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authorRustam Kovhaev <rkovhaev@gmail.com>2020-11-01 06:09:58 -0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2021-01-06 14:45:00 +0100
commitb8590c82b3ccf9fb4d9f0b0b097be10736869333 (patch)
tree786eb7adfcc7ced676927d081631046c35eb5bba
parent88520a207121c3f7c513ac69a7392da89ed0955f (diff)
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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: 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--fs/reiserfs/stree.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/fs/reiserfs/stree.c b/fs/reiserfs/stree.c
index 2946713cb00d..5229038852ca 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);
}