From: Mikhail Malygin Date: Thu, 16 Jul 2020 19:03:41 +0000 (+0300) Subject: RDMA/rxe: Prevent access to wr->next ptr afrer wr is posted to send queue X-Git-Tag: v5.9-rc1~117^2~50 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=5f0b2a6093a4d9aab093964c65083fe801ef1e58;p=thirdparty%2Flinux.git RDMA/rxe: Prevent access to wr->next ptr afrer wr is posted to send queue rxe_post_send_kernel() iterates over linked list of wr's, until the wr->next ptr is NULL. However if we've got an interrupt after last wr is posted, control may be returned to the code after send completion callback is executed and wr memory is freed. As a result, wr->next pointer may contain incorrect value leading to panic. Store the wr->next on the stack before posting it. Fixes: 8700e3e7c485 ("Soft RoCE driver") Link: https://lore.kernel.org/r/20200716190340.23453-1-m.malygin@yadro.com Signed-off-by: Mikhail Malygin Signed-off-by: Sergey Kojushev Signed-off-by: Jason Gunthorpe --- diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.c b/drivers/infiniband/sw/rxe/rxe_verbs.c index 74f071003690a..c1649aec8c23d 100644 --- a/drivers/infiniband/sw/rxe/rxe_verbs.c +++ b/drivers/infiniband/sw/rxe/rxe_verbs.c @@ -682,6 +682,7 @@ static int rxe_post_send_kernel(struct rxe_qp *qp, const struct ib_send_wr *wr, unsigned int mask; unsigned int length = 0; int i; + struct ib_send_wr *next; while (wr) { mask = wr_opcode_mask(wr->opcode, qp); @@ -698,6 +699,8 @@ static int rxe_post_send_kernel(struct rxe_qp *qp, const struct ib_send_wr *wr, break; } + next = wr->next; + length = 0; for (i = 0; i < wr->num_sge; i++) length += wr->sg_list[i].length; @@ -708,7 +711,7 @@ static int rxe_post_send_kernel(struct rxe_qp *qp, const struct ib_send_wr *wr, *bad_wr = wr; break; } - wr = wr->next; + wr = next; } rxe_run_task(&qp->req.task, 1);