From 356c74f00ed24b08810dc236f37caaca228e5853 Mon Sep 17 00:00:00 2001 From: Daniel Axtens Date: Mon, 18 Jan 2021 17:17:16 +1100 Subject: [PATCH] fs/btrfs: Validate the number of stripes/parities in RAID5/6 This prevents a divide by zero if nstripes == nparities, and also prevents propagation of invalid values if nstripes ends up less than nparities. Reference: http://git.savannah.gnu.org/cgit/grub.git/commit/?id=b88a82e78cdd0ab8e0339c1c3f9564c4d8c0c969 Signed-off-by: Daniel Axtens Reviewed-by: Daniel Kiper --- grub-core/fs/btrfs.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/grub-core/fs/btrfs.c b/grub-core/fs/btrfs.c index 0d8c666..a6384a8 100644 --- a/grub-core/fs/btrfs.c +++ b/grub-core/fs/btrfs.c @@ -1105,6 +1105,9 @@ grub_btrfs_read_logical (struct grub_btrfs_data *data, grub_disk_addr_t addr, * stripen is computed without the parities * (0 for A0, A1, A2, 1 for B0, B1, B2, etc.). */ + if (nparities >= nstripes) + return grub_error (GRUB_ERR_BAD_FS, + "invalid RAID5/6: nparities >= nstripes"); high = grub_divmod64 (stripe_nr, nstripes - nparities, &stripen); /* -- 2.19.1