guestdbg.c utilizes memdup_user() to copy a userspace array. This,
currently, does not check for an overflow.
Use the new wrapper memdup_array_user() to copy the array more safely.
Note, KVM explicitly checks the number of entries before duplicating the
array, i.e. adding the overflow check should be a glorified nop.
Suggested-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Philipp Stanner <pstanner@redhat.com>
Acked-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Link: https://lore.kernel.org/r/20231102181526.43279-3-pstanner@redhat.com
[sean: call out that KVM pre-checks the number of entries]
Signed-off-by: Sean Christopherson <seanjc@google.com>
else if (dbg->arch.nr_hw_bp > MAX_BP_COUNT)
return -EINVAL;
- bp_data = memdup_user(dbg->arch.hw_bp,
- sizeof(*bp_data) * dbg->arch.nr_hw_bp);
+ bp_data = memdup_array_user(dbg->arch.hw_bp, dbg->arch.nr_hw_bp,
+ sizeof(*bp_data));
if (IS_ERR(bp_data))
return PTR_ERR(bp_data);