0111-fs-nilfs2-Reject-too-large-keys.patch 1.5 KB

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  1. From 20ab8cb44bc140a1dedda82a3fccdd45e9bc6929 Mon Sep 17 00:00:00 2001
  2. From: Daniel Axtens <dja@axtens.net>
  3. Date: Mon, 18 Jan 2021 16:49:09 +1100
  4. Subject: [PATCH] fs/nilfs2: Reject too-large keys
  5. NILFS2 has up to 7 keys, per the data structure. Do not permit array
  6. indices in excess of that.
  7. This catches some OOB reads. I don't know how controllable the invalidly
  8. read data is or if that could be used later in the program.
  9. Signed-off-by: Daniel Axtens <dja@axtens.net>
  10. Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
  11. Signed-off-by: Stefan Sørensen <stefan.sorensen@spectralink.com>
  12. ---
  13. grub-core/fs/nilfs2.c | 7 ++++++-
  14. 1 file changed, 6 insertions(+), 1 deletion(-)
  15. diff --git a/grub-core/fs/nilfs2.c b/grub-core/fs/nilfs2.c
  16. index 7ed148d..fee2242 100644
  17. --- a/grub-core/fs/nilfs2.c
  18. +++ b/grub-core/fs/nilfs2.c
  19. @@ -569,6 +569,11 @@ grub_nilfs2_btree_lookup (struct grub_nilfs2_data *data,
  20. static inline grub_uint64_t
  21. grub_nilfs2_direct_lookup (struct grub_nilfs2_inode *inode, grub_uint64_t key)
  22. {
  23. + if (1 + key > 6)
  24. + {
  25. + grub_error (GRUB_ERR_BAD_FS, "key is too large");
  26. + return 0xffffffffffffffff;
  27. + }
  28. return grub_le_to_cpu64 (inode->i_bmap[1 + key]);
  29. }
  30. @@ -584,7 +589,7 @@ grub_nilfs2_bmap_lookup (struct grub_nilfs2_data *data,
  31. {
  32. grub_uint64_t ptr;
  33. ptr = grub_nilfs2_direct_lookup (inode, key);
  34. - if (need_translate)
  35. + if (ptr != ((grub_uint64_t) 0xffffffffffffffff) && need_translate)
  36. ptr = grub_nilfs2_dat_translate (data, ptr);
  37. return ptr;
  38. }
  39. --
  40. 2.14.2