From 63c173ff7aa3b58b1f5cd4227f53455a78cea627 Mon Sep 17 00:00:00 2001 From: Mohammad Athari Bin Ismail Date: Fri, 26 Mar 2021 17:10:46 +0800 Subject: [PATCH] net: stmmac: Fix kernel panic due to NULL pointer dereference of fpe_cfg 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 : 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 Signed-off-by: Mohammad Athari Bin Ismail Tested-by: Marek Szyprowski Signed-off-by: David S. Miller --- .../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 f4fa5402cd64..3a4f0c2d42a3 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c @@ -1002,7 +1002,8 @@ 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, @@ -1102,7 +1103,8 @@ 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; }