Re: [PATCH] ARM: socfpga: Fix crash with CONFIG_FORTIRY_SOURCE
From: Kees Cook <hidden>
Date: 2021-11-17 22:01:57
Also in:
linux-hardening, lkml
Subsystem:
arm port, arm/socfpga architecture, the rest · Maintainers:
Russell King, Dinh Nguyen, Linus Torvalds
On Wed, Nov 17, 2021 at 08:32:44PM +0100, Takashi Iwai wrote:
When CONFIG_FORTIFY_SOURCE is set, memcpy() checks the potential buffer overflow and panics. The code in sofcpga bootstrapping contains the memcpy() calls are mistakenly translated as the shorter size, hence it triggers a panic as if it were overflowing. This patch adds the __NO_FORTIFY define for avoiding the false-positive crash. Buglink: https://bugzilla.suse.com/show_bug.cgi?id=1192473 Signed-off-by: Takashi Iwai <redacted> --- I took an easier path for now, as the attempt with a foced cast failed. If there is a better way to handle, let me know, I'd happily resubmit. Thanks!
The way these have been fixed in the past is to declare these as char arrays (see include/asm-generic/sections.h). I'd prefer something like this (totally untested):
diff --git a/arch/arm/mach-socfpga/core.h b/arch/arm/mach-socfpga/core.h
index fc2608b18a0d..18f01190dcfd 100644
--- a/arch/arm/mach-socfpga/core.h
+++ b/arch/arm/mach-socfpga/core.h@@ -33,7 +33,7 @@ extern void __iomem *sdr_ctl_base_addr; u32 socfpga_sdram_self_refresh(u32 sdr_base); extern unsigned int socfpga_sdram_self_refresh_sz; -extern char secondary_trampoline, secondary_trampoline_end; +extern char secondary_trampoline[], secondary_trampoline_end[]; extern unsigned long socfpga_cpu1start_addr;
diff --git a/arch/arm/mach-socfpga/platsmp.c b/arch/arm/mach-socfpga/platsmp.c
index fbb80b883e5d..201191cf68f3 100644
--- a/arch/arm/mach-socfpga/platsmp.c
+++ b/arch/arm/mach-socfpga/platsmp.c@@ -20,14 +20,14 @@ static int socfpga_boot_secondary(unsigned int cpu, struct task_struct *idle) { - int trampoline_size = &secondary_trampoline_end - &secondary_trampoline; + int trampoline_size = secondary_trampoline_end - secondary_trampoline; if (socfpga_cpu1start_addr) { /* This will put CPU #1 into reset. */ writel(RSTMGR_MPUMODRST_CPU1, rst_manager_base_addr + SOCFPGA_RSTMGR_MODMPURST); - memcpy(phys_to_virt(0), &secondary_trampoline, trampoline_size); + memcpy(phys_to_virt(0), secondary_trampoline, trampoline_size); writel(__pa_symbol(secondary_startup), sys_manager_base_addr + (socfpga_cpu1start_addr & 0x000000ff));
@@ -45,12 +45,12 @@ static int socfpga_boot_secondary(unsigned int cpu, struct task_struct *idle) static int socfpga_a10_boot_secondary(unsigned int cpu, struct task_struct *idle) { - int trampoline_size = &secondary_trampoline_end - &secondary_trampoline; + int trampoline_size = secondary_trampoline_end - secondary_trampoline; if (socfpga_cpu1start_addr) { writel(RSTMGR_MPUMODRST_CPU1, rst_manager_base_addr + SOCFPGA_A10_RSTMGR_MODMPURST); - memcpy(phys_to_virt(0), &secondary_trampoline, trampoline_size); + memcpy(phys_to_virt(0), secondary_trampoline, trampoline_size); writel(__pa_symbol(secondary_startup), sys_manager_base_addr + (socfpga_cpu1start_addr & 0x00000fff));
quoted hunk ↗ jump to hunk
arch/arm/mach-socfpga/platsmp.c | 3 +++ 1 file changed, 3 insertions(+)diff --git a/arch/arm/mach-socfpga/platsmp.c b/arch/arm/mach-socfpga/platsmp.c index fbb80b883e5d..d46b1af96a8a 100644 --- a/arch/arm/mach-socfpga/platsmp.c +++ b/arch/arm/mach-socfpga/platsmp.c@@ -5,6 +5,9 @@ * Based on platsmp.c, Copyright (C) 2002 ARM Ltd. * Copyright (C) 2012 Altera Corporation */ + +#define __NO_FORTIFY /* need to avoid the crash with memcpy() calls */ + #include <linux/delay.h> #include <linux/init.h> #include <linux/smp.h>-- 2.26.2
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