Please consider the two upstream commits below for the 4.14.y
branch.
As a part of an automated test setup, we deploy a disk image into
various types of hardware. With the current 4.14.y kernel and
certain hardware configurations, the first attempt to write the
image to the disk always fails with 'Remote I/O error'. Retrying
the exact same command then always succeeds. The second patch
below fixes this issue allowing the first attempt to work. It
requires the first patch to compile without errors.
commit 425a4dba7953e35ffd096771973add6d2f40d2ed
Author: Ilya Dryomov <idryomov(a)gmail.com>
Date: Mon Oct 16 15:59:09 2017 +0200
block: factor out __blkdev_issue_zero_pages()
commit d5ce4c31d6df518dd8f63bbae20d7423c5018a6c
Author: Ilya Dryomov <idryomov(a)gmail.com>
Date: Mon Oct 16 15:59:10 2017 +0200
block: cope with WRITE ZEROES failing in blkdev_issue_zeroout()
The patch below does not apply to the 4.17-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From db6516a5e7ddb6dc72d167b920f2f272596ea22d Mon Sep 17 00:00:00 2001
From: Amir Goldstein <amir73il(a)gmail.com>
Date: Sun, 13 May 2018 22:54:44 -0400
Subject: [PATCH] ext4: do not update s_last_mounted of a frozen fs
If fs is frozen after mount and before the first file open, the
update of s_last_mounted bypasses freeze protection and prints out
a WARNING splat:
$ mount /vdf
$ fsfreeze -f /vdf
$ cat /vdf/foo
[ 31.578555] WARNING: CPU: 1 PID: 1415 at
fs/ext4/ext4_jbd2.c:53 ext4_journal_check_start+0x48/0x82
[ 31.614016] Call Trace:
[ 31.614997] __ext4_journal_start_sb+0xe4/0x1a4
[ 31.616771] ? ext4_file_open+0xb6/0x189
[ 31.618094] ext4_file_open+0xb6/0x189
If fs is frozen, skip s_last_mounted update.
[backport hint: to apply to stable tree, need to apply also patches
vfs: add the sb_start_intwrite_trylock() helper
ext4: factor out helper ext4_sample_last_mounted()]
Cc: stable(a)vger.kernel.org
Fixes: bc0b0d6d69ee ("ext4: update the s_last_mounted field in the superblock")
Signed-off-by: Amir Goldstein <amir73il(a)gmail.com>
Signed-off-by: Theodore Ts'o <tytso(a)mit.edu>
Reviewed-by: Jan Kara <jack(a)suse.cz>
diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index c48ea76b63e4..7f8023340eb8 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -393,7 +393,7 @@ static int ext4_sample_last_mounted(struct super_block *sb,
if (likely(sbi->s_mount_flags & EXT4_MF_MNTDIR_SAMPLED))
return 0;
- if (sb_rdonly(sb))
+ if (sb_rdonly(sb) || !sb_start_intwrite_trylock(sb))
return 0;
sbi->s_mount_flags |= EXT4_MF_MNTDIR_SAMPLED;
@@ -407,21 +407,25 @@ static int ext4_sample_last_mounted(struct super_block *sb,
path.mnt = mnt;
path.dentry = mnt->mnt_root;
cp = d_path(&path, buf, sizeof(buf));
+ err = 0;
if (IS_ERR(cp))
- return 0;
+ goto out;
handle = ext4_journal_start_sb(sb, EXT4_HT_MISC, 1);
+ err = PTR_ERR(handle);
if (IS_ERR(handle))
- return PTR_ERR(handle);
+ goto out;
BUFFER_TRACE(sbi->s_sbh, "get_write_access");
err = ext4_journal_get_write_access(handle, sbi->s_sbh);
if (err)
- goto out;
+ goto out_journal;
strlcpy(sbi->s_es->s_last_mounted, cp,
sizeof(sbi->s_es->s_last_mounted));
ext4_handle_dirty_super(handle, sb);
-out:
+out_journal:
ext4_journal_stop(handle);
+out:
+ sb_end_intwrite(sb);
return err;
}
The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 8bc1379b82b8e809eef77a9fedbb75c6c297be19 Mon Sep 17 00:00:00 2001
From: Theodore Ts'o <tytso(a)mit.edu>
Date: Sat, 16 Jun 2018 23:41:59 -0400
Subject: [PATCH] ext4: avoid running out of journal credits when appending to
an inline file
Use a separate journal transaction if it turns out that we need to
convert an inline file to use an data block. Otherwise we could end
up failing due to not having journal credits.
