From: Miklos Szeredi <mszeredi@redhat.com>
Date: Tue, 12 Nov 2019 11:49:04 +0100
Subject: fuse: verify write return
Git-commit: 8aab336b14c115c6bf1d4baeb9247e41ed9ce6de
Patch-mainline: v5.5-rc1
References: jsc#SLE-13782
Make sure filesystem is not returning a bogus number of bytes written.
Fixes: ea9b9907b82a ("fuse: implement perform_write")
Cc: <stable@vger.kernel.org> # v2.6.26
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Acked-by: Luis Henriques <lhenriques@suse.com>
---
fs/fuse/file.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index db48a5cf8620..795d0f24d8b4 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -1096,6 +1096,8 @@ static ssize_t fuse_send_write_pages(struct fuse_io_args *ia,
ia->write.in.flags = fuse_write_flags(iocb);
err = fuse_simple_request(fc, &ap->args);
+ if (!err && ia->write.out.size > count)
+ err = -EIO;
offset = ap->descs[0].offset;
count = ia->write.out.size;