| Message ID | 20220909105913.752049-3-gwan-gyeong.mun@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Fixes integer overflow or integer truncation issues in page lookups, ttm place configuration and scatterlist creation | expand |
On Fri, Sep 09, 2022 at 07:59:06PM +0900, Gwan-gyeong Mun wrote: > It moves overflows_type utility macro into overflow header from i915_utils > header. The overflows_type can be used to catch the truncaion (overflow) > between different data types. And it adds check_assign() macro which > performs an assigning source value into destination pointer along with an > overflow check. overflow_type macro has been improved to handle the > different data types between source and destination by check_add_overflow > macro. It also adds check_assign_user_ptr macro which performs an assigning > source value into destination pointer type variable along with an overflow > check. If an explicit overflow check is required while assigning, > check_assign_user_ptr() can be used to assign integers into pointers along > with an overflow check. > > v3: Add is_type_unsigned() macro (Mauro) > Modify overflows_type() macro to consider signed data types (Mauro) > Fix the problem that safe_conversion() macro always returns true > v4: Fix kernel-doc markups > v6: Move macro addition location so that it can be used by other than drm > subsystem (Jani, Mauro, Andi) > Change is_type_unsigned to is_unsigned_type to have the same name form > as is_signed_type macro > v8: Add check_assign() and remove safe_conversion() (Kees) > Fix overflows_type() to use gcc's built-in overflow function (Andrzej) > Add overflows_ptr() to allow overflow checking when assigning a value > into a pointer variable (G.G.) > v9: Fix overflows_type() to use __builtin_add_overflow() instead of > __builtin_add_overflow_p() (Andrzej) > Fix overflows_ptr() to use overflows_type() with the unsigned long type > (Andrzej) > v10: Remove a redundant type checking for a pointer. (Andrzej) > Use updated check_add_overflow macro instead of __builtin_add_overflow > (G.G) > Add check_assign_user_ptr() macro and drop overflows_ptr() macro(Kees) > > Signed-off-by: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com> Acked-by: Kees Cook <keescook@chromium.org>
Hi Gwan-gyeong,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on drm-tip/drm-tip]
[also build test WARNING on linus/master v6.0-rc5]
[cannot apply to drm-intel/for-linux-next kees/for-next/hardening next-20220916]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Gwan-gyeong-Mun/Fixes-integer-overflow-or-integer-truncation-issues-in-page-lookups-ttm-place-configuration-and-scatterlist-creation/20220909-190301
base: git://anongit.freedesktop.org/drm/drm-tip drm-tip
config: i386-randconfig-s002 (https://download.01.org/0day-ci/archive/20220918/202209180742.kE2Xbxqz-lkp@intel.com/config)
compiler: gcc-11 (Debian 11.3.0-5) 11.3.0
reproduce:
# apt-get install sparse
# sparse version: v0.6.4-39-gce1a6720-dirty
# https://github.com/intel-lab-lkp/linux/commit/8d39d691758034d1082773e43b9cb4738b1f4387
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Gwan-gyeong-Mun/Fixes-integer-overflow-or-integer-truncation-issues-in-page-lookups-ttm-place-configuration-and-scatterlist-creation/20220909-190301
git checkout 8d39d691758034d1082773e43b9cb4738b1f4387
# save the config file
mkdir build_dir && cp config build_dir/.config
make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=i386 SHELL=/bin/bash drivers/gpu/drm/i915/
If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp@intel.com>
sparse warnings: (new ones prefixed by >>)
>> drivers/gpu/drm/i915/i915_user_extensions.c:56:21: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected struct i915_user_extension [noderef] __user *ext @@ got void *[noderef] __user @@
drivers/gpu/drm/i915/i915_user_extensions.c:56:21: sparse: expected struct i915_user_extension [noderef] __user *ext
