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Commit 53e0ee9f authored by Xiao Guangrong's avatar Xiao Guangrong Committed by Linus Torvalds
Browse files

splice: fix unexpected size truncation 



@splice_desc.total_len is 32 bit(unsigned int) which is used to store the
size passed from userspace which is 64 bit(size_t) so that the size is
unexpectedly truncated

That means vmsplice can not work if the size passed from userspace is >=
4G, for example, we noticed in vmsplice, splice-reader does not do
anything and splice-writer is waiting for available buffer forever if the
size is 4G

Fix it by extending @splice_desc.total_len to 64 bits as well

Signed-off-by: default avatarXiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent e7ca2552

include/linux/splice.h

+2 −1
Original line number Diff line number Diff line
@@ -24,7 +24,8 @@ 
 * Passed to the actors

 */

struct splice_desc {

	unsigned int len, total_len;	/* current and remaining length */

	size_t total_len;		/* remaining length */

	unsigned int len;		/* current length */

	unsigned int flags;		/* splice flags */

	/*

	 * actor() private data