2021-11-18 14:25:25

by Takashi Iwai

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

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 <[email protected]>
Buglink: https://bugzilla.suse.com/show_bug.cgi?id=1192473
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Takashi Iwai <[email protected]>
---

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

2021-11-18 17:20:54

by Kees Cook

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

On Thu, Nov 18, 2021 at 03:25:08PM +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 changes the secondary_trampoline and *_end definitions
> to arrays for avoiding the false-positive crash above.
>
> Suggested-by: Kees Cook <[email protected]>
> Buglink: https://bugzilla.suse.com/show_bug.cgi?id=1192473
> Link: https://lore.kernel.org/r/[email protected]
> Signed-off-by: Takashi Iwai <[email protected]>

Reviewed-by: Kees Cook <[email protected]>

Thanks!

--
Kees Cook

2021-11-18 22:08:31

by Dinh Nguyen

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

Hi Iwai,

Should this have the following tag:

Fixes: 9c4566a117a6 ("ARM: socfpga: Enable SMP for socfpga")

As well?

On 11/18/21 8:25 AM, 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 changes the secondary_trampoline and *_end definitions
> to arrays for avoiding the false-positive crash above.
>
> Suggested-by: Kees Cook <[email protected]>
> Buglink: https://bugzilla.suse.com/show_bug.cgi?id=1192473
> Link: https://lore.kernel.org/r/[email protected]
> Signed-off-by: Takashi Iwai <[email protected]>
> ---
>
> 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));
>

2021-11-19 13:37:28

by Takashi Iwai

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

On Thu, 18 Nov 2021 23:08:27 +0100,
Dinh Nguyen wrote:
>
> Hi Iwai,
>
> Should this have the following tag:
>
> Fixes: 9c4566a117a6 ("ARM: socfpga: Enable SMP for socfpga")
>
> As well?

Yes, that'd be helpful, too.


thanks,

Takashi

>
> On 11/18/21 8:25 AM, 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 changes the secondary_trampoline and *_end definitions
> > to arrays for avoiding the false-positive crash above.
> >
> > Suggested-by: Kees Cook <[email protected]>
> > Buglink: https://bugzilla.suse.com/show_bug.cgi?id=1192473
> > Link: https://lore.kernel.org/r/[email protected]
> > Signed-off-by: Takashi Iwai <[email protected]>
> > ---
> >
> > 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));
> >
>