Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit b8590c82 authored by Rustam Kovhaev's avatar Rustam Kovhaev Committed by Greg Kroah-Hartman
Browse files

reiserfs: add check for an invalid ih_entry_count 

commit d24396c5290ba8ab04ba505176874c4e04a2d53c upstream.

when directory item has an invalid value set for ih_entry_count it might
trigger use-after-free or out-of-bounds read in bin_search_in_dir_item()

ih_entry_count * IH_SIZE for directory item should not be larger than
ih_item_len

Link: https://lore.kernel.org/r/20201101140958.3650143-1-rkovhaev@gmail.com


Reported-and-tested-by: default avatar <syzbot+83b6f7cf9922cae5c4d7@syzkaller.appspotmail.com>
Link: https://syzkaller.appspot.com/bug?extid=83b6f7cf9922cae5c4d7


Signed-off-by: default avatarRustam Kovhaev <rkovhaev@gmail.com>
Signed-off-by: default avatarJan Kara <jack@suse.cz>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 88520a20

fs/reiserfs/stree.c

+6 −0
Original line number Diff line number Diff line
@@ -454,6 +454,12 @@ static int is_leaf(char *buf, int blocksize, struct buffer_head *bh) 
					 "(second one): %h", ih);

			return 0;

		}

		if (is_direntry_le_ih(ih) && (ih_item_len(ih) < (ih_entry_count(ih) * IH_SIZE))) {

			reiserfs_warning(NULL, "reiserfs-5093",

					 "item entry count seems wrong %h",

					 ih);

			return 0;

		}

		prev_location = ih_location(ih);

	}