| Subject | [PATCH v2 56/67] afs: Fix afs_write_end() to handle len > page size | From | David Howells <> | Date | Thu, 09 Dec 2021 17:08:06 +0000 |
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It is possible for the len argument to afs_write_end() to overrun the end of the page (len is used to key the size of the page in afs_write_start() when compound pages become a regular thing).
Fix afs_write_end() to correctly trim the write length so that it doesn't exceed the end of the page.
Fixes: 3003bbd0697b ("afs: Use the netfs_write_begin() helper") Reported-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Jeff Layton <jlayton@kernel.org> cc: Marc Dionne <marc.dionne@auristor.com> cc: Al Viro <viro@zeniv.linux.org.uk> cc: Matthew Wilcox <willy@infradead.org> cc: linux-afs@lists.infradead.org Link: https://lore.kernel.org/r/162367682522.460125.5652091227576721609.stgit@warthog.procyon.org.uk/ # v1 Link: https://lore.kernel.org/r/163819660464.215744.4576104569408497052.stgit@warthog.procyon.org.uk/ # v1 ---
fs/afs/write.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/fs/afs/write.c b/fs/afs/write.c index 8e4e87d66855..9db3ddb1c45b 100644 --- a/fs/afs/write.c +++ b/fs/afs/write.c @@ -120,6 +120,7 @@ int afs_write_end(struct file *file, struct address_space *mapping, _enter("{%llx:%llu},{%lx}", vnode->fid.vid, vnode->fid.vnode, folio_index(folio)); + len = min_t(size_t, len, folio_size(folio) - from); if (!folio_test_uptodate(folio)) { if (copied < len) { copied = 0;
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