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authorDavid Howells <dhowells@redhat.com>2017-03-16 16:27:47 +0000
committerDavid Howells <dhowells@redhat.com>2017-03-16 16:27:47 +0000
commit146a1192783697810b63a1e41c4d59fc93387340 (patch)
treef96b12c641b60681eeac2bfd612c8532793e6420
parent2f5705a5c805e7f761f2228820656bb9363a3d8c (diff)
afs: Fix the maths in afs_fs_store_data()
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>
-rw-r--r--fs/afs/fsclient.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/afs/fsclient.c b/fs/afs/fsclient.c
index 0778c5b6b59b..d9234b767287 100644
--- a/fs/afs/fsclient.c
+++ b/fs/afs/fsclient.c
@@ -1236,7 +1236,7 @@ int afs_fs_store_data(struct afs_server *server, struct afs_writeback *wb,
_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;