[PATCH v1] net: ethernet: fix NULL pointer dereference at fec_ptp_save_state()
From: dillon . minfei
Date: Tue Oct 08 2024 - 05:18:32 EST
From: Dillon Min <dillon.minfei@xxxxxxxxx>
fec_ptp_init() called at probe stage when 'bufdesc_ex' is true.
so, need add 'bufdesc_ex' check before call fec_ptp_save_state(),
else 'tmreg_lock' will not be init by spin_lock_init().
run into kernel panic:
[ 5.735628] Hardware name: Freescale MXS (Device Tree)
[ 5.740816] Call trace:
[ 5.740853] unwind_backtrace from show_stack+0x10/0x14
[ 5.748788] show_stack from dump_stack_lvl+0x44/0x60
[ 5.753970] dump_stack_lvl from register_lock_class+0x80c/0x888
[ 5.760098] register_lock_class from __lock_acquire+0x94/0x2b84
[ 5.766213] __lock_acquire from lock_acquire+0xe0/0x2e0
[ 5.771630] lock_acquire from _raw_spin_lock_irqsave+0x5c/0x78
[ 5.777666] _raw_spin_lock_irqsave from fec_ptp_save_state+0x14/0x68
[ 5.784226] fec_ptp_save_state from fec_restart+0x2c/0x778
[ 5.789910] fec_restart from fec_probe+0xc68/0x15e0
[ 5.794977] fec_probe from platform_probe+0x58/0xb0
[ 5.800059] platform_probe from really_probe+0xc4/0x2cc
[ 5.805473] really_probe from __driver_probe_device+0x84/0x19c
[ 5.811482] __driver_probe_device from driver_probe_device+0x30/0x110
[ 5.818103] driver_probe_device from __driver_attach+0x94/0x18c
[ 5.824200] __driver_attach from bus_for_each_dev+0x70/0xc4
[ 5.829979] bus_for_each_dev from bus_add_driver+0xc4/0x1ec
[ 5.835762] bus_add_driver from driver_register+0x7c/0x114
[ 5.841444] driver_register from do_one_initcall+0x4c/0x224
[ 5.847205] do_one_initcall from kernel_init_freeable+0x198/0x224
[ 5.853502] kernel_init_freeable from kernel_init+0x10/0x108
[ 5.859370] kernel_init from ret_from_fork+0x14/0x38
[ 5.864524] Exception stack(0xc4819fb0 to 0xc4819ff8)
[ 5.869650] 9fa0: 00000000 00000000 00000000 00000000
[ 5.877901] 9fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[ 5.886148] 9fe0: 00000000 00000000 00000000 00000000 00000013 00000000
[ 5.892838] 8<--- cut here ---
[ 5.895948] Unable to handle kernel NULL pointer dereference at virtual address 00000000 when read
Fixes: a1477dc87dc4 ("net: fec: Restart PPS after link state change")
Signed-off-by: Dillon Min <dillon.minfei@xxxxxxxxx>
---
drivers/net/ethernet/freescale/fec_main.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index 60fb54231ead..1b55047c0237 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -1077,7 +1077,8 @@ fec_restart(struct net_device *ndev)
u32 rcntl = OPT_FRAME_SIZE | 0x04;
u32 ecntl = FEC_ECR_ETHEREN;
- fec_ptp_save_state(fep);
+ if (fep->bufdesc_ex)
+ fec_ptp_save_state(fep);
/* Whack a reset. We should wait for this.
* For i.MX6SX SOC, enet use AXI bus, we use disable MAC
@@ -1340,7 +1341,8 @@ fec_stop(struct net_device *ndev)
netdev_err(ndev, "Graceful transmit stop did not complete!\n");
}
- fec_ptp_save_state(fep);
+ if (fep->bufdesc_ex)
+ fec_ptp_save_state(fep);
/* Whack a reset. We should wait for this.
* For i.MX6SX SOC, enet use AXI bus, we use disable MAC
--
2.25.1