* [PATCH] ext4: add more paranoia checking in ext4_expand_extra_isize handling
@ 2019-11-08 2:48 Theodore Ts'o
2019-11-10 10:12 ` kbuild test robot
0 siblings, 1 reply; 6+ messages in thread
From: Theodore Ts'o @ 2019-11-08 2:48 UTC (permalink / raw)
To: Ext4 Developers List
Cc: Theodore Ts'o, syzbot+f8d6f8386ceacdbfff57, stable
It's possible to specify a non-zero s_want_extra_isize via debugging
option, and this can cause bad things(tm) to happen when using a file
system with an inode size of 128 bytes.
Add better checking when the file system is mounted, as well as when
we are actually doing the trying to do the inode expansion.
Reported-by: syzbot+f8d6f8386ceacdbfff57@syzkaller.appspotmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
---
fs/ext4/inode.c | 14 ++++++++++++++
fs/ext4/super.c | 21 ++++++++++++---------
2 files changed, 26 insertions(+), 9 deletions(-)
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 381813205f99..84de97bc499e 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -5569,8 +5569,22 @@ static int __ext4_expand_extra_isize(struct inode *inode,
{
struct ext4_inode *raw_inode;
struct ext4_xattr_ibody_header *header;
+ unsigned int inode_size = EXT4_INODE_SIZE(inode->i_sb);
int error;
+ /* this was checked at iget time, but double check for good measure */
+ if ((EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize > inode_size) ||
+ (ei->i_extra_isize & 3)) {
+ EXT4_ERROR_INODE(inode, "bad extra_isize %u (inode size %u)",
+ ei->i_extra_isize,
+ EXT4_INODE_SIZE(inode->i_sb));
+ return -EFSCORRUPTED;
+ }
+ if ((new_extra_isize < ei->i_extra_size) ||
+ (new_extra_isize < 4) ||
+ (new_extra_size > inode_size - EXT4_GOOD_OLD_INODE_SIZE))
+ retun -EINVAL; /* Should never happen */
+
raw_inode = ext4_raw_inode(iloc);
header = IHDR(inode, raw_inode);
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 7796e2ffc294..71af8780d4ee 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -3545,12 +3545,15 @@ static void ext4_clamp_want_extra_isize(struct super_block *sb)
{
struct ext4_sb_info *sbi = EXT4_SB(sb);
struct ext4_super_block *es = sbi->s_es;
+ unsigned def_extra_isize = sizeof(struct ext4_inode) -
+ EXT4_GOOD_OLD_INODE_SIZE;
- /* determine the minimum size of new large inodes, if present */
- if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE &&
- sbi->s_want_extra_isize == 0) {
- sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
- EXT4_GOOD_OLD_INODE_SIZE;
+ if (sbi->s_inode_size == EXT4_GOOD_OLD_INODE_SIZE) {
+ sbi->s_want_extra_isize = 0;
+ return;
+ }
+ if (sbi->s_want_extra_isize < 4) {
+ sbi->s_want_extra_isize = def_extra_isize;
if (ext4_has_feature_extra_isize(sb)) {
if (sbi->s_want_extra_isize <
le16_to_cpu(es->s_want_extra_isize))
@@ -3563,10 +3566,10 @@ static void ext4_clamp_want_extra_isize(struct super_block *sb)
}
}
/* Check if enough inode space is available */
- if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
- sbi->s_inode_size) {
- sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
- EXT4_GOOD_OLD_INODE_SIZE;
+ if ((sbi->s_want_extra_isize > sbi->s_inode_size) ||
+ (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
+ sbi->s_inode_size)) {
+ sbi->s_want_extra_isize = def_extra_isize;
ext4_msg(sb, KERN_INFO,
"required extra inode space not available");
}
--
2.23.0
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH] ext4: add more paranoia checking in ext4_expand_extra_isize handling
2019-11-08 2:48 [PATCH] ext4: add more paranoia checking in ext4_expand_extra_isize handling Theodore Ts'o
@ 2019-11-10 10:12 ` kbuild test robot
2019-11-10 12:15 ` [PATCH -v2] " Theodore Y. Ts'o
0 siblings, 1 reply; 6+ messages in thread
From: kbuild test robot @ 2019-11-10 10:12 UTC (permalink / raw)
To: Theodore Ts'o
Cc: kbuild-all, Ext4 Developers List, Theodore Ts'o,
syzbot+f8d6f8386ceacdbfff57, stable
[-- Attachment #1: Type: text/plain, Size: 5175 bytes --]
Hi Theodore,
I love your patch! Perhaps something to improve:
[auto build test WARNING on ext4/dev]
[also build test WARNING on v5.4-rc6 next-20191108]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system. BTW, we also suggest to use '--base' option to specify the
base tree in git format-patch, please see https://stackoverflow.com/a/37406982]
url: https://github.com/0day-ci/linux/commits/Theodore-Ts-o/ext4-add-more-paranoia-checking-in-ext4_expand_extra_isize-handling/20191110-005324
