[PATCH v2] ARM: socfpga: Fix crash with CONFIG_FORTIRY_SOURCE

From: Takashi Iwai
Date: Thu Nov 18 2021 - 09:25:25 EST


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 changes the secondary_trampoline and *_end definitions
to arrays for avoiding the false-positive crash above.

Suggested-by: Kees Cook <keescook@xxxxxxxxxxxx>
Buglink: https://bugzilla.suse.com/show_bug.cgi?id=1192473
Link: https://lore.kernel.org/r/20211117193244.31162-1-tiwai@xxxxxxx
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
---

v1->v2: Use arrays for trampoline area instead of hackish workaround
with __NO_FORTIFY

arch/arm/mach-socfpga/core.h | 2 +-
arch/arm/mach-socfpga/platsmp.c | 8 ++++----
2 files changed, 5 insertions(+), 5 deletions(-)

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));
--
2.26.2