This addresses CVE-2018-10883.
https://bugzilla.kernel.org/show_bug.cgi?id=200071
Signed-off-by: Theodore Ts'o <tytso(a)mit.edu>
Cc: stable(a)kernel.org
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 856b6a54d82b..859d6433dcc1 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -3013,9 +3013,6 @@ extern int ext4_inline_data_fiemap(struct inode *inode,
struct iomap;
extern int ext4_inline_data_iomap(struct inode *inode, struct iomap *iomap);
-extern int ext4_try_to_evict_inline_data(handle_t *handle,
- struct inode *inode,
- int needed);
extern int ext4_inline_data_truncate(struct inode *inode, int *has_inline);
extern int ext4_convert_inline_data(struct inode *inode);
diff --git a/fs/ext4/inline.c b/fs/ext4/inline.c
index d79115d8d716..851bc552d849 100644
--- a/fs/ext4/inline.c
+++ b/fs/ext4/inline.c
@@ -887,11 +887,11 @@ int ext4_da_write_inline_data_begin(struct address_space *mapping,
flags |= AOP_FLAG_NOFS;
if (ret == -ENOSPC) {
+ ext4_journal_stop(handle);
ret = ext4_da_convert_inline_data_to_extent(mapping,
inode,
flags,
fsdata);
- ext4_journal_stop(handle);
if (ret == -ENOSPC &&
ext4_should_retry_alloc(inode->i_sb, &retries))
goto retry_journal;
@@ -1891,42 +1891,6 @@ int ext4_inline_data_fiemap(struct inode *inode,
return (error < 0 ? error : 0);
}
-/*
- * Called during xattr set, and if we can sparse space 'needed',
- * just create the extent tree evict the data to the outer block.
- *
- * We use jbd2 instead of page cache to move data to the 1st block
- * so that the whole transaction can be committed as a whole and
- * the data isn't lost because of the delayed page cache write.
- */
-int ext4_try_to_evict_inline_data(handle_t *handle,
- struct inode *inode,
- int needed)
-{
- int error;
- struct ext4_xattr_entry *entry;
- struct ext4_inode *raw_inode;
- struct ext4_iloc iloc;
-
- error = ext4_get_inode_loc(inode, &iloc);
- if (error)
- return error;
-
- raw_inode = ext4_raw_inode(&iloc);
- entry = (struct ext4_xattr_entry *)((void *)raw_inode +
- EXT4_I(inode)->i_inline_off);
- if (EXT4_XATTR_LEN(entry->e_name_len) +
- EXT4_XATTR_SIZE(le32_to_cpu(entry->e_value_size)) < needed) {
- error = -ENOSPC;
- goto out;
- }
-
- error = ext4_convert_inline_data_nolock(handle, inode, &iloc);
-out:
- brelse(iloc.bh);
- return error;
-}
-
int ext4_inline_data_truncate(struct inode *inode, int *has_inline)
{
handle_t *handle;
diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
index 72377b77fbd7..723df14f4084 100644
--- a/fs/ext4/xattr.c
+++ b/fs/ext4/xattr.c
@@ -2212,23 +2212,8 @@ int ext4_xattr_ibody_inline_set(handle_t *handle, struct inode *inode,
if (EXT4_I(inode)->i_extra_isize == 0)
return -ENOSPC;
error = ext4_xattr_set_entry(i, s, handle, inode, false /* is_block */);
