From: Maor Gottlieb maorg@mellanox.com
[ Upstream commit 189277f3814c36133f4ff0352f4b5194a38486b6 ]
q_deferred_work isn't initialized when creating an explicit ODP memory region. This can lead to a NULL pointer dereference when user performs asynchronous prefetch MR. Fix it by initializing q_deferred_work for explicit ODP.
BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: 0000 [#1] SMP PTI CPU: 4 PID: 6074 Comm: kworker/u16:6 Not tainted 5.7.0-rc1-for-upstream-perf-2020-04-17_07-03-39-64 #1 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014 Workqueue: events_unbound mlx5_ib_prefetch_mr_work [mlx5_ib] RIP: 0010:__wake_up_common+0x49/0x120 Code: 04 89 54 24 0c 89 4c 24 08 74 0a 41 f6 01 04 0f 85 8e 00 00 00 48 8b 47 08 48 83 e8 18 4c 8d 67 08 48 8d 50 18 49 39 d4 74 66 <48> 8b 70 18 31 db 4c 8d 7e e8 eb 17 49 8b 47 18 48 8d 50 e8 49 8d RSP: 0000:ffffc9000097bd88 EFLAGS: 00010082 RAX: ffffffffffffffe8 RBX: ffff888454cd9f90 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000003 RDI: ffff888454cd9f90 RBP: ffffc9000097bdd0 R08: 0000000000000000 R09: ffffc9000097bdd0 R10: 0000000000000000 R11: 0000000000000001 R12: ffff888454cd9f98 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000003 FS: 0000000000000000(0000) GS:ffff88846fd00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000044c19e002 CR4: 0000000000760ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: __wake_up_common_lock+0x7a/0xc0 destroy_prefetch_work+0x5a/0x60 [mlx5_ib] mlx5_ib_prefetch_mr_work+0x64/0x80 [mlx5_ib] process_one_work+0x15b/0x360 worker_thread+0x49/0x3d0 kthread+0xf5/0x130 ? rescuer_thread+0x310/0x310 ? kthread_bind+0x10/0x10 ret_from_fork+0x1f/0x30
Fixes: de5ed007a03d ("IB/mlx5: Fix implicit ODP race") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20200521072504.567406-1-leon@kernel.org Signed-off-by: Maor Gottlieb maorg@mellanox.com Signed-off-by: Leon Romanovsky leonro@mellanox.com Signed-off-by: Jason Gunthorpe jgg@mellanox.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/infiniband/hw/mlx5/mr.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/drivers/infiniband/hw/mlx5/mr.c b/drivers/infiniband/hw/mlx5/mr.c index 6fa0a83c19de..9a1747a97fb6 100644 --- a/drivers/infiniband/hw/mlx5/mr.c +++ b/drivers/infiniband/hw/mlx5/mr.c @@ -1319,6 +1319,7 @@ struct ib_mr *mlx5_ib_reg_user_mr(struct ib_pd *pd, u64 start, u64 length,
if (is_odp_mr(mr)) { to_ib_umem_odp(mr->umem)->private = mr; + init_waitqueue_head(&mr->q_deferred_work); atomic_set(&mr->num_deferred_work, 0); err = xa_err(xa_store(&dev->odp_mkeys, mlx5_base_mkey(mr->mmkey.key), &mr->mmkey,