0104-fs-hfsplus-Don-t-fetch-a-key-beyond-the-end-of-the-n.patch 1.1 KB

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  1. From 58ea11d5b9ca0966bd9c68d8ba5240cf7dc3ba83 Mon Sep 17 00:00:00 2001
  2. From: Daniel Axtens <dja@axtens.net>
  3. Date: Fri, 22 Jan 2021 18:13:56 +1100
  4. Subject: [PATCH] fs/hfsplus: Don't fetch a key beyond the end of the node
  5. Otherwise you get a wild pointer, leading to a bunch of invalid reads.
  6. Check it falls inside the given node.
  7. Signed-off-by: Daniel Axtens <dja@axtens.net>
  8. Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
  9. Signed-off-by: Stefan Sørensen <stefan.sorensen@spectralink.com>
  10. ---
  11. grub-core/fs/hfsplus.c | 4 ++++
  12. 1 file changed, 4 insertions(+)
  13. diff --git a/grub-core/fs/hfsplus.c b/grub-core/fs/hfsplus.c
  14. index 8fe7c12..1c7791b 100644
  15. --- a/grub-core/fs/hfsplus.c
  16. +++ b/grub-core/fs/hfsplus.c
  17. @@ -635,6 +635,10 @@ grub_hfsplus_btree_search (struct grub_hfsplus_btree *btree,
  18. pointer = ((char *) currkey
  19. + grub_be_to_cpu16 (currkey->keylen)
  20. + 2);
  21. +
  22. + if ((char *) pointer > node + btree->nodesize - 2)
  23. + return grub_error (GRUB_ERR_BAD_FS, "HFS+ key beyond end of node");
  24. +
  25. currnode = grub_be_to_cpu32 (grub_get_unaligned32 (pointer));
  26. match = 1;
  27. }
  28. --
  29. 2.14.2