1*4882a593SmuzhiyunFrom b88a82e78cdd0ab8e0339c1c3f9564c4d8c0c969 Mon Sep 17 00:00:00 2001
2*4882a593SmuzhiyunFrom: Daniel Axtens <dja@axtens.net>
3*4882a593SmuzhiyunDate: Mon, 18 Jan 2021 17:17:16 +1100
4*4882a593SmuzhiyunSubject: [PATCH] fs/btrfs: Validate the number of stripes/parities in RAID5/6
5*4882a593Smuzhiyun
6*4882a593SmuzhiyunThis prevents a divide by zero if nstripes == nparities, and
7*4882a593Smuzhiyunalso prevents propagation of invalid values if nstripes ends up
8*4882a593Smuzhiyunless than nparities.
9*4882a593Smuzhiyun
10*4882a593SmuzhiyunSigned-off-by: Daniel Axtens <dja@axtens.net>
11*4882a593SmuzhiyunReviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
12*4882a593SmuzhiyunSigned-off-by: Stefan Sørensen <stefan.sorensen@spectralink.com>
13*4882a593Smuzhiyun---
14*4882a593Smuzhiyun grub-core/fs/btrfs.c | 3 +++
15*4882a593Smuzhiyun 1 file changed, 3 insertions(+)
16*4882a593Smuzhiyun
17*4882a593Smuzhiyundiff --git a/grub-core/fs/btrfs.c b/grub-core/fs/btrfs.c
18*4882a593Smuzhiyunindex 2b65bd5..e4e87ba 100644
19*4882a593Smuzhiyun--- a/grub-core/fs/btrfs.c
20*4882a593Smuzhiyun+++ b/grub-core/fs/btrfs.c
21*4882a593Smuzhiyun@@ -1076,6 +1076,9 @@ grub_btrfs_read_logical (struct grub_btrfs_data *data, grub_disk_addr_t addr,
22*4882a593Smuzhiyun 	       * stripen is computed without the parities
23*4882a593Smuzhiyun 	       * (0 for A0, A1, A2, 1 for B0, B1, B2, etc.).
24*4882a593Smuzhiyun 	       */
25*4882a593Smuzhiyun+	      if (nparities >= nstripes)
26*4882a593Smuzhiyun+		return grub_error (GRUB_ERR_BAD_FS,
27*4882a593Smuzhiyun+				   "invalid RAID5/6: nparities >= nstripes");
28*4882a593Smuzhiyun 	      high = grub_divmod64 (stripe_nr, nstripes - nparities, &stripen);
29*4882a593Smuzhiyun
30*4882a593Smuzhiyun 	      /*
31*4882a593Smuzhiyun--
32*4882a593Smuzhiyun2.14.2
33*4882a593Smuzhiyun
34