[PATCH 4.14 150/193] IB/core: Avoid crash on pkey enforcement failed in received MADs

From: Greg Kroah-Hartman
Date: Tue Nov 28 2017 - 05:50:07 EST


4.14-stable review patch. If anyone has any objections, please let me know.

------------------

From: Parav Pandit <parav@xxxxxxxxxxxx>

commit 89548bcafec7ecfeea58c553f0834b5d575a66eb upstream.

Below kernel crash is observed when Pkey security enforcement fails on
received MADs. This issue is reported in [1].

ib_free_recv_mad() accesses the rmpp_list, whose initialization is
needed before accessing it.
When security enformcent fails on received MADs, MAD processing avoided
due to security checks failed.

OpenSM[3770]: SM port is down
kernel: BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
kernel: IP: ib_free_recv_mad+0x44/0xa0 [ib_core]
kernel: PGD 0
kernel: P4D 0
kernel:
kernel: Oops: 0002 [#1] SMP
kernel: CPU: 0 PID: 2833 Comm: kworker/0:1H Tainted: P IO 4.13.4-1-pve #1
kernel: Hardware name: Dell XS23-TY3 /9CMP63, BIOS 1.71 09/17/2013
kernel: Workqueue: ib-comp-wq ib_cq_poll_work [ib_core]
kernel: task: ffffa069c6541600 task.stack: ffffb9a729054000
kernel: RIP: 0010:ib_free_recv_mad+0x44/0xa0 [ib_core]
kernel: RSP: 0018:ffffb9a729057d38 EFLAGS: 00010286
kernel: RAX: ffffa069cb138a48 RBX: ffffa069cb138a10 RCX: 0000000000000000
kernel: RDX: ffffb9a729057d38 RSI: 0000000000000000 RDI: ffffa069cb138a20
kernel: RBP: ffffb9a729057d60 R08: ffffa072d2d49800 R09: ffffa069cb138ae0
kernel: R10: ffffa069cb138ae0 R11: ffffa072b3994e00 R12: ffffb9a729057d38
kernel: R13: ffffa069d1c90000 R14: 0000000000000000 R15: ffffa069d1c90880
kernel: FS: 0000000000000000(0000) GS:ffffa069dba00000(0000) knlGS:0000000000000000
kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
kernel: CR2: 0000000000000008 CR3: 00000011f51f2000 CR4: 00000000000006f0
kernel: Call Trace:
kernel: ib_mad_recv_done+0x5cc/0xb50 [ib_core]
kernel: __ib_process_cq+0x5c/0xb0 [ib_core]
kernel: ib_cq_poll_work+0x20/0x60 [ib_core]
kernel: process_one_work+0x1e9/0x410
kernel: worker_thread+0x4b/0x410
kernel: kthread+0x109/0x140
kernel: ? process_one_work+0x410/0x410
kernel: ? kthread_create_on_node+0x70/0x70
kernel: ? SyS_exit_group+0x14/0x20
kernel: ret_from_fork+0x25/0x30
kernel: RIP: ib_free_recv_mad+0x44/0xa0 [ib_core] RSP: ffffb9a729057d38
kernel: CR2: 0000000000000008

[1] : https://www.spinics.net/lists/linux-rdma/msg56190.html

Fixes: 47a2b338fe63 ("IB/core: Enforce security on management datagrams")
Signed-off-by: Parav Pandit <parav@xxxxxxxxxxxx>
Reported-by: Chris Blake <chrisrblake93@xxxxxxxxx>
Reviewed-by: Daniel Jurgens <danielj@xxxxxxxxxxxx>
Reviewed-by: Hal Rosenstock <hal@xxxxxxxxxxxx>
Signed-off-by: Doug Ledford <dledford@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/infiniband/core/mad.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/infiniband/core/mad.c
+++ b/drivers/infiniband/core/mad.c
@@ -1974,14 +1974,15 @@ static void ib_mad_complete_recv(struct
unsigned long flags;
int ret;

+ INIT_LIST_HEAD(&mad_recv_wc->rmpp_list);
ret = ib_mad_enforce_security(mad_agent_priv,
mad_recv_wc->wc->pkey_index);
if (ret) {
ib_free_recv_mad(mad_recv_wc);
deref_mad_agent(mad_agent_priv);
+ return;
}

- INIT_LIST_HEAD(&mad_recv_wc->rmpp_list);
list_add(&mad_recv_wc->recv_buf.list, &mad_recv_wc->rmpp_list);
if (ib_mad_kernel_rmpp_agent(&mad_agent_priv->agent)) {
mad_recv_wc = ib_process_rmpp_recv_wc(mad_agent_priv,