diff options
| author | Andrew Donnellan <ajd@linux.ibm.com> | 2020-11-20 11:07:02 +1100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-11-22 09:56:58 +0100 |
| commit | 452e2a83ea2355ad817c9933aa5b56d2d8423aa5 (patch) | |
| tree | 3635d4d6dd77e8d28a1606e5eadfecfafbe86f4e /arch/powerpc/kernel | |
| parent | 79e649b1c1c9f6a007d0877fad10f638a88c65c9 (diff) | |
powerpc: Fix __clear_user() with KUAP enabled
commit 61e3acd8c693a14fc69b824cb5b08d02cb90a6e7 upstream.
The KUAP implementation adds calls in clear_user() to enable and
disable access to userspace memory. However, it doesn't add these to
__clear_user(), which is used in the ptrace regset code.
As there's only one direct user of __clear_user() (the regset code),
and the time taken to set the AMR for KUAP purposes is going to
dominate the cost of a quick access_ok(), there's not much point
having a separate path.
Rename __clear_user() to __arch_clear_user(), and make __clear_user()
just call clear_user().
Reported-by: syzbot+f25ecf4b2982d8c7a640@syzkaller-ppc64.appspotmail.com
Reported-by: Daniel Axtens <dja@axtens.net>
Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
Fixes: de78a9c42a79 ("powerpc: Add a framework for Kernel Userspace Access Protection")
Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com>
[mpe: Use __arch_clear_user() for the asm version like arm64 & nds32]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191209132221.15328-1-ajd@linux.ibm.com
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/powerpc/kernel')
| -rw-r--r-- | arch/powerpc/kernel/ppc_ksyms.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/ppc_ksyms.c b/arch/powerpc/kernel/ppc_ksyms.c index 202963ee013a..b92debacb821 100644 --- a/arch/powerpc/kernel/ppc_ksyms.c +++ b/arch/powerpc/kernel/ppc_ksyms.c @@ -5,6 +5,7 @@ #include <asm/switch_to.h> #include <asm/cacheflush.h> #include <asm/epapr_hcalls.h> +#include <asm/uaccess.h> EXPORT_SYMBOL(flush_dcache_range); EXPORT_SYMBOL(flush_icache_range); @@ -43,3 +44,5 @@ EXPORT_SYMBOL(epapr_hypercall_start); #endif EXPORT_SYMBOL(current_stack_pointer); + +EXPORT_SYMBOL(__arch_clear_user); |