- if (error) {
- if (error == -ENOSPC &&
- ext4_has_inline_data(inode)) {
- error = ext4_try_to_evict_inline_data(handle, inode,
- EXT4_XATTR_LEN(strlen(i->name) +
- EXT4_XATTR_SIZE(i->value_len)));
- if (error)
- return error;
- error = ext4_xattr_ibody_find(inode, i, is);
- if (error)
- return error;
- error = ext4_xattr_set_entry(i, s, handle, inode,
- false /* is_block */);
- }
- if (error)
- return error;
- }
+ if (error)
+ return error;
header = IHDR(inode, ext4_raw_inode(&is->iloc));
if (!IS_LAST_ENTRY(s->first)) {
header->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC);
The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 8bc1379b82b8e809eef77a9fedbb75c6c297be19 Mon Sep 17 00:00:00 2001
From: Theodore Ts'o <tytso(a)mit.edu>
Date: Sat, 16 Jun 2018 23:41:59 -0400
Subject: [PATCH] ext4: avoid running out of journal credits when appending to
an inline file
Use a separate journal transaction if it turns out that we need to
convert an inline file to use an data block. Otherwise we could end
up failing due to not having journal credits.
This addresses CVE-2018-10883.
https://bugzilla.kernel.org/show_bug.cgi?id=200071
Signed-off-by: Theodore Ts'o <tytso(a)mit.edu>
Cc: stable(a)kernel.org
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 856b6a54d82b..859d6433dcc1 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -3013,9 +3013,6 @@ extern int ext4_inline_data_fiemap(struct inode *inode,
struct iomap;
extern int ext4_inline_data_iomap(struct inode *inode, struct iomap *iomap);
-extern int ext4_try_to_evict_inline_data(handle_t *handle,
- struct inode *inode,
- int needed);
extern int ext4_inline_data_truncate(struct inode *inode, int *has_inline);
extern int ext4_convert_inline_data(struct inode *inode);
diff --git a/fs/ext4/inline.c b/fs/ext4/inline.c
index d79115d8d716..851bc552d849 100644
--- a/fs/ext4/inline.c
+++ b/fs/ext4/inline.c
@@ -887,11 +887,11 @@ int ext4_da_write_inline_data_begin(struct address_space *mapping,
flags |= AOP_FLAG_NOFS;
if (ret == -ENOSPC) {
+ ext4_journal_stop(handle);
ret = ext4_da_convert_inline_data_to_extent(mapping,
inode,
flags,
fsdata);
- ext4_journal_stop(handle);
if (ret == -ENOSPC &&
ext4_should_retry_alloc(inode->i_sb, &retries))
goto retry_journal;
@@ -1891,42 +1891,6 @@ int ext4_inline_data_fiemap(struct inode *inode,
return (error < 0 ? error : 0);
}
-/*
- * Called during xattr set, and if we can sparse space 'needed',
- * just create the extent tree evict the data to the outer block.
- *
- * We use jbd2 instead of page cache to move data to the 1st block
- * so that the whole transaction can be committed as a whole and
- * the data isn't lost because of the delayed page cache write.
