From 6c9a3f843a29d6894dfc40df338b91dbd78f0ae3 Mon Sep 17 00:00:00 2001
From: Colin Ian King <colin.king@canonical.com>
Date: Tue, 30 Oct 2018 15:06:35 -0700
Subject: [PATCH] fs/hfs/extent.c: fix array out of bounds read of array extent
Git-commit: 6c9a3f843a29d6894dfc40df338b91dbd78f0ae3
Patch-mainline: v4.20-rc1
References: git-fixes
Currently extent and index i are both being incremented causing an array
out of bounds read on extent[i]. Fix this by removing the extraneous
increment of extent.
Ernesto said:
: This is only triggered when deleting a file with a resource fork. I
: may be wrong because the documentation isn't clear, but I don't think
: you can create those under linux. So I guess nobody was testing them.
:
: > A disk space leak, perhaps?
: That's what it looks like in general. hfs_free_extents() won't do
: anything if the block count doesn't add up, and the error will be
: ignored. Now, if the block count randomly does add up, we could see
: some corruption.
Detected by CoverityScan, CID#711541 ("Out of bounds read")
Link: http://lkml.kernel.org/r/20180831140538.31566-1-colin.king@canonical.com
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Ernesto A. Fernndez <ernesto.mnd.fernandez@gmail.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Hin-Tak Leung <htl10@users.sourceforge.net>
Cc: Vyacheslav Dubeyko <slava@dubeyko.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Anthony Iliopoulos <ailiop@suse.com>
---
fs/hfs/extent.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/hfs/extent.c b/fs/hfs/extent.c
index 5f1ff97a3b98..263d5028d9d1 100644
--- a/fs/hfs/extent.c
+++ b/fs/hfs/extent.c
@@ -304,7 +304,7 @@ int hfs_free_fork(struct super_block *sb, struct hfs_cat_file *file, int type)
return 0;
blocks = 0;
- for (i = 0; i < 3; extent++, i++)
+ for (i = 0; i < 3; i++)
blocks += be16_to_cpu(extent[i].count);
res = hfs_free_extents(sb, extent, blocks, blocks);
--
2.35.3