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| author | Al Viro <viro@zeniv.linux.org.uk> | 2019-10-09 21:21:05 +0200 |
|---|---|---|
| committer | Max Filippov <jcmvbkbc@gmail.com> | 2019-10-14 20:39:50 +0200 |
| commit | 6595d144decec396bf2e2efee27e50634a4b627f (patch) | |
| tree | 91dfc29dc79a7a8d7e33df00b784e36ac5597b0b /arch/xtensa | |
| parent | Linux 5.4-rc3 (diff) | |
| download | linux-6595d144decec396bf2e2efee27e50634a4b627f.tar.xz linux-6595d144decec396bf2e2efee27e50634a4b627f.zip | |
xtensa: fix {get,put}_user() for 64bit values
First of all, on short copies __copy_{to,from}_user() return the amount
of bytes left uncopied, *not* -EFAULT. get_user() and put_user() are
expected to return -EFAULT on failure.
Another problem is get_user(v32, (__u64 __user *)p); that should
fetch 64bit value and the assign it to v32, truncating it in process.
Current code, OTOH, reads 8 bytes of data and stores them at the
address of v32, stomping on the 4 bytes that follow v32 itself.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Diffstat (limited to 'arch/xtensa')
| -rw-r--r-- | arch/xtensa/include/asm/uaccess.h | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/arch/xtensa/include/asm/uaccess.h b/arch/xtensa/include/asm/uaccess.h index 6792928ba84a..f568c00392ec 100644 --- a/arch/xtensa/include/asm/uaccess.h +++ b/arch/xtensa/include/asm/uaccess.h @@ -100,7 +100,7 @@ do { \ case 4: __put_user_asm(x, ptr, retval, 4, "s32i", __cb); break; \ case 8: { \ __typeof__(*ptr) __v64 = x; \ - retval = __copy_to_user(ptr, &__v64, 8); \ + retval = __copy_to_user(ptr, &__v64, 8) ? -EFAULT : 0; \ break; \ } \ default: __put_user_bad(); \ @@ -198,7 +198,16 @@ do { \ case 1: __get_user_asm(x, ptr, retval, 1, "l8ui", __cb); break;\ case 2: __get_user_asm(x, ptr, retval, 2, "l16ui", __cb); break;\ case 4: __get_user_asm(x, ptr, retval, 4, "l32i", __cb); break;\ - case 8: retval = __copy_from_user(&x, ptr, 8); break; \ + case 8: { \ + u64 __x; \ + if (unlikely(__copy_from_user(&__x, ptr, 8))) { \ + retval = -EFAULT; \ + (x) = 0; \ + } else { \ + (x) = *(__force __typeof__((ptr)))&__x; \ + } \ + break; \ + } \ default: (x) = __get_user_bad(); \ } \ } while (0) |