From: "Theodore Ts'o" <tytso@mit.edu>
To: Ext4 Developers List <linux-ext4@vger.kernel.org>
Cc: "Theodore Ts'o" <tytso@mit.edu>, stable@kernel.org
Subject: [PATCH] ext4: fix signed vs unsigned comparison in ext4_valid_extent()
Date: Tue, 22 Oct 2019 21:31:12 -0400 [thread overview]
Message-ID: <20191023013112.18809-1-tytso@mit.edu> (raw)
Due to a signed vs unsigned comparison, an invalid extent where
ee_block (the logical block) is so large that lblk + len overflow
wasn't getting flagged as invalid.
As a result, we tripped the BUG_ON(end < lblk) in
ext4_es_cache_extent() when trying to mount a file system with a
corrupted journal inode was corrupted.
https://bugzilla.kernel.org/show_bug.cgi?id=205197
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
---
fs/ext4/extents.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index fb0f99dc8c22..d12bc287abdc 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -367,7 +367,7 @@ ext4_ext_max_entries(struct inode *inode, int depth)
static int ext4_valid_extent(struct inode *inode, struct ext4_extent *ext)
{
ext4_fsblk_t block = ext4_ext_pblock(ext);
- int len = ext4_ext_get_actual_len(ext);
+ unsigned int len = ext4_ext_get_actual_len(ext);
ext4_lblk_t lblock = le32_to_cpu(ext->ee_block);
/*
--
2.23.0
next reply other threads:[~2019-10-23 1:31 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-23 1:31 Theodore Ts'o [this message]
2019-10-23 5:44 ` [PATCH] ext4: fix signed vs unsigned comparison in ext4_valid_extent() Eric Biggers
2019-10-23 13:15 ` Theodore Y. Ts'o
2019-10-23 18:43 ` Ira Weiny
2019-10-23 19:46 ` Theodore Y. Ts'o
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