The patch titled
Subject: reiserfs: add check for an invalid ih_entry_count
has been added to the -mm tree. Its filename is
reiserfs-add-check-for-an-invalid-ih_entry_count.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/reiserfs-add-check-for-an-invalid-ih_entry_count.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/reiserfs-add-check-for-an-invalid-ih_entry_count.patch
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------------------------------------------------------
From: Rustam Kovhaev <rkovhaev@xxxxxxxxx>
Subject: 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
Reported-and-tested-by: syzbot+83b6f7cf9922cae5c4d7@xxxxxxxxxxxxxxxxxxxxxxxxx
Link: https://syzkaller.appspot.com/bug?extid=83b6f7cf9922cae5c4d7
Link: https://lkml.kernel.org/r/20201101140958.3650143-1-rkovhaev@xxxxxxxxx
Signed-off-by: Rustam Kovhaev <rkovhaev@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/reiserfs/stree.c | 6 ++++++
1 file changed, 6 insertions(+)
--- a/fs/reiserfs/stree.c~reiserfs-add-check-for-an-invalid-ih_entry_count
+++ a/fs/reiserfs/stree.c
@@ -454,6 +454,12 @@ static int is_leaf(char *buf, int blocks
"(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);
}
_
Patches currently in -mm which might be from rkovhaev@xxxxxxxxx are
reiserfs-add-check-for-an-invalid-ih_entry_count.patch
