net: stmmac: enable all safety features by default
authorAndrew Halaney <ahalaney@redhat.com>
Wed, 18 Jan 2023 16:56:38 +0000 (10:56 -0600)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 1 Feb 2023 07:27:15 +0000 (08:27 +0100)
commit120b8e527e07c65de7f2b9018dcd9d17e66f2427
tree05a993776d7a377b63e89a91bea68f7e2993b2a3
parenta7d736cc3c6cb0d7498bbfb56515d414e35e9510
net: stmmac: enable all safety features by default

[ Upstream commit fdfc76a116b5e9d3e98e6c96fe83b42d011d21d4 ]

In the original implementation of dwmac5
commit 8bf993a5877e ("net: stmmac: Add support for DWMAC5 and implement Safety Features")
all safety features were enabled by default.

Later it seems some implementations didn't have support for all the
features, so in
commit 5ac712dcdfef ("net: stmmac: enable platform specific safety features")
the safety_feat_cfg structure was added to the callback and defined for
some platforms to selectively enable these safety features.

The problem is that only certain platforms were given that software
support. If the automotive safety package bit is set in the hardware
features register the safety feature callback is called for the platform,
and for platforms that didn't get a safety_feat_cfg defined this results
in the following NULL pointer dereference:

[    7.933303] Call trace:
[    7.935812]  dwmac5_safety_feat_config+0x20/0x170 [stmmac]
[    7.941455]  __stmmac_open+0x16c/0x474 [stmmac]
[    7.946117]  stmmac_open+0x38/0x70 [stmmac]
[    7.950414]  __dev_open+0x100/0x1dc
[    7.954006]  __dev_change_flags+0x18c/0x204
[    7.958297]  dev_change_flags+0x24/0x6c
[    7.962237]  do_setlink+0x2b8/0xfa4
[    7.965827]  __rtnl_newlink+0x4ec/0x840
[    7.969766]  rtnl_newlink+0x50/0x80
[    7.973353]  rtnetlink_rcv_msg+0x12c/0x374
[    7.977557]  netlink_rcv_skb+0x5c/0x130
[    7.981500]  rtnetlink_rcv+0x18/0x2c
[    7.985172]  netlink_unicast+0x2e8/0x340
[    7.989197]  netlink_sendmsg+0x1a8/0x420
[    7.993222]  ____sys_sendmsg+0x218/0x280
[    7.997249]  ___sys_sendmsg+0xac/0x100
[    8.001103]  __sys_sendmsg+0x84/0xe0
[    8.004776]  __arm64_sys_sendmsg+0x24/0x30
[    8.008983]  invoke_syscall+0x48/0x114
[    8.012840]  el0_svc_common.constprop.0+0xcc/0xec
[    8.017665]  do_el0_svc+0x38/0xb0
[    8.021071]  el0_svc+0x2c/0x84
[    8.024212]  el0t_64_sync_handler+0xf4/0x120
[    8.028598]  el0t_64_sync+0x190/0x194

Go back to the original behavior, if the automotive safety package
is found to be supported in hardware enable all the features unless
safety_feat_cfg is passed in saying this particular platform only
supports a subset of the features.

Fixes: 5ac712dcdfef ("net: stmmac: enable platform specific safety features")
Reported-by: Ning Cai <ncai@quicinc.com>
Signed-off-by: Andrew Halaney <ahalaney@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
drivers/net/ethernet/stmicro/stmmac/dwmac5.c