From: Saeed Mahameed <saeed@kernel.org>
To: "David S. Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
Eric Dumazet <edumazet@google.com>
Cc: Saeed Mahameed <saeedm@nvidia.com>,
netdev@vger.kernel.org, Eli Cohen <elic@nvidia.com>,
Maor Dickman <maord@nvidia.com>, Mark Bloch <mbloch@nvidia.com>
Subject: [net 02/13] net/mlx5: LAG, fix logic over MLX5_LAG_FLAG_NDEVS_READY
Date: Mon, 22 Aug 2022 12:59:06 -0700 [thread overview]
Message-ID: <20220822195917.216025-3-saeed@kernel.org> (raw)
In-Reply-To: <20220822195917.216025-1-saeed@kernel.org>
From: Eli Cohen <elic@nvidia.com>
Only set MLX5_LAG_FLAG_NDEVS_READY if both netdevices are registered.
Doing so guarantees that both ldev->pf[MLX5_LAG_P0].dev and
ldev->pf[MLX5_LAG_P1].dev have valid pointers when
MLX5_LAG_FLAG_NDEVS_READY is set.
The core issue is asymmetry in setting MLX5_LAG_FLAG_NDEVS_READY and
clearing it. Setting it is done wrongly when both
ldev->pf[MLX5_LAG_P0].dev and ldev->pf[MLX5_LAG_P1].dev are set;
clearing it is done right when either of ldev->pf[i].netdev is cleared.
Consider the following scenario:
1. PF0 loads and sets ldev->pf[MLX5_LAG_P0].dev to a valid pointer
2. PF1 loads and sets both ldev->pf[MLX5_LAG_P1].dev and
ldev->pf[MLX5_LAG_P1].netdev with valid pointers. This results in
MLX5_LAG_FLAG_NDEVS_READY is set.
3. PF0 is unloaded before setting dev->pf[MLX5_LAG_P0].netdev.
MLX5_LAG_FLAG_NDEVS_READY remains set.
Further execution of mlx5_do_bond() will result in null pointer
dereference when calling mlx5_lag_is_multipath()
This patch fixes the following call trace actually encountered:
[ 1293.475195] BUG: kernel NULL pointer dereference, address: 00000000000009a8
[ 1293.478756] #PF: supervisor read access in kernel mode
[ 1293.481320] #PF: error_code(0x0000) - not-present page
[ 1293.483686] PGD 0 P4D 0
[ 1293.484434] Oops: 0000 [#1] SMP PTI
[ 1293.485377] CPU: 1 PID: 23690 Comm: kworker/u16:2 Not tainted 5.18.0-rc5_for_upstream_min_debug_2022_05_05_10_13 #1
[ 1293.488039] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
[ 1293.490836] Workqueue: mlx5_lag mlx5_do_bond_work [mlx5_core]
[ 1293.492448] RIP: 0010:mlx5_lag_is_multipath+0x5/0x50 [mlx5_core]
[ 1293.494044] Code: e8 70 40 ff e0 48 8b 14 24 48 83 05 5c 1a 1b 00 01 e9 19 ff ff ff 48 83 05 47 1a 1b 00 01 eb d7 0f 1f 44 00 00 0f 1f 44 00 00 <48> 8b 87 a8 09 00 00 48 85 c0 74 26 48 83 05 a7 1b 1b 00 01 41 b8
[ 1293.498673] RSP: 0018:ffff88811b2fbe40 EFLAGS: 00010202
[ 1293.500152] RAX: ffff88818a94e1c0 RBX: ffff888165eca6c0 RCX: 0000000000000000
[ 1293.501841] RDX: 0000000000000001 RSI: ffff88818a94e1c0 RDI: 0000000000000000
[ 1293.503585] RBP: 0000000000000000 R08: ffff888119886740 R09: ffff888165eca73c
[ 1293.505286] R10: 0000000000000018 R11: 0000000000000018 R12: ffff88818a94e1c0
[ 1293.506979] R13: ffff888112729800 R14: 0000000000000000 R15: ffff888112729858
[ 1293.508753] FS: 0000000000000000(0000) GS:ffff88852cc40000(0000) knlGS:0000000000000000
[ 1293.510782] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1293.512265] CR2: 00000000000009a8 CR3: 00000001032d4002 CR4: 0000000000370ea0
[ 1293.514001] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 1293.515806] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Fixes: 8a66e4585979 ("net/mlx5: Change ownership model for lag")
Signed-off-by: Eli Cohen <elic@nvidia.com>
Reviewed-by: Maor Dickman <maord@nvidia.com>
Reviewed-by: Mark Bloch <mbloch@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
---
drivers/net/ethernet/mellanox/mlx5/core/lag/lag.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/lag/lag.c b/drivers/net/ethernet/mellanox/mlx5/core/lag/lag.c
index 0f34e3c80d1f..f67d29164962 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/lag/lag.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/lag/lag.c
@@ -1234,7 +1234,7 @@ void mlx5_lag_add_netdev(struct mlx5_core_dev *dev,
mlx5_ldev_add_netdev(ldev, dev, netdev);
for (i = 0; i < ldev->ports; i++)
- if (!ldev->pf[i].dev)
+ if (!ldev->pf[i].netdev)
break;
if (i >= ldev->ports)
--
2.37.1
next prev parent reply other threads:[~2022-08-22 20:00 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-22 19:59 [pull request][net 00/13] mlx5 fixes 2022-08-22 Saeed Mahameed
2022-08-22 19:59 ` [net 01/13] net/mlx5e: Properly disable vlan strip on non-UL reps Saeed Mahameed
2022-08-24 1:00 ` patchwork-bot+netdevbpf
2022-08-22 19:59 ` Saeed Mahameed [this message]
2022-08-22 19:59 ` [net 03/13] net/mlx5: Eswitch, Fix forwarding decision to uplink Saeed Mahameed
2022-08-22 19:59 ` [net 04/13] net/mlx5: Disable irq when locking lag_lock Saeed Mahameed
2022-08-22 19:59 ` [net 05/13] net/mlx5: Fix cmd error logging for manage pages cmd Saeed Mahameed
2022-08-22 19:59 ` [net 06/13] net/mlx5: Avoid false positive lockdep warning by adding lock_class_key Saeed Mahameed
2022-08-22 19:59 ` [net 07/13] net/mlx5e: Fix wrong application of the LRO state Saeed Mahameed
2022-08-22 19:59 ` [net 08/13] net/mlx5e: TC, Add missing policer validation Saeed Mahameed
2022-08-22 19:59 ` [net 09/13] net/mlx5e: Fix wrong tc flag used when set hw-tc-offload off Saeed Mahameed
2022-08-22 19:59 ` [net 10/13] net/mlx5: unlock on error path in esw_vfs_changed_event_handler() Saeed Mahameed
2022-08-22 19:59 ` [net 11/13] net/mlx5e: kTLS, Use _safe() iterator in mlx5e_tls_priv_tx_list_cleanup() Saeed Mahameed
2022-08-22 19:59 ` [net 12/13] net/mlx5e: Fix use after free in mlx5e_fs_init() Saeed Mahameed
2022-08-22 19:59 ` [net 13/13] net/mlx5: Unlock on error in mlx5_sriov_enable() Saeed Mahameed
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