[PATCH net-next] net: stmmac: Fix kernel panic due to NULL pointer dereference of fpe_cfg
From: mohammad . athari . ismail
Date: Fri Mar 26 2021 - 05:12:05 EST
From: Mohammad Athari Bin Ismail <mohammad.athari.ismail@xxxxxxxxx>
In this patch, "net: stmmac: support FPE link partner hand-shaking
procedure", priv->plat->fpe_cfg wouldn`t be "devm_kzalloc"ed if
dma_cap->frpsel is 0 (Flexible Rx Parser is not supported in SoC) in
tc_init(). So, fpe_cfg will be remain as NULL and accessing it will cause
kernel panic.
To fix this, move the "devm_kzalloc"ing of priv->plat->fpe_cfg before
dma_cap->frpsel checking in tc_init(). Additionally, checking of
priv->dma_cap.fpesel is added before calling stmmac_fpe_link_state_handle()
as only FPE supported SoC is allowed to call the function.
Below is the kernel panic dump reported by Marek Szyprowski
<m.szyprowski@xxxxxxxxxxx>:
meson8b-dwmac ff3f0000.ethernet eth0: PHY [0.0:00] driver [RTL8211F Gigabit Ethernet] (irq=35)
meson8b-dwmac ff3f0000.ethernet eth0: No Safety Features support found
meson8b-dwmac ff3f0000.ethernet eth0: PTP not supported by HW
meson8b-dwmac ff3f0000.ethernet eth0: configuring for phy/rgmii link mode
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000001
Mem abort info:
...
user pgtable: 4k pages, 48-bit VAs, pgdp=00000000044eb000
[0000000000000001] pgd=0000000000000000, p4d=0000000000000000
Internal error: Oops: 96000004 [#1] PREEMPT SMP
Modules linked in: dw_hdmi_i2s_audio dw_hdmi_cec meson_gxl realtek meson_gxbb_wdt snd_soc_meson_axg_sound_card dwmac_generic axg_audio meson_dw_hdmi crct10dif_ce snd_soc_meson_card_utils snd_soc_meson_axg_tdmout panfrost rc_odroid gpu_sched reset_meson_audio_arb meson_ir snd_soc_meson_g12a_tohdmitx snd_soc_meson_axg_frddr sclk_div clk_phase snd_soc_meson_codec_glue dwmac_meson8b snd_soc_meson_axg_fifo stmmac_platform meson_rng meson_drm stmmac rtc_meson_vrtc rng_core meson_canvas pwm_meson dw_hdmi mdio_mux_meson_g12a pcs_xpcs snd_soc_meson_axg_tdm_interface snd_soc_meson_axg_tdm_formatter nvmem_meson_efuse display_connector
CPU: 1 PID: 7 Comm: kworker/u8:0 Not tainted 5.12.0-rc4-next-20210325+
Hardware name: Hardkernel ODROID-C4 (DT)
Workqueue: events_power_efficient phylink_resolve
pstate: 20400009 (nzCv daif +PAN -UAO -TCO BTYPE=--)
pc : stmmac_mac_link_up+0x14c/0x348 [stmmac]
lr : stmmac_mac_link_up+0x284/0x348 [stmmac] ...
Call trace:
stmmac_mac_link_up+0x14c/0x348 [stmmac]
phylink_resolve+0x104/0x420
process_one_work+0x2a8/0x718
worker_thread+0x48/0x460
kthread+0x134/0x160
ret_from_fork+0x10/0x18
Code: b971ba60 350007c0 f958c260 f9402000 (39400401)
---[ end trace 0c9deb6c510228aa ]---
Fixes: 5a5586112b92 ("net: stmmac: support FPE link partner hand-shaking
procedure")
Reported-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
Signed-off-by: Mohammad Athari Bin Ismail <mohammad.athari.ismail@xxxxxxxxx>
---
.../net/ethernet/stmicro/stmmac/stmmac_main.c | 6 ++++--
.../net/ethernet/stmicro/stmmac/stmmac_tc.c | 20 +++++++++----------
2 files changed, 14 insertions(+), 12 deletions(-)
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 170296820af0..27faf5e49360 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -997,7 +997,8 @@ static void stmmac_mac_link_down(struct phylink_config *config,
stmmac_eee_init(priv);
stmmac_set_eee_pls(priv, priv->hw, false);
- stmmac_fpe_link_state_handle(priv, false);
+ if (priv->dma_cap.fpesel)
+ stmmac_fpe_link_state_handle(priv, false);
}
static void stmmac_mac_link_up(struct phylink_config *config,
@@ -1097,7 +1098,8 @@ static void stmmac_mac_link_up(struct phylink_config *config,
stmmac_set_eee_pls(priv, priv->hw, true);
}
- stmmac_fpe_link_state_handle(priv, true);
+ if (priv->dma_cap.fpesel)
+ stmmac_fpe_link_state_handle(priv, true);
}
static const struct phylink_mac_ops stmmac_phylink_mac_ops = {
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c
index 1d84ee359808..4e70efc45458 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c
@@ -254,6 +254,16 @@ static int tc_init(struct stmmac_priv *priv)
priv->flow_entries_max);
}
+ if (!priv->plat->fpe_cfg) {
+ priv->plat->fpe_cfg = devm_kzalloc(priv->device,
+ sizeof(*priv->plat->fpe_cfg),
+ GFP_KERNEL);
+ if (!priv->plat->fpe_cfg)
+ return -ENOMEM;
+ } else {
+ memset(priv->plat->fpe_cfg, 0, sizeof(*priv->plat->fpe_cfg));
+ }
+
/* Fail silently as we can still use remaining features, e.g. CBS */
if (!dma_cap->frpsel)
return 0;
@@ -298,16 +308,6 @@ static int tc_init(struct stmmac_priv *priv)
dev_info(priv->device, "Enabling HW TC (entries=%d, max_off=%d)\n",
priv->tc_entries_max, priv->tc_off_max);
- if (!priv->plat->fpe_cfg) {
- priv->plat->fpe_cfg = devm_kzalloc(priv->device,
- sizeof(*priv->plat->fpe_cfg),
- GFP_KERNEL);
- if (!priv->plat->fpe_cfg)
- return -ENOMEM;
- } else {
- memset(priv->plat->fpe_cfg, 0, sizeof(*priv->plat->fpe_cfg));
- }
-
return 0;
}
--
2.17.1