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author | Albert van der Linde <alinde@google.com> | 2020-09-17 11:56:47 +1000 |
---|---|---|
committer | Stephen Rothwell <sfr@canb.auug.org.au> | 2020-09-17 11:56:47 +1000 |
commit | c7b47e308648e61ce0f951438123fb716aab1e09 (patch) | |
tree | e401d203357fc53c5bdc96e5b6a1ba1e4fa24936 | |
parent | 1b740251ae9b6c96e3b717d2c0bf6a2a57c2df9f (diff) | |
download | linux-c7b47e308648e61ce0f951438123fb716aab1e09.tar.gz linux-c7b47e308648e61ce0f951438123fb716aab1e09.tar.xz |
x86: add failure injection to get/put/clear_user
To test fault-tolerance of user memory acceses in x86, add support for
fault injection.
Make both put_user() and get_user() fail with -EFAULT, and clear_user()
fail by not clearing any bytes.
Link: http://lkml.kernel.org/r/20200831171733.955393-4-alinde@google.com
Signed-off-by: Albert van der Linde <alinde@google.com>
Reviewed-by: Akinobu Mita <akinobu.mita@gmail.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Marco Elver <elver@google.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
-rw-r--r-- | arch/x86/include/asm/uaccess.h | 68 | ||||
-rw-r--r-- | arch/x86/lib/usercopy_64.c | 3 |
2 files changed, 42 insertions, 29 deletions
diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h index ecefaffd15d4..004eeee2199a 100644 --- a/arch/x86/include/asm/uaccess.h +++ b/arch/x86/include/asm/uaccess.h @@ -5,6 +5,7 @@ * User space memory access functions */ #include <linux/compiler.h> +#include <linux/fault-inject-usercopy.h> #include <linux/kasan-checks.h> #include <linux/string.h> #include <asm/asm.h> @@ -175,11 +176,16 @@ extern int __get_user_bad(void); register __inttype(*(ptr)) __val_gu asm("%"_ASM_DX); \ __chk_user_ptr(ptr); \ might_fault(); \ - asm volatile("call __get_user_%P4" \ - : "=a" (__ret_gu), "=r" (__val_gu), \ + if (should_fail_usercopy()) { \ + (x) = 0; \ + __ret_gu = -EFAULT; \ + } else { \ + asm volatile("call __get_user_%P4" \ + : "=a" (__ret_gu), "=r" (__val_gu), \ ASM_CALL_CONSTRAINT \ - : "0" (ptr), "i" (sizeof(*(ptr)))); \ - (x) = (__force __typeof__(*(ptr))) __val_gu; \ + : "0" (ptr), "i" (sizeof(*(ptr)))); \ + (x) = (__force __typeof__(*(ptr))) __val_gu; \ + } \ __builtin_expect(__ret_gu, 0); \ }) @@ -236,31 +242,35 @@ extern void __put_user_8(void); * * Return: zero on success, or -EFAULT on error. */ -#define put_user(x, ptr) \ -({ \ - int __ret_pu; \ - __typeof__(*(ptr)) __pu_val; \ - __chk_user_ptr(ptr); \ - might_fault(); \ - __pu_val = x; \ - switch (sizeof(*(ptr))) { \ - case 1: \ - __put_user_x(1, __pu_val, ptr, __ret_pu); \ - break; \ - case 2: \ - __put_user_x(2, __pu_val, ptr, __ret_pu); \ - break; \ - case 4: \ - __put_user_x(4, __pu_val, ptr, __ret_pu); \ - break; \ - case 8: \ - __put_user_x8(__pu_val, ptr, __ret_pu); \ - break; \ - default: \ - __put_user_x(X, __pu_val, ptr, __ret_pu); \ - break; \ - } \ - __builtin_expect(__ret_pu, 0); \ +#define put_user(x, ptr) \ +({ \ + int __ret_pu; \ + __typeof__(*(ptr)) __pu_val; \ + __chk_user_ptr(ptr); \ + might_fault(); \ + __pu_val = x; \ + if (should_fail_usercopy()) { \ + __ret_pu = -EFAULT; \ + } else { \ + switch (sizeof(*(ptr))) { \ + case 1: \ + __put_user_x(1, __pu_val, ptr, __ret_pu); \ + break; \ + case 2: \ + __put_user_x(2, __pu_val, ptr, __ret_pu); \ + break; \ + case 4: \ + __put_user_x(4, __pu_val, ptr, __ret_pu); \ + break; \ + case 8: \ + __put_user_x8(__pu_val, ptr, __ret_pu); \ + break; \ + default: \ + __put_user_x(X, __pu_val, ptr, __ret_pu); \ + break; \ + } \ + } \ + __builtin_expect(__ret_pu, 0); \ }) #define __put_user_size(x, ptr, size, label) \ diff --git a/arch/x86/lib/usercopy_64.c b/arch/x86/lib/usercopy_64.c index 1847e993ac63..9c2d53a96e5e 100644 --- a/arch/x86/lib/usercopy_64.c +++ b/arch/x86/lib/usercopy_64.c @@ -7,6 +7,7 @@ * Copyright 2002 Andi Kleen <ak@suse.de> */ #include <linux/export.h> +#include <linux/fault-inject-usercopy.h> #include <linux/uaccess.h> #include <linux/highmem.h> @@ -50,6 +51,8 @@ EXPORT_SYMBOL(__clear_user); unsigned long clear_user(void __user *to, unsigned long n) { + if (should_fail_usercopy()) + return n; if (access_ok(to, n)) return __clear_user(to, n); return n; |