- */
-int ext4_try_to_evict_inline_data(handle_t *handle,
- struct inode *inode,
- int needed)
-{
- int error;
- struct ext4_xattr_entry *entry;
- struct ext4_inode *raw_inode;
- struct ext4_iloc iloc;
-
- error = ext4_get_inode_loc(inode, &iloc);
- if (error)
- return error;
-
- raw_inode = ext4_raw_inode(&iloc);
- entry = (struct ext4_xattr_entry *)((void *)raw_inode +
- EXT4_I(inode)->i_inline_off);
- if (EXT4_XATTR_LEN(entry->e_name_len) +
- EXT4_XATTR_SIZE(le32_to_cpu(entry->e_value_size)) < needed) {
- error = -ENOSPC;
- goto out;
- }
-
- error = ext4_convert_inline_data_nolock(handle, inode, &iloc);
-out:
- brelse(iloc.bh);
- return error;
-}
-
int ext4_inline_data_truncate(struct inode *inode, int *has_inline)
{
handle_t *handle;
diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
index 72377b77fbd7..723df14f4084 100644
--- a/fs/ext4/xattr.c
+++ b/fs/ext4/xattr.c
@@ -2212,23 +2212,8 @@ int ext4_xattr_ibody_inline_set(handle_t *handle, struct inode *inode,
if (EXT4_I(inode)->i_extra_isize == 0)
return -ENOSPC;
error = ext4_xattr_set_entry(i, s, handle, inode, false /* is_block */);
- if (error) {
- if (error == -ENOSPC &&
- ext4_has_inline_data(inode)) {
- error = ext4_try_to_evict_inline_data(handle, inode,
- EXT4_XATTR_LEN(strlen(i->name) +
- EXT4_XATTR_SIZE(i->value_len)));
- if (error)
- return error;
- error = ext4_xattr_ibody_find(inode, i, is);
- if (error)
- return error;
- error = ext4_xattr_set_entry(i, s, handle, inode,
- false /* is_block */);
- }
- if (error)
- return error;
- }
+ if (error)
+ return error;
header = IHDR(inode, ext4_raw_inode(&is->iloc));
if (!IS_LAST_ENTRY(s->first)) {
header->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC);
The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 8cdb5240ec5928b20490a2bb34cb87e9a5f40226 Mon Sep 17 00:00:00 2001
From: Theodore Ts'o <tytso(a)mit.edu>
Date: Sat, 16 Jun 2018 15:40:48 -0400
Subject: [PATCH] ext4: never move the system.data xattr out of the inode body
When expanding the extra isize space, we must never move the
system.data xattr out of the inode body. For performance reasons, it
doesn't make any sense, and the inline data implementation assumes
that system.data xattr is never in the external xattr block.
This addresses CVE-2018-10880
https://bugzilla.kernel.org/show_bug.cgi?id=200005
Signed-off-by: Theodore Ts'o <tytso(a)mit.edu>
Cc: stable(a)kernel.org
diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
index 0263692979ec..72377b77fbd7 100644
--- a/fs/ext4/xattr.c
+++ b/fs/ext4/xattr.c
@@ -2657,6 +2657,11 @@ static int ext4_xattr_make_inode_space(handle_t *handle, struct inode *inode,
last = IFIRST(header);
/* Find the entry best suited to be pushed into EA block */
for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
+ /* never move system.data out of the inode */
+ if ((last->e_name_len == 4) &&
+ (last->e_name_index == EXT4_XATTR_INDEX_SYSTEM) &&
+ !memcmp(last->e_name, "data", 4))
+ continue;
total_size = EXT4_XATTR_LEN(last->e_name_len);
if (!last->e_value_inum)
total_size += EXT4_XATTR_SIZE(
The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 8cdb5240ec5928b20490a2bb34cb87e9a5f40226 Mon Sep 17 00:00:00 2001
From: Theodore Ts'o <tytso(a)mit.edu>
Date: Sat, 16 Jun 2018 15:40:48 -0400
Subject: [PATCH] ext4: never move the system.data xattr out of the inode body
When expanding the extra isize space, we must never move the
system.data xattr out of the inode body. For performance reasons, it
doesn't make any sense, and the inline data implementation assumes
that system.data xattr is never in the external xattr block.
