Re: [PATCH V2][5.15.y] bnxt_re: avoid shift undefined behavior in bnxt_qplib_alloc_init_hwq

[Sasha Levin <sashal@kernel.org>]

[ Sasha's backport helper bot ]

Hi,

The upstream commit SHA1 provided is correct: 78cfd17142ef70599d6409cbd709d94b3da58659

WARNING: Author mismatch between patch and upstream commit:
Backport author: guocai.he.cn@windriver.com
Commit author: Michal Schmidt <mschmidt@redhat.com>


Status in newer kernel trees:
6.12.y | Present (exact SHA1)
6.6.y | Present (different SHA1: a658f011d89d)
6.1.y | Present (different SHA1: 84d2f2915218)
5.15.y | Not found

Note: The patch differs from the upstream commit:
---
1:  78cfd17142ef7 ! 1:  b6bf18a2edb26 bnxt_re: avoid shift undefined behavior in bnxt_qplib_alloc_init_hwq
    @@ Metadata
      ## Commit message ##
         bnxt_re: avoid shift undefined behavior in bnxt_qplib_alloc_init_hwq
     
    +    commit 78cfd17142ef70599d6409cbd709d94b3da58659 upstream.
    +
         Undefined behavior is triggered when bnxt_qplib_alloc_init_hwq is called
         with hwq_attr->aux_depth != 0 and hwq_attr->aux_stride == 0.
         In that case, "roundup_pow_of_two(hwq_attr->aux_stride)" gets called.
    @@ Commit message
         Link: https://lore.kernel.org/r/20240507103929.30003-1-mschmidt@redhat.com
         Acked-by: Selvin Xavier <selvin.xavier@broadcom.com>
         Signed-off-by: Leon Romanovsky <leon@kernel.org>
    +    Signed-off-by: Xiangyu Chen <xiangyu.chen@windriver.com>
    +    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
    +    Signed-off-by: Guocai He <guocai.he.cn@windriver.com>
     
      ## drivers/infiniband/hw/bnxt_re/qplib_fp.c ##
     @@ drivers/infiniband/hw/bnxt_re/qplib_fp.c: int bnxt_qplib_create_qp(struct bnxt_qplib_res *res, struct bnxt_qplib_qp *qp)
    @@ drivers/infiniband/hw/bnxt_re/qplib_fp.c: int bnxt_qplib_create_qp(struct bnxt_q
     -	hwq_attr.aux_depth = bnxt_qplib_set_sq_size(sq, qp->wqe_mode);
     +	hwq_attr.aux_depth = psn_sz ? bnxt_qplib_set_sq_size(sq, qp->wqe_mode)
     +				    : 0;
    - 	/* Update msn tbl size */
    - 	if (BNXT_RE_HW_RETX(qp->dev_cap_flags) && psn_sz) {
    - 		hwq_attr.aux_depth = roundup_pow_of_two(bnxt_qplib_set_sq_size(sq, qp->wqe_mode));
    + 	hwq_attr.type = HWQ_TYPE_QUEUE;
    + 	rc = bnxt_qplib_alloc_init_hwq(&sq->hwq, &hwq_attr);
    + 	if (rc)
---

Results of testing on various branches:

| Branch                    | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| stable/linux-5.15.y       |  Success    |  Success   |