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authorMikhail Malygin <m.malygin@yadro.com>2020-07-16 22:03:41 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-08-19 09:26:36 +0300
commitb76ca3f373b52c9be3838b703c1976cafe07752e (patch)
treee53f8d6444a2530de0a0dee36986f50b1ed934ea
parentbdb550b1e4205881f7598e32d2fab9133ef0a694 (diff)
downloadlinux-b76ca3f373b52c9be3838b703c1976cafe07752e.tar.xz
RDMA/rxe: Prevent access to wr->next ptr afrer wr is posted to send queue
[ Upstream commit 5f0b2a6093a4d9aab093964c65083fe801ef1e58 ] 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 <m.malygin@yadro.com> Signed-off-by: Sergey Kojushev <s.kojushev@yadro.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
-rw-r--r--drivers/infiniband/sw/rxe/rxe_verbs.c5
1 files changed, 4 insertions, 1 deletions
diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.c b/drivers/infiniband/sw/rxe/rxe_verbs.c
index b8a22af724e8..84fec5fd798d 100644
--- a/drivers/infiniband/sw/rxe/rxe_verbs.c
+++ b/drivers/infiniband/sw/rxe/rxe_verbs.c
@@ -684,6 +684,7 @@ 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);
@@ -700,6 +701,8 @@ 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;
@@ -710,7 +713,7 @@ 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);