From 8dd27fecede55e8a4e67eef2878040ecad0f0d33 Mon Sep 17 00:00:00 2001
From: Zhang Yi <yi.zhang@huawei.com>
Date: Wed, 8 Sep 2021 20:08:48 +0800
Subject: [PATCH] ext4: check for out-of-order index extents in
ext4_valid_extent_entries()
Git-commit: 8dd27fecede55e8a4e67eef2878040ecad0f0d33
Patch-mainline: v5.16-rc1
References: bsc#1194163 bsc#1196339
After commit 5946d089379a ("ext4: check for overlapping extents in
ext4_valid_extent_entries()"), we can check out the overlapping extent
entry in leaf extent blocks. But the out-of-order extent entry in index
extent blocks could also trigger bad things if the filesystem is
inconsistent. So this patch add a check to figure out the out-of-order
index extents and return error.
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Link: https://lore.kernel.org/r/20210908120850.4012324-2-yi.zhang@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Acked-by: Jan Kara <jack@suse.cz>
---
fs/ext4/extents.c | 20 ++++++++++++++------
1 file changed, 14 insertions(+), 6 deletions(-)
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -405,6 +405,10 @@ static int ext4_valid_extent_entries(str
int depth)
{
unsigned short entries;
+ ext4_lblk_t lblock = 0;
+ ext4_lblk_t prev = 0;
+ ext4_fsblk_t pblock = 0;
+
if (eh->eh_entries == 0)
return 1;
@@ -414,33 +418,37 @@ static int ext4_valid_extent_entries(str
/* leaf entries */
struct ext4_extent *ext = EXT_FIRST_EXTENT(eh);
struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
- ext4_fsblk_t pblock = 0;
- ext4_lblk_t lblock = 0;
- ext4_lblk_t prev = 0;
- int len = 0;
while (entries) {
if (!ext4_valid_extent(inode, ext))
return 0;
/* Check for overlapping extents */
lblock = le32_to_cpu(ext->ee_block);
- len = ext4_ext_get_actual_len(ext);
if ((lblock <= prev) && prev) {
pblock = ext4_ext_pblock(ext);
es->s_last_error_block = cpu_to_le64(pblock);
return 0;
}
+ prev = lblock + ext4_ext_get_actual_len(ext) - 1;
ext++;
entries--;
- prev = lblock + len - 1;
}
} else {
struct ext4_extent_idx *ext_idx = EXT_FIRST_INDEX(eh);
while (entries) {
if (!ext4_valid_extent_idx(inode, ext_idx))
return 0;
+
+ /* Check for overlapping index extents */
+ lblock = le32_to_cpu(ext_idx->ei_block);
+ if ((lblock <= prev) && prev) {
+ pblock = ext4_idx_pblock(ext_idx);
+ es->s_last_error_block = cpu_to_le64(pblock);
+ return 0;
+ }
ext_idx++;
entries--;
+ prev = lblock;
}
}
return 1;