On Wed, Aug 28, 2024 at 12:08 AM Dragos Tatulea <dtatulea@xxxxxxxxxx> wrote:
>
> Certain error paths from mlx5_vdpa_dev_add() can end up releasing mr
> resources which never got initialized in the first place.
>
> This patch adds the missing check in mlx5_vdpa_destroy_mr_resources()
> to block releasing non-initialized mr resources.
>
> Reference trace:
>
> mlx5_core 0000:08:00.2: mlx5_vdpa_dev_add:3274:(pid 2700) warning: No mac address provisioned?
> BUG: kernel NULL pointer dereference, address: 0000000000000000
> #PF: supervisor read access in kernel mode
> #PF: error_code(0x0000) - not-present page
> PGD 140216067 P4D 0
> Oops: 0000 [#1] PREEMPT SMP NOPTI
> CPU: 8 PID: 2700 Comm: vdpa Kdump: loaded Not tainted 5.14.0-496.el9.x86_64 #1
> Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
> RIP: 0010:vhost_iotlb_del_range+0xf/0xe0 [vhost_iotlb]
> Code: [...]
> RSP: 0018:ff1c823ac23077f0 EFLAGS: 00010246
> RAX: ffffffffc1a21a60 RBX: ffffffff899567a0 RCX: 0000000000000000
> RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 0000000000000000
> RBP: ff1bda1f7c21e800 R08: 0000000000000000 R09: ff1c823ac2307670
> R10: ff1c823ac2307668 R11: ffffffff8a9e7b68 R12: 0000000000000000
> R13: 0000000000000000 R14: ff1bda1f43e341a0 R15: 00000000ffffffea
> FS: 00007f56eba7c740(0000) GS:ff1bda269f800000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 0000000000000000 CR3: 0000000104d90001 CR4: 0000000000771ef0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> PKRU: 55555554
> Call Trace:
>
> ? show_trace_log_lvl+0x1c4/0x2df
> ? show_trace_log_lvl+0x1c4/0x2df
> ? mlx5_vdpa_free+0x3d/0x150 [mlx5_vdpa]
> ? __die_body.cold+0x8/0xd
> ? page_fault_oops+0x134/0x170
> ? __irq_work_queue_local+0x2b/0xc0
> ? irq_work_queue+0x2c/0x50
> ? exc_page_fault+0x62/0x150
> ? asm_exc_page_fault+0x22/0x30
> ? __pfx_mlx5_vdpa_free+0x10/0x10 [mlx5_vdpa]
> ? vhost_iotlb_del_range+0xf/0xe0 [vhost_iotlb]
> mlx5_vdpa_free+0x3d/0x150 [mlx5_vdpa]
> vdpa_release_dev+0x1e/0x50 [vdpa]
> device_release+0x31/0x90
> kobject_cleanup+0x37/0x130
> mlx5_vdpa_dev_add+0x2d2/0x7a0 [mlx5_vdpa]
> vdpa_nl_cmd_dev_add_set_doit+0x277/0x4c0 [vdpa]
> genl_family_rcv_msg_doit+0xd9/0x130
> genl_family_rcv_msg+0x14d/0x220
> ? __pfx_vdpa_nl_cmd_dev_add_set_doit+0x10/0x10 [vdpa]
> ? _copy_to_user+0x1a/0x30
> ? move_addr_to_user+0x4b/0xe0
> genl_rcv_msg+0x47/0xa0
> ? __import_iovec+0x46/0x150
> ? __pfx_genl_rcv_msg+0x10/0x10
> netlink_rcv_skb+0x54/0x100
> genl_rcv+0x24/0x40
> netlink_unicast+0x245/0x370
> netlink_sendmsg+0x206/0x440
> __sys_sendto+0x1dc/0x1f0
> ? do_read_fault+0x10c/0x1d0
> ? do_pte_missing+0x10d/0x190
> __x64_sys_sendto+0x20/0x30
> do_syscall_64+0x5c/0xf0
> ? __count_memcg_events+0x4f/0xb0
> ? mm_account_fault+0x6c/0x100
> ? handle_mm_fault+0x116/0x270
> ? do_user_addr_fault+0x1d6/0x6a0
> ? do_syscall_64+0x6b/0xf0
> ? clear_bhb_loop+0x25/0x80
> ? clear_bhb_loop+0x25/0x80
> ? clear_bhb_loop+0x25/0x80
> ? clear_bhb_loop+0x25/0x80
> ? clear_bhb_loop+0x25/0x80
> entry_SYSCALL_64_after_hwframe+0x78/0x80
>
> Fixes: 512c0cdd80c1 ("vdpa/mlx5: Decouple cvq iotlb handling from hw mapping code")
> Signed-off-by: Dragos Tatulea <dtatulea@xxxxxxxxxx>
> Reviewed-by: Cosmin Ratiu <cratiu@xxxxxxxxxx>
Acked-by: Jason Wang <jasowang@xxxxxxxxxx>
Thanks
> ---
> drivers/vdpa/mlx5/core/mr.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/drivers/vdpa/mlx5/core/mr.c b/drivers/vdpa/mlx5/core/mr.c
> index 4758914ccf86..bf56f3d69625 100644
> --- a/drivers/vdpa/mlx5/core/mr.c
> +++ b/drivers/vdpa/mlx5/core/mr.c
> @@ -581,6 +581,9 @@ static void mlx5_vdpa_show_mr_leaks(struct mlx5_vdpa_dev *mvdev)
>
> void mlx5_vdpa_destroy_mr_resources(struct mlx5_vdpa_dev *mvdev)
> {
> + if (!mvdev->res.valid)
> + return;
> +
> for (int i = 0; i < MLX5_VDPA_NUM_AS; i++)
> mlx5_vdpa_update_mr(mvdev, NULL, i);
>
> --
> 2.45.1
>
