From 97744669e0e6c31e76182010f25451ccda5abe86 Mon Sep 17 00:00:00 2001 From: Zach Brown Date: Tue, 24 Jul 2012 12:10:11 -0700 Subject: fuse: verify all ioctl retry iov elements commit fb6ccff667712c46b4501b920ea73a326e49626a upstream. Commit 7572777eef78ebdee1ecb7c258c0ef94d35bad16 attempted to verify that the total iovec from the client doesn't overflow iov_length() but it only checked the first element. The iovec could still overflow by starting with a small element. The obvious fix is to check all the elements. The overflow case doesn't look dangerous to the kernel as the copy is limited by the length after the overflow. This fix restores the intention of returning an error instead of successfully copying less than the iovec represented. I found this by code inspection. I built it but don't have a test case. I'm cc:ing stable because the initial commit did as well. Signed-off-by: Zach Brown Signed-off-by: Miklos Szeredi Signed-off-by: Greg Kroah-Hartman Signed-off-by: Willy Tarreau --- fs/fuse/file.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/fuse') diff --git a/fs/fuse/file.c b/fs/fuse/file.c index f6104a958812..102d58297174 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -1664,7 +1664,7 @@ static int fuse_verify_ioctl_iov(struct iovec *iov, size_t count) size_t n; u32 max = FUSE_MAX_PAGES_PER_REQ << PAGE_SHIFT; - for (n = 0; n < count; n++) { + for (n = 0; n < count; n++, iov++) { if (iov->iov_len > (size_t) max) return -ENOMEM; max -= iov->iov_len; -- cgit v1.2.3