This addresses CVE-2018-10880
https://bugzilla.kernel.org/show_bug.cgi?id=200005
Signed-off-by: Theodore Ts'o <tytso(a)mit.edu>
Cc: stable(a)kernel.org
diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
index 0263692979ec..72377b77fbd7 100644
--- a/fs/ext4/xattr.c
+++ b/fs/ext4/xattr.c
@@ -2657,6 +2657,11 @@ static int ext4_xattr_make_inode_space(handle_t *handle, struct inode *inode,
last = IFIRST(header);
/* Find the entry best suited to be pushed into EA block */
for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
+ /* never move system.data out of the inode */
+ if ((last->e_name_len == 4) &&
+ (last->e_name_index == EXT4_XATTR_INDEX_SYSTEM) &&
+ !memcmp(last->e_name, "data", 4))
+ continue;
total_size = EXT4_XATTR_LEN(last->e_name_len);
if (!last->e_value_inum)
total_size += EXT4_XATTR_SIZE(
The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 513f86d73855ce556ea9522b6bfd79f87356dc3a Mon Sep 17 00:00:00 2001
From: Theodore Ts'o <tytso(a)mit.edu>
Date: Wed, 13 Jun 2018 00:51:28 -0400
Subject: [PATCH] ext4: always verify the magic number in xattr blocks
If there an inode points to a block which is also some other type of
metadata block (such as a block allocation bitmap), the
buffer_verified flag can be set when it was validated as that other
metadata block type; however, it would make a really terrible external
attribute block. The reason why we use the verified flag is to avoid
constantly reverifying the block. However, it doesn't take much
overhead to make sure the magic number of the xattr block is correct,
and this will avoid potential crashes.
This addresses CVE-2018-10879.
https://bugzilla.kernel.org/show_bug.cgi?id=200001
Signed-off-by: Theodore Ts'o <tytso(a)mit.edu>
Reviewed-by: Andreas Dilger <adilger(a)dilger.ca>
Cc: stable(a)kernel.org
diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
index 230ba79715f6..0263692979ec 100644
--- a/fs/ext4/xattr.c
+++ b/fs/ext4/xattr.c
@@ -230,12 +230,12 @@ __ext4_xattr_check_block(struct inode *inode, struct buffer_head *bh,
{
int error = -EFSCORRUPTED;
- if (buffer_verified(bh))
- return 0;
-
if (BHDR(bh)->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC) ||
BHDR(bh)->h_blocks != cpu_to_le32(1))
goto errout;
+ if (buffer_verified(bh))
+ return 0;
+
error = -EFSBADCRC;
if (!ext4_xattr_block_csum_verify(inode, bh))
goto errout;
The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 513f86d73855ce556ea9522b6bfd79f87356dc3a Mon Sep 17 00:00:00 2001
From: Theodore Ts'o <tytso(a)mit.edu>
Date: Wed, 13 Jun 2018 00:51:28 -0400
Subject: [PATCH] ext4: always verify the magic number in xattr blocks
If there an inode points to a block which is also some other type of
metadata block (such as a block allocation bitmap), the
buffer_verified flag can be set when it was validated as that other
metadata block type; however, it would make a really terrible external
attribute block. The reason why we use the verified flag is to avoid
constantly reverifying the block. However, it doesn't take much
overhead to make sure the magic number of the xattr block is correct,
and this will avoid potential crashes.
This addresses CVE-2018-10879.
https://bugzilla.kernel.org/show_bug.cgi?id=200001
Signed-off-by: Theodore Ts'o <tytso(a)mit.edu>
Reviewed-by: Andreas Dilger <adilger(a)dilger.ca>
Cc: stable(a)kernel.org
diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
index 230ba79715f6..0263692979ec 100644
--- a/fs/ext4/xattr.c
+++ b/fs/ext4/xattr.c
@@ -230,12 +230,12 @@ __ext4_xattr_check_block(struct inode *inode, struct buffer_head *bh,
{
int error = -EFSCORRUPTED;
- if (buffer_verified(bh))
- return 0;
-
if (BHDR(bh)->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC) ||
BHDR(bh)->h_blocks != cpu_to_le32(1))
goto errout;
+ if (buffer_verified(bh))
+ return 0;
+
error = -EFSBADCRC;
if (!ext4_xattr_block_csum_verify(inode, bh))
goto errout;
The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 5369a762c882c0b6e9599e4ebbb3a9ba9eee7e2d Mon Sep 17 00:00:00 2001
From: Theodore Ts'o <tytso(a)mit.edu>
Date: Wed, 13 Jun 2018 00:23:11 -0400
Subject: [PATCH] ext4: add corruption check in ext4_xattr_set_entry()
In theory this should have been caught earlier when the xattr list was
verified, but in case it got missed, it's simple enough to add check
to make sure we don't overrun the xattr buffer.