drivers/gpu/drm/i915/i915_user_extensions.c:56:21: sparse: got void *[noderef] __user
vim +56 drivers/gpu/drm/i915/i915_user_extensions.c
15
16 int i915_user_extensions(struct i915_user_extension __user *ext,
17 const i915_user_extension_fn *tbl,
18 unsigned int count,
19 void *data)
20 {
21 unsigned int stackdepth = 512;
22
23 while (ext) {
24 int i, err;
25 u32 name;
26 u64 next;
27
28 if (!stackdepth--) /* recursion vs useful flexibility */
29 return -E2BIG;
30
31 err = check_user_mbz(&ext->flags);
32 if (err)
33 return err;
34
35 for (i = 0; i < ARRAY_SIZE(ext->rsvd); i++) {
36 err = check_user_mbz(&ext->rsvd[i]);
37 if (err)
38 return err;
39 }
40
41 if (get_user(name, &ext->name))
42 return -EFAULT;
43
44 err = -EINVAL;
45 if (name < count) {
46 name = array_index_nospec(name, count);
47 if (tbl[name])
48 err = tbl[name](ext, data);
49 }
50 if (err)
51 return err;
52
53 if (get_user(next, &ext->next_extension))
54 return -EFAULT;
55
> 56 if (check_assign_user_ptr(next, ext))
diff --git a/drivers/gpu/drm/i915/i915_user_extensions.c b/drivers/gpu/drm/i915/i915_user_extensions.c index c822d0aafd2d..80ec8390b0d8 100644 --- a/drivers/gpu/drm/i915/i915_user_extensions.c +++ b/drivers/gpu/drm/i915/i915_user_extensions.c @@ -50,11 +50,11 @@ int i915_user_extensions(struct i915_user_extension __user *ext, if (err) return err; - if (get_user(next, &ext->next_extension) || - overflows_type(next, ext)) + if (get_user(next, &ext->next_extension)) return -EFAULT; - ext = u64_to_user_ptr(next); + if (check_assign_user_ptr(next, ext)) + return -EFAULT; } return 0; diff --git a/drivers/gpu/drm/i915/i915_utils.h b/drivers/gpu/drm/i915/i915_utils.h index 6c14d13364bf..efd3d69b78f7 100644 --- a/drivers/gpu/drm/i915/i915_utils.h +++ b/drivers/gpu/drm/i915/i915_utils.h @@ -32,6 +32,7 @@ #include <linux/types.h> #include <linux/workqueue.h> #include <linux/sched/clock.h> +#include <linux/overflow.h> #ifdef CONFIG_X86 #include <asm/hypervisor.h> @@ -111,10 +112,6 @@ bool i915_error_injected(void); #define range_overflows_end_t(type, start, size, max) \ range_overflows_end((type)(start), (type)(size), (type)(max)) -/* Note we don't consider signbits :| */ -#define overflows_type(x, T) \ - (sizeof(x) > sizeof(T) && (x) >> BITS_PER_TYPE(T)) - #define ptr_mask_bits(ptr, n) ({ \ unsigned long __v = (unsigned long)(ptr); \ (typeof(ptr))(__v & -BIT(n)); \ diff --git a/include/linux/overflow.h b/include/linux/overflow.h index 19dfdd74835e..9e8fc8f03e7a 100644 --- a/include/linux/overflow.h +++ b/include/linux/overflow.h @@ -5,6 +5,7 @@ #include <linux/compiler.h> #include <linux/limits.h> #include <linux/const.h> +#include <linux/types.h> /* * We need to compute the minimum and maximum values representable in a given @@ -127,6 +128,69 @@ static inline bool __must_check __must_check_overflow(bool overflow) (*_d >> _to_shift) != _a); \ })) +/** + * check_assign - perform an assigning source value into destination pointer + * along with an overflow check. + * + * @value: source value + * @ptr: Destination pointer address + * + * Returns: + * If the value would overflow the destination, it returns true. If not return + * false. When overflow does not occur, the assigning into destination from + * value succeeds. It follows the return policy as other check_*_overflow() + * functions return non-zero as a failure. + */ +#define check_assign(value, ptr) __must_check_overflow(({ \ + check_add_overflow(0, value, ptr); \ +})) + +/** + * check_assign_user_ptr - perform an assigning source value into destination + * pointer type variable along with an overflow check + * + * @value: source value; a source value is expected to have a value of a size + * that can be stored in a pointer-type variable. + * @ptr: destination pointer type variable + * + * u64_to_user_ptr can be used in the kernel to avoid warnings about integers + * and pointers of different sizes. But u64_to_user_ptr is not performing the + * checking