Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider: - [Medium] drm/msm: 64-to-32-bit truncation in size_add() in vm_bind_job_lookup_ops() --
commit 0bb1fc19abe2c004d338802c56cd54e0621aa9a6 Author: Rob Clark <[email protected]> drm/msm/gem: Fix VM_BIND range check This commit replaces the addition of op->range and op->obj_offset with size_add() in vm_bind_job_lookup_ops() to guard against integer overflow when validating the range against obj->size. > diff --git a/drivers/gpu/drm/msm/msm_gem_vma.c > b/drivers/gpu/drm/msm/msm_gem_vma.c > index f687a629629d3..16b3870d5e90e 100644 > --- a/drivers/gpu/drm/msm/msm_gem_vma.c > +++ b/drivers/gpu/drm/msm/msm_gem_vma.c > @@ -1118,7 +1118,7 @@ vm_bind_job_lookup_ops(struct msm_vm_bind_job *job, > struct drm_msm_vm_bind *args > op->obj = obj; > cnt++; > > - if ((op->range + op->obj_offset) > obj->size) { > + if (size_add(op->range, op->obj_offset) > obj->size) { [Severity: Medium] On 32-bit builds, does passing op->range and op->obj_offset to size_add() truncate the upper 32 bits of both 64-bit operands before checking for overflow? In struct msm_vm_bind_op, obj_offset and range are 64-bit values: drivers/gpu/drm/msm/msm_gem_vma.c: struct msm_vm_bind_op { ... uint64_t obj_offset; uint64_t iova; uint64_t range; ... }; However, size_add() in include/linux/overflow.h takes size_t arguments: static __always_inline size_t __must_check size_add(size_t addend1, size_t addend2) Earlier in lookup_op(), op->obj_offset is only checked with invalid_alignment(op->obj_offset), which does not reject non-zero upper 32 bits. On 32-bit architectures where size_t is 32 bits wide, an offset such as 0x100000000ULL is truncated to 0 when passed to size_add(), allowing an out-of-bounds 64-bit op->obj_offset or op->range to bypass the obj->size check in vm_bind_job_lookup_ops() and be stored into vma->gem.offset. Would check_add_overflow() with a uint64_t sum (or range_overflows_t(u64, op->obj_offset, op->range, obj->size)) avoid narrowing the operands on 32-bit targets? -- Sashiko AI review ยท https://sashiko.dev/#/patchset/[email protected]?part=1
