From f5f7ab168b9a60e12a4b8f2bb6fcc91321dc23c1 Mon Sep 17 00:00:00 2001

From: "Matthew Wilcox (Oracle)" <willy@infradead.org>

Date: Sun, 4 Oct 2020 19:04:22 +0100

Subject: [PATCH] 9P: Cast to loff_t before multiplying

Git-commit: f5f7ab168b9a60e12a4b8f2bb6fcc91321dc23c1

Patch-mainline: v5.10-rc1

References: git-fixes

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: fb89b45cdfdc ("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>

Acked-by: Takashi Iwai <tiwai@suse.de>

---

 fs/9p/vfs_file.c | 4 ++--

 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c

index 3576123d8299..6d97b6b4d34b 100644

--- a/fs/9p/vfs_file.c

+++ b/fs/9p/vfs_file.c

@@ -612,9 +612,9 @@ 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),

 	};

-- 

2.16.4