of overflow. If you need an explicit overflow check while + * assigning, check_assign_user_ptr() can be used to assign integers into + * pointers along with an overflow check. If ptr is not a pointer type, + * a warning message outputs while compiling. + * + * Returns: + * If the value would overflow the destination, it returns true. If not return + * false. When overflow does not occur, the assigning into ptr from value + * succeeds. It follows the return policy as other check_*_overflow() functions + * return non-zero as a failure. + */ +#define check_assign_user_ptr(value, ptr) __must_check_overflow(({ \ + uintptr_t kptr; \ + check_assign(value, &kptr) ? 1 : (({ ptr = (void * __user)kptr; }), 0); \ +})) + +/** + * overflows_type - helper for checking the overflows between data types or + * values + * + * @x: source value or data type for overflow check + * @T: destination value or data type for overflow check + * + * It compares the values or data type between the first and second argument to + * check whether overflow can occur when assigning the first argument to the + * variable of the second argument. Source and Destination can be different data + * types. + * + * Returns: + * True if overflow can occur, false otherwise. + */ +#define overflows_type(x, T) __must_check_overflow(({ \ + typeof(T) v = 0; \ + check_add_overflow((x), v, &v); \ +})) + /** * size_mul() - Calculate size_t multiplication with saturation at SIZE_MAX *
It moves overflows_type utility macro into overflow header from i915_utils header. The overflows_type can be used to catch the truncaion (overflow) between different data types. And it adds check_assign() macro which performs an assigning source value into destination pointer along with an overflow check. overflow_type macro has been improved to handle the different data types between source and destination by check_add_overflow macro. It also adds check_assign_user_ptr macro which performs an assigning source value into destination pointer type variable along with an overflow check. If an explicit overflow check is required while assigning, check_assign_user_ptr() can be used to assign integers into pointers along with an overflow check. v3: Add is_type_unsigned() macro (Mauro) Modify overflows_type() macro to consider signed data types (Mauro) Fix the problem that safe_conversion() macro always returns true v4: Fix kernel-doc markups v6: Move macro addition location so that it can be used by other than drm subsystem (Jani, Mauro, Andi) Change is_type_unsigned to is_unsigned_type to have the same name form as is_signed_type macro v8: Add check_assign() and remove safe_conversion() (Kees) Fix overflows_type() to use gcc's built-in overflow function (Andrzej) Add overflows_ptr() to allow overflow checking when assigning a value into a pointer variable (G.G.) v9: Fix overflows_type() to use __builtin_add_overflow() instead of __builtin_add_overflow_p() (Andrzej) Fix overflows_ptr() to use overflows_type() with the unsigned long type (Andrzej) v10: Remove a redundant type checking for a pointer. (Andrzej) Use updated check_add_overflow macro instead of __builtin_add_overflow (G.G) Add check_assign_user_ptr() macro and drop overflows_ptr() macro(Kees) Signed-off-by: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com> Cc: Matthew Auld <matthew.auld@intel.com> Cc: Nirmoy Das <nirmoy.das@intel.com> Cc: Jani Nikula <jani.nikula@intel.com> Cc: Andi Shyti <andi.shyti@linux.intel.com> Cc: Andrzej Hajda <andrzej.hajda@intel.com> Cc: Mauro Carvalho Chehab <mauro.chehab@linux.intel.com> Cc: Kees Cook <keescook@chromium.org> Reviewed-by: Mauro Carvalho Chehab <mchehab@kernel.org> (v5) Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com> (v9) --- drivers/gpu/drm/i915/i915_user_extensions.c | 6 +- drivers/gpu/drm/i915/i915_utils.h | 5 +- include/linux/overflow.h | 64 +++++++++++++++++++++ 3 files changed, 68 insertions(+), 7 deletions(-)