The patch below does not apply to the 5.10-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 82a44ae113b7b35850f4542f0443fcab221e376a Mon Sep 17 00:00:00 2001
From: Wong Vee Khee <vee.khee.wong@xxxxxxxxxxxxxxx>
Date: Fri, 20 Aug 2021 21:26:22 +0800
Subject: [PATCH] net: stmmac: fix kernel panic due to NULL pointer dereference
of plat->est
In the case of taprio offload is not enabled, the error handling path
causes a kernel crash due to kernel NULL pointer deference.
Fix this by adding check for NULL before attempt to access 'plat->est'
on the mutex_lock() call.
The following kernel panic is observed without this patch:
RIP: 0010:mutex_lock+0x10/0x20
Call Trace:
tc_setup_taprio+0x482/0x560 [stmmac]
kmem_cache_alloc_trace+0x13f/0x490
taprio_disable_offload.isra.0+0x9d/0x180 [sch_taprio]
taprio_destroy+0x6c/0x100 [sch_taprio]
qdisc_create+0x2e5/0x4f0
tc_modify_qdisc+0x126/0x740
rtnetlink_rcv_msg+0x12b/0x380
_raw_spin_lock_irqsave+0x19/0x40
_raw_spin_unlock_irqrestore+0x18/0x30
create_object+0x212/0x340
rtnl_calcit.isra.0+0x110/0x110
netlink_rcv_skb+0x50/0x100
netlink_unicast+0x191/0x230
netlink_sendmsg+0x243/0x470
sock_sendmsg+0x5e/0x60
____sys_sendmsg+0x20b/0x280
copy_msghdr_from_user+0x5c/0x90
__mod_memcg_state+0x87/0xf0
___sys_sendmsg+0x7c/0xc0
lru_cache_add+0x7f/0xa0
_raw_spin_unlock+0x16/0x30
wp_page_copy+0x449/0x890
handle_mm_fault+0x921/0xfc0
__sys_sendmsg+0x59/0xa0
do_syscall_64+0x33/0x40
entry_SYSCALL_64_after_hwframe+0x44/0xa9
---[ end trace b1f19b24368a96aa ]---
Fixes: b60189e0392f ("net: stmmac: Integrate EST with TAPRIO scheduler API")
Cc: <stable@xxxxxxxxxxxxxxx> # 5.10.x
Signed-off-by: Wong Vee Khee <vee.khee.wong@xxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c
index 4f3b6437b114..8160087ee92f 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c
@@ -884,11 +884,13 @@ static int tc_setup_taprio(struct stmmac_priv *priv,
return 0;
disable:
- mutex_lock(&priv->plat->est->lock);
- priv->plat->est->enable = false;
- stmmac_est_configure(priv, priv->ioaddr, priv->plat->est,
- priv->plat->clk_ptp_rate);
- mutex_unlock(&priv->plat->est->lock);
+ if (priv->plat->est) {
+ mutex_lock(&priv->plat->est->lock);
+ priv->plat->est->enable = false;
+ stmmac_est_configure(priv, priv->ioaddr, priv->plat->est,
+ priv->plat->clk_ptp_rate);
+ mutex_unlock(&priv->plat->est->lock);
+ }
priv->plat->fpe_cfg->enable = false;
stmmac_fpe_configure(priv, priv->ioaddr,
