH v7 06/17] drm/msm: Remove redundant SIZE_MAX check --- commit 704799112fb8f5dd4e2424f4cac69e1d4b373f9d Author: Rob Clark <[email protected]> drm/msm: Remove redundant SIZE_MAX check This commit removes a redundant SIZE_MAX overflow check in submit_lookup_cmds(). Since kmalloc() will inherently fail and return NULL when passed SIZE_MAX, the explicit check is unnecessary. > diff --git a/drivers/gpu/drm/msm/msm_gem_submit.c > b/drivers/gpu/drm/msm/msm_gem_submit.c > index aa48ea4e7f584..040354ee16d11 100644 > --- a/drivers/gpu/drm/msm/msm_gem_submit.c > +++ b/drivers/gpu/drm/msm/msm_gem_submit.c > @@ -250,11 +250,6 @@ static int submit_lookup_cmds(struct msm_gem_submit > *submit, > > sz = array_size(submit_cmd.nr_relocs, > sizeof(struct drm_msm_gem_submit_reloc)); > - /* check for overflow: */ > - if (sz == SIZE_MAX) { > - ret = -ENOMEM; > - goto out; > - } > submit->cmd[i].relocs = kmalloc(sz, GFP_KERNEL | __GFP_NOWARN); > if (!submit->cmd[i].relocs) { > ret = -ENOMEM; [Severity: High] This is a pre-existing issue, but I noticed it while reviewing this file. Can this code cause a NULL pointer dereference if a local user opens a DRM context and immediately calls the GEM submit ioctl before any VM has been created for that context? Looking at msm_ioctl_gem_submit() in the same file: drivers/gpu/drm/msm/msm_gem_submit.c:msm_ioctl_gem_submit() { ... if (args->pad) return -EINVAL; if (to_msm_vm(ctx->vm)->unusable) return UERR(EPIPE, dev, "context is unusable"); ... } The to_msm_vm() macro performs a container_of() calculation, which on a NULL ctx->vm yields an invalid pointer offset. Dereferencing ->unusable on this invalid pointer will cause a page fault. Should this use msm_context_vm(dev, ctx) instead of accessing ctx->vm directly to ensure the VM is properly initialized before checking its unusable state? -- Sashiko AI review ยท https://sashiko.dev/#/patchset/[email protected]?part=6
