38 lines
1.6 KiB
Diff
38 lines
1.6 KiB
Diff
|
From 52b7cd6e9a701bb203023d56e84551943dc6a4c0 Mon Sep 17 00:00:00 2001
|
||
|
|
From: Adam Maris <amaris@redhat.com>
|
||
|
|
Date: Thu, 14 Mar 2019 16:51:16 -0400
|
||
|
|
Subject: [PATCH 18] malloc: Check for large bin list corruption when
|
||
|
|
inserting unsorted chunk
|
||
|
|
|
||
|
|
Fixes bug 24216. This patch adds security checks for bk and bk_nextsize pointers
|
||
|
|
of chunks in large bin when inserting chunk from unsorted bin. It was possible
|
||
|
|
to write the pointer to victim (newly inserted chunk) to arbitrary memory
|
||
|
|
locations if bk or bk_nextsize pointers of the next large bin chunk
|
||
|
|
got corrupted.
|
||
|
|
|
||
|
|
(cherry picked from commit 5b06f538c5aee0389ed034f60d90a8884d6d54de)
|
||
|
|
---
|
||
|
|
malloc/malloc.c | 4 ++++
|
||
|
|
1 file changed, 4 insertions(+)
|
||
|
|
|
||
|
|
diff --git a/malloc/malloc.c b/malloc/malloc.c
|
||
|
|
index feaf7ee0bf..ce771375b6 100644
|
||
|
|
--- a/malloc/malloc.c
|
||
|
|
+++ b/malloc/malloc.c
|
||
|
|
@@ -3876,10 +3876,14 @@ _int_malloc (mstate av, size_t bytes)
|
||
|
|
{
|
||
|
|
victim->fd_nextsize = fwd;
|
||
|
|
victim->bk_nextsize = fwd->bk_nextsize;
|
||
|
|
+ if (__glibc_unlikely (fwd->bk_nextsize->fd_nextsize != fwd))
|
||
|
|
+ malloc_printerr ("malloc(): largebin double linked list corrupted (nextsize)");
|
||
|
|
fwd->bk_nextsize = victim;
|
||
|
|
victim->bk_nextsize->fd_nextsize = victim;
|
||
|
|
}
|
||
|
|
bck = fwd->bk;
|
||
|
|
+ if (bck->fd != fwd)
|
||
|
|
+ malloc_printerr ("malloc(): largebin double linked list corrupted (bk)");
|
||
|
|
}
|
||
|
|
}
|
||
|
|
else
|
||
|
|
|