From: Jens Axboe <[EMAIL PROTECTED]>
vmsplice_to_user() must always check the user pointer and length
with access_ok() before copying. Likewise, for the slow path of
copy_from_user_mmap_sem() we need to check that we may read from
the user region.
Signed-off-by: Jens Axboe <[EMAIL PROTECTED]>
Cc: Wojciech Purczynski <[EMAIL PROTECTED]>
Signed-off-by: Greg Kroah-Hartman <[EMAIL PROTECTED]>
---
Linus, this fixes a security hole in splice that is now public. I have
it queued up for the .23 and .24 -stable releases as well.
fs/splice.c | 8 ++++++++
1 files changed, 8 insertions(+), 0 deletions(-)
diff --git a/fs/splice.c b/fs/splice.c
index 4ee49e8..14e2262 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -1179,6 +1179,9 @@ static int copy_from_user_mmap_sem(void *dst, const void
__user *src, size_t n)
{
int partial;
+ if (!access_ok(VERIFY_READ, src, n))
+ return -EFAULT;
+
pagefault_disable();
partial = __copy_from_user_inatomic(dst, src, n);
pagefault_enable();
@@ -1387,6 +1390,11 @@ static long vmsplice_to_user(struct file *file, const
struct iovec __user *iov,
break;
}
+ if (unlikely(!access_ok(VERIFY_WRITE, base, len))) {
+ error = -EFAULT;
+ break;
+ }
+
sd.len = 0;
sd.total_len = len;
sd.flags = flags;
--
1.5.4.22.g7a20
--
Jens Axboe
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
