1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
|
From ac48bb9bc0a32f5a4432be1645b57607f8c46aa7 Mon Sep 17 00:00:00 2001
From: Theodore Ts'o <tytso@mit.edu>
Date: Wed, 13 Jun 2018 23:00:48 -0400
Subject: [PATCH] ext4: always check block group bounds in
ext4_init_block_bitmap()
commit 819b23f1c501b17b9694325471789e6b5cc2d0d2 upstream.
Regardless of whether the flex_bg feature is set, we should always
check to make sure the bits we are setting in the block bitmap are
within the block group bounds.
https://bugzilla.kernel.org/show_bug.cgi?id=199865
CVE: CVE-2018-10878
Upstream-Status: Backport [https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?h=linux-4.14.y&id=ac48bb9bc0a32f5a4432be1645b57607f8c46aa7]
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andreas Wellving <andreas.wellving@enea.com>
---
fs/ext4/balloc.c | 10 +++-------
1 file changed, 3 insertions(+), 7 deletions(-)
diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c
index 58db8109defa..3149aee77b6b 100644
--- a/fs/ext4/balloc.c
+++ b/fs/ext4/balloc.c
@@ -184,7 +184,6 @@ static int ext4_init_block_bitmap(struct super_block *sb,
unsigned int bit, bit_max;
struct ext4_sb_info *sbi = EXT4_SB(sb);
ext4_fsblk_t start, tmp;
- int flex_bg = 0;
struct ext4_group_info *grp;
J_ASSERT_BH(bh, buffer_locked(bh));
@@ -217,22 +216,19 @@ static int ext4_init_block_bitmap(struct super_block *sb,
start = ext4_group_first_block_no(sb, block_group);
- if (ext4_has_feature_flex_bg(sb))
- flex_bg = 1;
-
/* Set bits for block and inode bitmaps, and inode table */
tmp = ext4_block_bitmap(sb, gdp);
- if (!flex_bg || ext4_block_in_group(sb, tmp, block_group))
+ if (ext4_block_in_group(sb, tmp, block_group))
ext4_set_bit(EXT4_B2C(sbi, tmp - start), bh->b_data);
tmp = ext4_inode_bitmap(sb, gdp);
- if (!flex_bg || ext4_block_in_group(sb, tmp, block_group))
+ if (ext4_block_in_group(sb, tmp, block_group))
ext4_set_bit(EXT4_B2C(sbi, tmp - start), bh->b_data);
tmp = ext4_inode_table(sb, gdp);
for (; tmp < ext4_inode_table(sb, gdp) +
sbi->s_itb_per_group; tmp++) {
- if (!flex_bg || ext4_block_in_group(sb, tmp, block_group))
+ if (ext4_block_in_group(sb, tmp, block_group))
ext4_set_bit(EXT4_B2C(sbi, tmp - start), bh->b_data);
}
--
2.20.1
|
