[PATCH 5.12 072/178] net/mlx5: Check that driver was probed prior attaching the device

Greg Kroah-Hartman
2021-06-21T16:43:47Z

From: Leon Romanovsky <leonro@nvidia.com>

[ Upstream commit 2058cc9c8041fde9c0bdd8e868c72b137cff8563 ]

The device can be requested to be attached despite being not probed.
This situation is possible if devlink reload races with module removal,
and the following kernel panic is an outcome of such race.

mlx5_core 0000:00:09.0: firmware version: 4.7.9999
mlx5_core 0000:00:09.0: 0.000 Gb/s available PCIe bandwidth (8.0 GT/s PCIe x255 link)
BUG: unable to handle page fault for address: fffffffffffffff0
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 3218067 P4D 3218067 PUD 321a067 PMD 0
Oops: 0000 [#1] SMP KASAN NOPTI
CPU: 7 PID: 250 Comm: devlink Not tainted 5.12.0-rc2+ #2836
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
RIP: 0010:mlx5_attach_device+0x80/0x280 [mlx5_core]
Code: f8 48 c1 e8 03 42 80 3c 38 00 0f 85 80 01 00 00 48 8b 45 68 48 8d 78 f0 48 89 fe 48 c1 ee 03 42 80 3c 3e 00 0f 85 70 01 00 00 <48> 8b 40 f0 48 85 c0 74 0d 48 89 ef ff d0 85 c0 0f 85 84 05 0e 00
RSP: 0018:ffff8880129675f0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff827407f1
RDX: 1ffff110011336cf RSI: 1ffffffffffffffe RDI: fffffffffffffff0
RBP: ffff888008e0c000 R08: 0000000000000008 R09: ffffffffa0662ee7
R10: fffffbfff40cc5dc R11: 0000000000000000 R12: ffff88800ea002e0
R13: ffffed1001d459f7 R14: ffffffffa05ef4f8 R15: dffffc0000000000
FS: 00007f51dfeaf740(0000) GS:ffff88806d5c0000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffffffffffffff0 CR3: 000000000bc82006 CR4: 0000000000370ea0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
mlx5_load_one+0x117/0x1d0 [mlx5_core]
devlink_reload+0x2d5/0x520
? devlink_remote_reload_actions_performed+0x30/0x30
? mutex_trylock+0x24b/0x2d0
? devlink_nl_cmd_reload+0x62b/0x1070
devlink_nl_cmd_reload+0x66d/0x1070
? devlink_reload+0x520/0x520
? devlink_nl_pre_doit+0x64/0x4d0
genl_family_rcv_msg_doit+0x1e9/0x2f0
? mutex_lock_io_nested+0x1130/0x1130
? genl_family_rcv_msg_attrs_parse.constprop.0+0x240/0x240
? security_capable+0x51/0x90
genl_rcv_msg+0x27f/0x4a0
? genl_get_cmd+0x3c0/0x3c0
? lock_acquire+0x1a9/0x6d0
? devlink_reload+0x520/0x520
? lock_release+0x6c0/0x6c0
netlink_rcv_skb+0x11d/0x340
? genl_get_cmd+0x3c0/0x3c0
? netlink_ack+0x9f0/0x9f0
? lock_release+0x1f9/0x6c0
genl_rcv+0x24/0x40
netlink_unicast+0x433/0x700
? netlink_attachskb+0x730/0x730
? _copy_from_iter_full+0x178/0x650
? __alloc_skb+0x113/0x2b0
netlink_sendmsg+0x6f1/0xbd0
? netlink_unicast+0x700/0x700
? netlink_unicast+0x700/0x700
sock_sendmsg+0xb0/0xe0
__sys_sendto+0x193/0x240
? __x64_sys_getpeername+0xb0/0xb0
? copy_page_range+0x2300/0x2300
? __up_read+0x1a1/0x7b0
? do_user_addr_fault+0x219/0xdc0
__x64_sys_sendto+0xdd/0x1b0
? syscall_enter_from_user_mode+0x1d/0x50
do_syscall_64+0x2d/0x40
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f51dffb514a
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb b8 0f 1f 00 f3 0f 1e fa 41 89 ca 64 8b 04 25 18 00 00 00 85 c0 75 15 b8 2c 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 76 c3 0f 1f 44 00 00 55 48 83 ec 30 44 89 4c
RSP: 002b:00007ffcaef22e78 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f51dffb514a
RDX: 0000000000000030 RSI: 000055750daf2440 RDI: 0000000000000003
RBP: 000055750daf2410 R08: 00007f51e0081200 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
Modules linked in: mlx5_core(-) ptp pps_core ib_ipoib rdma_ucm rdma_cm iw_cm ib_cm ib_umad ib_uverbs ib_core [last unloaded: mlx5_ib]
CR2: fffffffffffffff0
---[ end trace 7789831bfe74fa42 ]---

Fixes: a925b5e309c9 ("net/mlx5: Register mlx5 devices to auxiliary virtual bus")
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Reviewed-by: Parav Pandit <parav@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/mellanox/mlx5/core/dev.c | 15 +++++++++++++++
1 file changed, 15 insertions(+)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/dev.c b/drivers/net/ethernet/mellanox/mlx5/core/dev.c
index 9153c9bda96f..f0623e94716b 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/dev.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/dev.c
@@ -323,6 +323,16 @@ int mlx5_attach_device(struct mlx5_core_dev *dev)
}
} else {
adev = &priv->adev[i]->adev;
+
+ /* Pay attention that this is not PCI driver that
+ * mlx5_core_dev is connected, but auxiliary driver.
+ *
+ * Here we can race of module unload with devlink
+ * reload, but we don't need to take extra lock because
+ * we are holding global mlx5_intf_mutex.
+ */
+ if (!adev->dev.driver)
+ continue;
adrv = to_auxiliary_drv(adev->dev.driver);

if (adrv->resume)
@@ -353,6 +363,10 @@ void mlx5_detach_device(struct mlx5_core_dev *dev)
continue;

adev = &priv->adev[i]->adev;
+ /* Auxiliary driver was unbind manually through sysfs */
+ if (!adev->dev.driver)
+ goto skip_suspend;
+
adrv = to_auxiliary_drv(adev->dev.driver);

if (adrv->suspend) {
@@ -360,6 +374,7 @@ void mlx5_detach_device(struct mlx5_core_dev *dev)
continue;
}

+skip_suspend:
del_adev(&priv->adev[i]->adev);
priv->adev[i] = NULL;
}
--
2.30.2