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,