accel/rocket: fix NULL dereference and integer overflow in rocket_job_push()

rocket_job_push() allocates a temporary array to hold all input and
output GEM object pointers:

    bos = kvmalloc_array(job->in_bo_count + job->out_bo_count,
                         sizeof(void *), GFP_KERNEL);
    memcpy(bos, job->in_bos, job->in_bo_count * sizeof(void *));
    memcpy(&bos[job->in_bo_count], job->out_bos, ...);

Two bugs exist:

1. Missing NULL check: if kvmalloc_array() fails, bos is NULL and
   the subsequent memcpy() dereferences it, causing a kernel NULL
   pointer dereference.

2. Integer overflow: in_bo_count and out_bo_count are both u32, set
   directly from userspace-supplied in_bo_handle_count and
   out_bo_handle_count with no prior validation. Their sum is computed
   in u32 arithmetic and can wrap to a smaller value, causing the
   allocation count passed to kvmalloc_array() to be smaller than
   intended. Subsequent uses still operate on the original counts when
   copying and locking objects, which may lead to out-of-bounds accesses
   on the temporary array.

Fix by using check_add_overflow() to detect count overflow before the
allocation, and adding a NULL check on the allocation result.

Fixes: 0810d5ad88a1 ("accel/rocket: Add job submission IOCTL")
Cc: stable@vger.kernel.org
Signed-off-by: Muhammad Bilal <meatuni001@gmail.com>
Link: https://lore.kernel.org/r/20260524155716.90955-1-meatuni001@gmail.com
Signed-off-by: Tomeu Vizoso <tomeu@tomeuvizoso.net>

0 files changed, 0 insertions, 0 deletions