1From 58ea11d5b9ca0966bd9c68d8ba5240cf7dc3ba83 Mon Sep 17 00:00:00 2001
2From: Daniel Axtens <dja@axtens.net>
3Date: Fri, 22 Jan 2021 18:13:56 +1100
4Subject: [PATCH] fs/hfsplus: Don't fetch a key beyond the end of the node
5
6Otherwise you get a wild pointer, leading to a bunch of invalid reads.
7Check it falls inside the given node.
8
9Signed-off-by: Daniel Axtens <dja@axtens.net>
10Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
11Signed-off-by: Stefan Sørensen <stefan.sorensen@spectralink.com>
12---
13 grub-core/fs/hfsplus.c | 4 ++++
14 1 file changed, 4 insertions(+)
15
16diff --git a/grub-core/fs/hfsplus.c b/grub-core/fs/hfsplus.c
17index 8fe7c12..1c7791b 100644
18--- a/grub-core/fs/hfsplus.c
19+++ b/grub-core/fs/hfsplus.c
20@@ -635,6 +635,10 @@ grub_hfsplus_btree_search (struct grub_hfsplus_btree *btree,
21 	      pointer = ((char *) currkey
22 			 + grub_be_to_cpu16 (currkey->keylen)
23 			 + 2);
24+
25+	      if ((char *) pointer > node + btree->nodesize - 2)
26+		return grub_error (GRUB_ERR_BAD_FS, "HFS+ key beyond end of node");
27+
28 	      currnode = grub_be_to_cpu32 (grub_get_unaligned32 (pointer));
29 	      match = 1;
30 	    }
31--
322.14.2
33
34