From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 From: Daniel Axtens Date: Mon, 18 Jan 2021 16:49:09 +1100 Subject: [PATCH] fs/nilfs2: Reject too-large keys NILFS2 has up to 7 keys, per the data structure. Do not permit array indices in excess of that. This catches some OOB reads. I don't know how controllable the invalidly read data is or if that could be used later in the program. Signed-off-by: Daniel Axtens Reviewed-by: Daniel Kiper --- grub-core/fs/nilfs2.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/grub-core/fs/nilfs2.c b/grub-core/fs/nilfs2.c index 598a2a55b..61e8af9ff 100644 --- a/grub-core/fs/nilfs2.c +++ b/grub-core/fs/nilfs2.c @@ -569,6 +569,11 @@ grub_nilfs2_btree_lookup (struct grub_nilfs2_data *data, static inline grub_uint64_t grub_nilfs2_direct_lookup (struct grub_nilfs2_inode *inode, grub_uint64_t key) { + if (1 + key > 6) + { + grub_error (GRUB_ERR_BAD_FS, "key is too large"); + return 0xffffffffffffffff; + } return grub_le_to_cpu64 (inode->i_bmap[1 + key]); } @@ -584,7 +589,7 @@ grub_nilfs2_bmap_lookup (struct grub_nilfs2_data *data, { grub_uint64_t ptr; ptr = grub_nilfs2_direct_lookup (inode, key); - if (need_translate) + if (ptr != ((grub_uint64_t) 0xffffffffffffffff) && need_translate) ptr = grub_nilfs2_dat_translate (data, ptr); return ptr; }