5.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Miklos Szeredi mszeredi@redhat.com
commit 1e08938c3694f707bb165535df352ac97a8c75c9 upstream.
The FUSE protocol uses struct fuse_write_out to convey the return value of copy_file_range, which is restricted to uint32_t. But the COPY_FILE_RANGE interface supports a 64-bit size copies.
Currently the number of bytes copied is silently truncated to 32-bit, which may result in poor performance or even failure to copy in case of truncation to zero.
Reported-by: Florian Weimer fweimer@redhat.com Closes: https://lore.kernel.org/all/lhuh5ynl8z5.fsf@oldenburg.str.redhat.com/ Fixes: 88bc7d5097a1 ("fuse: add support for copy_file_range()") Cc: stable@vger.kernel.org # v4.20 Signed-off-by: Miklos Szeredi mszeredi@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/fuse/file.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -3299,7 +3299,7 @@ static ssize_t __fuse_copy_file_range(st .nodeid_out = ff_out->nodeid, .fh_out = ff_out->fh, .off_out = pos_out, - .len = len, + .len = min_t(size_t, len, UINT_MAX & PAGE_MASK), .flags = flags }; struct fuse_write_out outarg;