4.9-stable review patch. If anyone has any objections, please let me know.
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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 @@ -1178,7 +1178,7 @@ 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;