From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: suresh kumar <suresh2514@gmail.com>,
"David S . Miller" <davem@davemloft.net>,
Sasha Levin <sashal@kernel.org>,
kuba@kernel.org, atenart@kernel.org, edumazet@google.com,
netdev@vger.kernel.org
Subject: [PATCH AUTOSEL 5.4 03/11] net-sysfs: add check for netdevice being present to speed_show
Date: Tue, 1 Mar 2022 15:19:36 -0500 [thread overview]
Message-ID: <20220301201951.19066-3-sashal@kernel.org> (raw)
In-Reply-To: <20220301201951.19066-1-sashal@kernel.org>
From: suresh kumar <suresh2514@gmail.com>
[ Upstream commit 4224cfd7fb6523f7a9d1c8bb91bb5df1e38eb624 ]
When bringing down the netdevice or system shutdown, a panic can be
triggered while accessing the sysfs path because the device is already
removed.
[ 755.549084] mlx5_core 0000:12:00.1: Shutdown was called
[ 756.404455] mlx5_core 0000:12:00.0: Shutdown was called
...
[ 757.937260] BUG: unable to handle kernel NULL pointer dereference at (null)
[ 758.031397] IP: [<ffffffff8ee11acb>] dma_pool_alloc+0x1ab/0x280
crash> bt
...
PID: 12649 TASK: ffff8924108f2100 CPU: 1 COMMAND: "amsd"
...
#9 [ffff89240e1a38b0] page_fault at ffffffff8f38c778
[exception RIP: dma_pool_alloc+0x1ab]
RIP: ffffffff8ee11acb RSP: ffff89240e1a3968 RFLAGS: 00010046
RAX: 0000000000000246 RBX: ffff89243d874100 RCX: 0000000000001000
RDX: 0000000000000000 RSI: 0000000000000246 RDI: ffff89243d874090
RBP: ffff89240e1a39c0 R8: 000000000001f080 R9: ffff8905ffc03c00
R10: ffffffffc04680d4 R11: ffffffff8edde9fd R12: 00000000000080d0
R13: ffff89243d874090 R14: ffff89243d874080 R15: 0000000000000000
ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018
#10 [ffff89240e1a39c8] mlx5_alloc_cmd_msg at ffffffffc04680f3 [mlx5_core]
#11 [ffff89240e1a3a18] cmd_exec at ffffffffc046ad62 [mlx5_core]
#12 [ffff89240e1a3ab8] mlx5_cmd_exec at ffffffffc046b4fb [mlx5_core]
#13 [ffff89240e1a3ae8] mlx5_core_access_reg at ffffffffc0475434 [mlx5_core]
#14 [ffff89240e1a3b40] mlx5e_get_fec_caps at ffffffffc04a7348 [mlx5_core]
#15 [ffff89240e1a3bb0] get_fec_supported_advertised at ffffffffc04992bf [mlx5_core]
#16 [ffff89240e1a3c08] mlx5e_get_link_ksettings at ffffffffc049ab36 [mlx5_core]
#17 [ffff89240e1a3ce8] __ethtool_get_link_ksettings at ffffffff8f25db46
#18 [ffff89240e1a3d48] speed_show at ffffffff8f277208
#19 [ffff89240e1a3dd8] dev_attr_show at ffffffff8f0b70e3
#20 [ffff89240e1a3df8] sysfs_kf_seq_show at ffffffff8eedbedf
#21 [ffff89240e1a3e18] kernfs_seq_show at ffffffff8eeda596
#22 [ffff89240e1a3e28] seq_read at ffffffff8ee76d10
#23 [ffff89240e1a3e98] kernfs_fop_read at ffffffff8eedaef5
#24 [ffff89240e1a3ed8] vfs_read at ffffffff8ee4e3ff
#25 [ffff89240e1a3f08] sys_read at ffffffff8ee4f27f
#26 [ffff89240e1a3f50] system_call_fastpath at ffffffff8f395f92
crash> net_device.state ffff89443b0c0000
state = 0x5 (__LINK_STATE_START| __LINK_STATE_NOCARRIER)
To prevent this scenario, we also make sure that the netdevice is present.
Signed-off-by: suresh kumar <suresh2514@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/core/net-sysfs.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
index bcad7028bbf45..ad45f13a0370b 100644
--- a/net/core/net-sysfs.c
+++ b/net/core/net-sysfs.c
@@ -212,7 +212,7 @@ static ssize_t speed_show(struct device *dev,
if (!rtnl_trylock())
return restart_syscall();
- if (netif_running(netdev)) {
+ if (netif_running(netdev) && netif_device_present(netdev)) {
struct ethtool_link_ksettings cmd;
if (!__ethtool_get_link_ksettings(netdev, &cmd))
--
2.34.1
next prev parent reply other threads:[~2022-03-01 20:27 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-01 20:19 [PATCH AUTOSEL 5.4 01/11] selftests/bpf: Add test for bpf_timer overwriting crash Sasha Levin
2022-03-01 20:19 ` [PATCH AUTOSEL 5.4 02/11] KVM: Fix lockdep false negative during host resume Sasha Levin
2022-03-01 20:22 ` Paolo Bonzini
2022-03-01 20:19 ` Sasha Levin [this message]
2022-03-01 20:19 ` [PATCH AUTOSEL 5.4 04/11] sr9700: sanity check for packet length Sasha Levin
2022-03-01 20:19 ` [PATCH AUTOSEL 5.4 05/11] gpio: Return EPROBE_DEFER if gc->to_irq is NULL Sasha Levin
2022-03-01 20:19 ` [PATCH AUTOSEL 5.4 06/11] Revert "xen-netback: remove 'hotplug-status' once it has served its purpose" Sasha Levin
2022-03-01 20:19 ` [PATCH AUTOSEL 5.4 07/11] Revert "xen-netback: Check for hotplug-status existence before watching" Sasha Levin
2022-03-01 20:19 ` [PATCH AUTOSEL 5.4 08/11] ipv6: prevent a possible race condition with lifetimes Sasha Levin
2022-03-01 20:19 ` [PATCH AUTOSEL 5.4 09/11] tracing: Ensure trace buffer is at least 4096 bytes large Sasha Levin
2022-03-01 20:19 ` [PATCH AUTOSEL 5.4 10/11] selftest/vm: fix map_fixed_noreplace test failure Sasha Levin
2022-03-01 20:19 ` [PATCH AUTOSEL 5.4 11/11] selftests/memfd: clean up mapping in mfd_fail_write Sasha Levin
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