| From foo@baz Mon Dec 18 15:03:25 CET 2017 |
| From: David Howells <dhowells@redhat.com> |
| Date: Thu, 16 Mar 2017 16:27:47 +0000 |
| Subject: afs: Fix the maths in afs_fs_store_data() |
| |
| From: David Howells <dhowells@redhat.com> |
| |
| |
| [ Upstream commit 146a1192783697810b63a1e41c4d59fc93387340 ] |
| |
| afs_fs_store_data() works out of the size of the write it's going to make, |
| but it uses 32-bit unsigned subtraction in one place that gets |
| automatically cast to loff_t. |
| |
| However, if to < offset, then the number goes negative, but as the result |
| isn't signed, this doesn't get sign-extended to 64-bits when placed in a |
| loff_t. |
| |
| Fix by casting the operands to loff_t. |
| |
| Signed-off-by: David Howells <dhowells@redhat.com> |
| Signed-off-by: Sasha Levin <alexander.levin@verizon.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| fs/afs/fsclient.c | 2 +- |
| 1 file changed, 1 insertion(+), 1 deletion(-) |
| |
| --- a/fs/afs/fsclient.c |
| +++ b/fs/afs/fsclient.c |
| @@ -1225,7 +1225,7 @@ int afs_fs_store_data(struct afs_server |
| _enter(",%x,{%x:%u},,", |
| key_serial(wb->key), vnode->fid.vid, vnode->fid.vnode); |
| |
| - size = to - offset; |
| + size = (loff_t)to - (loff_t)offset; |
| if (first != last) |
| size += (loff_t)(last - first) << PAGE_SHIFT; |
| pos = (loff_t)first << PAGE_SHIFT; |