From: Nathan Chancellor <nathan@kernel.org> stable inclusion from stable-v4.19.239 commit c64e2ed5cc376e137e572babfd2edc38b2cfb61b category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IBP62H CVE: CVE-2021-47631 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- commit 83a1cde5c74bfb44b49cb2a940d044bb2380f4ea upstream. With newer versions of GCC, there is a panic in da850_evm_config_emac() when booting multi_v5_defconfig in QEMU under the palmetto-bmc machine: Unable to handle kernel NULL pointer dereference at virtual address 00000020 pgd = (ptrval) [00000020] *pgd=00000000 Internal error: Oops: 5 [#1] PREEMPT ARM Modules linked in: CPU: 0 PID: 1 Comm: swapper Not tainted 5.15.0 #1 Hardware name: Generic DT based system PC is at da850_evm_config_emac+0x1c/0x120 LR is at do_one_initcall+0x50/0x1e0 The emac_pdata pointer in soc_info is NULL because davinci_soc_info only gets populated on davinci machines but da850_evm_config_emac() is called on all machines via device_initcall(). Move the rmii_en assignment below the machine check so that it is only dereferenced when running on a supported SoC. Fixes: bae105879f2f ("davinci: DA850/OMAP-L138 EVM: implement autodetect of RMII PHY") Signed-off-by: Nathan Chancellor <nathan@kernel.org> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Bartosz Golaszewski <brgl@bgdev.pl> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/YcS4xVWs6bQlQSPC@archlinux-ax161/ Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Yuntao Liu <liuyuntao12@huawei.com> --- arch/arm/mach-davinci/board-da850-evm.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/arm/mach-davinci/board-da850-evm.c b/arch/arm/mach-davinci/board-da850-evm.c index 774a3e535ad0..2afc2ff6f55a 100644 --- a/arch/arm/mach-davinci/board-da850-evm.c +++ b/arch/arm/mach-davinci/board-da850-evm.c @@ -1045,11 +1045,13 @@ static int __init da850_evm_config_emac(void) int ret; u32 val; struct davinci_soc_info *soc_info = &davinci_soc_info; - u8 rmii_en = soc_info->emac_pdata->rmii_en; + u8 rmii_en; if (!machine_is_davinci_da850_evm()) return 0; + rmii_en = soc_info->emac_pdata->rmii_en; + cfg_chip3_base = DA8XX_SYSCFG0_VIRT(DA8XX_CFGCHIP3_REG); val = __raw_readl(cfg_chip3_base); -- 2.34.1