5.4-stable review patch. If anyone has any objections, please let me know.
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From: Miklos Szeredi mszeredi@redhat.com
commit e5203209b3935041dac541bc5b37efb44220cc0b upstream.
Just like write(), copy_file_range() should check if the return value is less or equal to the requested number of bytes.
Reported-by: Chunsheng Luo luochunsheng@ustc.edu Closes: https://lore.kernel.org/all/20250807062425.694-1-luochunsheng@ustc.edu/ 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 | 3 +++ 1 file changed, 3 insertions(+)
--- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -3365,6 +3365,9 @@ static ssize_t __fuse_copy_file_range(st fc->no_copy_file_range = 1; err = -EOPNOTSUPP; } + if (!err && outarg.size > len) + err = -EIO; + if (err) goto out;