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-rw-r--r--arch/x86/include/asm/uaccess.h12
-rw-r--r--drivers/gpu/drm/i915/i915_gem_execbuffer.c16
-rw-r--r--include/linux/uaccess.h2
-rw-r--r--kernel/compat.c6
-rw-r--r--kernel/exit.c6
-rw-r--r--lib/strncpy_from_user.c9
-rw-r--r--lib/strnlen_user.c9
7 files changed, 40 insertions, 20 deletions
diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h
index 971830341061..d871e424fa50 100644
--- a/arch/x86/include/asm/uaccess.h
+++ b/arch/x86/include/asm/uaccess.h
@@ -711,7 +711,17 @@ extern struct movsl_mask {
* checking before using them, but you have to surround them with the
* user_access_begin/end() pair.
*/
-#define user_access_begin() __uaccess_begin()
+static __must_check inline bool user_access_begin(int type,
+ const void __user *ptr,
+ size_t len)
+{
+ if (unlikely(!access_ok(type, ptr, len)))
+ return 0;
+ __uaccess_begin();
+ return 1;
+}
+
+#define user_access_begin(a, b, c) user_access_begin(a, b, c)
#define user_access_end() __uaccess_end()
#define unsafe_put_user(x, ptr, err_label) \
diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
index f08c54740cbe..52894816167c 100644
--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -1604,7 +1604,9 @@ static int eb_copy_relocations(const struct i915_execbuffer *eb)
* happened we would make the mistake of assuming that the
* relocations were valid.
*/
- user_access_begin();
+ if (!user_access_begin(VERIFY_WRITE, urelocs, size))
+ goto end_user;
+
for (copied = 0; copied < nreloc; copied++)
unsafe_put_user(-1,
&urelocs[copied].presumed_offset,
@@ -2649,7 +2651,17 @@ i915_gem_execbuffer2_ioctl(struct drm_device *dev, void *data,
unsigned int i;
/* Copy the new buffer offsets back to the user's exec list. */
- user_access_begin();
+ /*
+ * Note: count * sizeof(*user_exec_list) does not overflow,
+ * because we checked 'count' in check_buffer_count().
+ *
+ * And this range already got effectively checked earlier
+ * when we did the "copy_from_user()" above.
+ */
+ if (!user_access_begin(VERIFY_WRITE, user_exec_list,
+ count * sizeof(*user_exec_list)))
+ goto end_user;
+
for (i = 0; i < args->buffer_count; i++) {
if (!(exec2_list[i].offset & UPDATE))
continue;
diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h
index efe79c1cdd47..d55b68b113de 100644
--- a/include/linux/uaccess.h
+++ b/include/linux/uaccess.h
@@ -267,7 +267,7 @@ extern long strncpy_from_unsafe(char *dst, const void *unsafe_addr, long count);
probe_kernel_read(&retval, addr, sizeof(retval))
#ifndef user_access_begin
-#define user_access_begin() do { } while (0)
+#define user_access_begin(type, ptr, len) access_ok(type, ptr, len)
#define user_access_end() do { } while (0)
#define unsafe_get_user(x, ptr, err) do { if (unlikely(__get_user(x, ptr))) goto err; } while (0)
#define unsafe_put_user(x, ptr, err) do { if (unlikely(__put_user(x, ptr))) goto err; } while (0)
diff --git a/kernel/compat.c b/kernel/compat.c
index 8e40efc2928a..e4548a9e9c52 100644
--- a/kernel/compat.c
+++ b/kernel/compat.c
@@ -354,10 +354,9 @@ long compat_get_bitmap(unsigned long *mask, const compat_ulong_t __user *umask,
bitmap_size = ALIGN(bitmap_size, BITS_PER_COMPAT_LONG);
nr_compat_longs = BITS_TO_COMPAT_LONGS(bitmap_size);
- if (!access_ok(VERIFY_READ, umask, bitmap_size / 8))
+ if (!user_access_begin(VERIFY_READ, umask, bitmap_size / 8))
return -EFAULT;
- user_access_begin();
while (nr_compat_longs > 1) {
compat_ulong_t l1, l2;
unsafe_get_user(l1, umask++, Efault);
@@ -384,10 +383,9 @@ long compat_put_bitmap(compat_ulong_t __user *umask, unsigned long *mask,
bitmap_size = ALIGN(bitmap_size, BITS_PER_COMPAT_LONG);
nr_compat_longs = BITS_TO_COMPAT_LONGS(bitmap_size);
- if (!access_ok(VERIFY_WRITE, umask, bitmap_size / 8))
+ if (!user_access_begin(VERIFY_WRITE, umask, bitmap_size / 8))
return -EFAULT;
- user_access_begin();
while (nr_compat_longs > 1) {
unsigned long m = *mask++;
unsafe_put_user((compat_ulong_t)m, umask++, Efault);
diff --git a/kernel/exit.c b/kernel/exit.c
index 54c3269b8dda..894fca56a38c 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -1617,10 +1617,9 @@ SYSCALL_DEFINE5(waitid, int, which, pid_t, upid, struct siginfo __user *,
if (!infop)
return err;
- if (!access_ok(VERIFY_WRITE, infop, sizeof(*infop)))
+ if (!user_access_begin(VERIFY_WRITE, infop, sizeof(*infop)))
return -EFAULT;
- user_access_begin();
unsafe_put_user(signo, &infop->si_signo, Efault);
unsafe_put_user(0, &infop->si_errno, Efault);
unsafe_put_user(info.cause, &infop->si_code, Efault);
@@ -1745,10 +1744,9 @@ COMPAT_SYSCALL_DEFINE5(waitid,
if (!infop)
return err;
- if (!access_ok(VERIFY_WRITE, infop, sizeof(*infop)))
+ if (!user_access_begin(VERIFY_WRITE, infop, sizeof(*infop)))
return -EFAULT;
- user_access_begin();
unsafe_put_user(signo, &infop->si_signo, Efault);
unsafe_put_user(0, &infop->si_errno, Efault);
unsafe_put_user(info.cause, &infop->si_code, Efault);
diff --git a/lib/strncpy_from_user.c b/lib/strncpy_from_user.c
index e304b54c9c7d..b8570a11776d 100644
--- a/lib/strncpy_from_user.c
+++ b/lib/strncpy_from_user.c
@@ -115,10 +115,11 @@ long strncpy_from_user(char *dst, const char __user *src, long count)
kasan_check_write(dst, count);
check_object_size(dst, count, false);
- user_access_begin();
- retval = do_strncpy_from_user(dst, src, count, max);
- user_access_end();
- return retval;
+ if (user_access_begin(VERIFY_READ, src, max)) {
+ retval = do_strncpy_from_user(dst, src, count, max);
+ user_access_end();
+ return retval;
+ }
}
return -EFAULT;
}
diff --git a/lib/strnlen_user.c b/lib/strnlen_user.c
index 184f80f7bacf..f5fa5b266ea2 100644
--- a/lib/strnlen_user.c
+++ b/lib/strnlen_user.c
@@ -114,10 +114,11 @@ long strnlen_user(const char __user *str, long count)
unsigned long max = max_addr - src_addr;
long retval;
- user_access_begin();
- retval = do_strnlen_user(str, count, max);
- user_access_end();
- return retval;
+ if (user_access_begin(VERIFY_READ, str, max)) {
+ retval = do_strnlen_user(str, count, max);
+ user_access_end();
+ return retval;
+ }
}
return 0;
}
generated by cgit v1.2.3 (git 2.39.1) at 2024-07-04 11:21:34 +0000