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authorWong Vee Khee <vee.khee.wong@linux.intel.com>2021-08-20 21:26:22 +0800
committerDavid S. Miller <davem@davemloft.net>2021-08-23 11:49:34 +0100
commit82a44ae113b7b35850f4542f0443fcab221e376a (patch)
treeb62d79a80d0d14559812581f65651256baab2458
parent46002bf3007ce0387be73d0c9640ee7cd2de4788 (diff)
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@vger.kernel.org> # 5.10.x Signed-off-by: Wong Vee Khee <vee.khee.wong@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c12
1 files changed, 7 insertions, 5 deletions
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,