Commit f8708955 authored Oct 04, 2020 by Matthew Wilcox (Oracle) Committed by Greg Kroah-Hartman Nov 05, 2020

9P: Cast to loff_t before multiplying

commit f5f7ab168b9a60e12a4b8f2bb6fcc91321dc23c1 upstream.

On 32-bit systems, this multiplication will overflow for files larger
than 4GB.

Link: http://lkml.kernel.org/r/20201004180428.14494-2-willy@infradead.org


Cc: stable@vger.kernel.org
Fixes: fb89b45c ("9P: introduction of a new cache=mmap model.")
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 416ea978

fs/9p/vfs_file.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -624,9 +624,9 @@ static void v9fs_mmap_vm_close(struct vm_area_struct *vma)
		struct writeback_control wbc = {
		.nr_to_write = LONG_MAX,
		.sync_mode = WB_SYNC_ALL,
		.range_start = vma->vm_pgoff * PAGE_SIZE,
		.range_start = (loff_t)vma->vm_pgoff * PAGE_SIZE,
		/* absolute end, byte at end included */
		.range_end = vma->vm_pgoff * PAGE_SIZE +
		.range_end = (loff_t)vma->vm_pgoff * PAGE_SIZE +
		(vma->vm_end - vma->vm_start - 1),
		};