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Commit 8811930d authored by Jens Axboe's avatar Jens Axboe Committed by Linus Torvalds
Browse files

splice: missing user pointer access verification 



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: default avatarJens Axboe <jens.axboe@oracle.com>
Cc: Wojciech Purczynski <cliph@research.coseinc.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 66191dc6

fs/splice.c

+8 −0
Original line number Diff line number Diff line
@@ -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;