This addresses CVE-2018-10879.
https://bugzilla.kernel.org/show_bug.cgi?id=200001
Signed-off-by: Theodore Ts'o <tytso(a)mit.edu>
Reviewed-by: Andreas Dilger <adilger(a)dilger.ca>
Cc: stable(a)kernel.org
diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
index fc4ced59c565..230ba79715f6 100644
--- a/fs/ext4/xattr.c
+++ b/fs/ext4/xattr.c
@@ -1560,7 +1560,7 @@ static int ext4_xattr_set_entry(struct ext4_xattr_info *i,
handle_t *handle, struct inode *inode,
bool is_block)
{
- struct ext4_xattr_entry *last;
+ struct ext4_xattr_entry *last, *next;
struct ext4_xattr_entry *here = s->here;
size_t min_offs = s->end - s->base, name_len = strlen(i->name);
int in_inode = i->in_inode;
@@ -1595,7 +1595,13 @@ static int ext4_xattr_set_entry(struct ext4_xattr_info *i,
/* Compute min_offs and last. */
last = s->first;
- for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
+ for (; !IS_LAST_ENTRY(last); last = next) {
+ next = EXT4_XATTR_NEXT(last);
+ if ((void *)next >= s->end) {
+ EXT4_ERROR_INODE(inode, "corrupted xattr entries");
+ ret = -EFSCORRUPTED;
+ goto out;
+ }
if (!last->e_value_inum && last->e_value_size) {
size_t offs = le16_to_cpu(last->e_value_offs);
if (offs < min_offs)
The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 5369a762c882c0b6e9599e4ebbb3a9ba9eee7e2d Mon Sep 17 00:00:00 2001
From: Theodore Ts'o <tytso(a)mit.edu>
Date: Wed, 13 Jun 2018 00:23:11 -0400
Subject: [PATCH] ext4: add corruption check in ext4_xattr_set_entry()
In theory this should have been caught earlier when the xattr list was
verified, but in case it got missed, it's simple enough to add check
to make sure we don't overrun the xattr buffer.
This addresses CVE-2018-10879.
https://bugzilla.kernel.org/show_bug.cgi?id=200001
Signed-off-by: Theodore Ts'o <tytso(a)mit.edu>
Reviewed-by: Andreas Dilger <adilger(a)dilger.ca>
Cc: stable(a)kernel.org
diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
index fc4ced59c565..230ba79715f6 100644
--- a/fs/ext4/xattr.c
+++ b/fs/ext4/xattr.c
@@ -1560,7 +1560,7 @@ static int ext4_xattr_set_entry(struct ext4_xattr_info *i,
handle_t *handle, struct inode *inode,
bool is_block)
{
- struct ext4_xattr_entry *last;
+ struct ext4_xattr_entry *last, *next;
struct ext4_xattr_entry *here = s->here;
size_t min_offs = s->end - s->base, name_len = strlen(i->name);
int in_inode = i->in_inode;
@@ -1595,7 +1595,13 @@ static int ext4_xattr_set_entry(struct ext4_xattr_info *i,
/* Compute min_offs and last. */
last = s->first;
- for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
+ for (; !IS_LAST_ENTRY(last); last = next) {
+ next = EXT4_XATTR_NEXT(last);
+ if ((void *)next >= s->end) {
+ EXT4_ERROR_INODE(inode, "corrupted xattr entries");
+ ret = -EFSCORRUPTED;
+ goto out;
+ }
if (!last->e_value_inum && last->e_value_size) {
size_t offs = le16_to_cpu(last->e_value_offs);
if (offs < min_offs)