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| author | Rustam Kovhaev <rkovhaev@gmail.com> | 2020-11-01 06:09:58 -0800 |
|---|---|---|
| committer | Jan Kara <jack@suse.cz> | 2020-11-26 16:57:28 +0100 |
| commit | d24396c5290ba8ab04ba505176874c4e04a2d53c (patch) | |
| tree | 0d6db3f24d2c3ad33148c2246215f3010cb6f963 /fs/reiserfs | |
| parent | 8fca3c8a3451514c6f20dd26d5e66e78220d16e3 (diff) | |
| download | lwn-d24396c5290ba8ab04ba505176874c4e04a2d53c.tar.gz lwn-d24396c5290ba8ab04ba505176874c4e04a2d53c.zip | |
reiserfs: add check for an invalid ih_entry_count
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: syzbot+83b6f7cf9922cae5c4d7@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?extid=83b6f7cf9922cae5c4d7
Signed-off-by: Rustam Kovhaev <rkovhaev@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Diffstat (limited to 'fs/reiserfs')
| -rw-r--r-- | fs/reiserfs/stree.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/fs/reiserfs/stree.c b/fs/reiserfs/stree.c index 8bf88d690729..476a7ff49482 100644 --- a/fs/reiserfs/stree.c +++ b/fs/reiserfs/stree.c @@ -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); } |