base: https://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4.git dev
config: i386-randconfig-d003-201945 (attached as .config)
compiler: gcc-7 (Debian 7.4.0-14) 7.4.0
reproduce:
# save the attached .config to linux build tree
make ARCH=i386
If you fix the issue, kindly add following tag
Reported-by: kbuild test robot <lkp@intel.com>
All warnings (new ones prefixed by >>):
In file included from include/linux/export.h:44:0,
from include/linux/linkage.h:7,
from include/linux/fs.h:5,
from fs//ext4/inode.c:22:
fs//ext4/inode.c: In function '__ext4_expand_extra_isize':
fs//ext4/inode.c:5576:34: error: 'ei' undeclared (first use in this function)
if ((EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize > inode_size) ||
^
include/linux/compiler.h:58:52: note: in definition of macro '__trace_if_var'
#define __trace_if_var(cond) (__builtin_constant_p(cond) ? (cond) : __trace_if_value(cond))
^~~~
>> fs//ext4/inode.c:5576:2: note: in expansion of macro 'if'
if ((EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize > inode_size) ||
^~
fs//ext4/inode.c:5576:34: note: each undeclared identifier is reported only once for each function it appears in
if ((EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize > inode_size) ||
^
include/linux/compiler.h:58:52: note: in definition of macro '__trace_if_var'
#define __trace_if_var(cond) (__builtin_constant_p(cond) ? (cond) : __trace_if_value(cond))
^~~~
>> fs//ext4/inode.c:5576:2: note: in expansion of macro 'if'
if ((EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize > inode_size) ||
^~
fs//ext4/inode.c:5585:7: error: 'new_extra_size' undeclared (first use in this function); did you mean 'new_extra_isize'?
(new_extra_size > inode_size - EXT4_GOOD_OLD_INODE_SIZE))
^
include/linux/compiler.h:58:52: note: in definition of macro '__trace_if_var'
#define __trace_if_var(cond) (__builtin_constant_p(cond) ? (cond) : __trace_if_value(cond))
^~~~
fs//ext4/inode.c:5583:2: note: in expansion of macro 'if'
if ((new_extra_isize < ei->i_extra_size) ||
^~
fs//ext4/inode.c:5586:3: error: 'retun' undeclared (first use in this function); did you mean 'semun'?
retun -EINVAL; /* Should never happen */
^~~~~
semun
vim +/if +5576 fs//ext4/inode.c
5564
5565 static int __ext4_expand_extra_isize(struct inode *inode,
5566 unsigned int new_extra_isize,
5567 struct ext4_iloc *iloc,
5568 handle_t *handle, int *no_expand)
5569 {
5570 struct ext4_inode *raw_inode;
5571 struct ext4_xattr_ibody_header *header;
5572 unsigned int inode_size = EXT4_INODE_SIZE(inode->i_sb);
5573 int error;
5574
5575 /* this was checked at iget time, but double check for good measure */
> 5576 if ((EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize > inode_size) ||
5577 (ei->i_extra_isize & 3)) {
5578 EXT4_ERROR_INODE(inode, "bad extra_isize %u (inode size %u)",
5579 ei->i_extra_isize,
5580 EXT4_INODE_SIZE(inode->i_sb));
5581 return -EFSCORRUPTED;
5582 }
5583 if ((new_extra_isize < ei->i_extra_size) ||
5584 (new_extra_isize < 4) ||
5585 (new_extra_size > inode_size - EXT4_GOOD_OLD_INODE_SIZE))
5586 retun -EINVAL; /* Should never happen */
5587
5588 raw_inode = ext4_raw_inode(iloc);
5589
5590 header = IHDR(inode, raw_inode);
5591
5592 /* No extended attributes present */
5593 if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR) ||
5594 header->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC)) {
5595 memset((void *)raw_inode + EXT4_GOOD_OLD_INODE_SIZE +
5596 EXT4_I(inode)->i_extra_isize, 0,
5597 new_extra_isize - EXT4_I(inode)->i_extra_isize);
5598 EXT4_I(inode)->i_extra_isize = new_extra_isize;
5599 return 0;
5600 }
5601
5602 /* try to expand with EAs present */
5603 error = ext4_expand_extra_isize_ea(inode, new_extra_isize,
5604 raw_inode, handle);
5605 if (error) {
5606 /*
5607 * Inode size expansion failed; don't try again
5608 */
5609 *no_expand = 1;
5610 }
5611
5612 return error;
5613 }
5614
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org Intel Corporation
[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 38678 bytes --]
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH -v2] ext4: add more paranoia checking in ext4_expand_extra_isize handling
2019-11-10 10:12 ` kbuild test robot
@ 2019-11-10 12:15 ` Theodore Y. Ts'o
2019-11-19 2:15 ` Eric Biggers
0 siblings, 1 reply; 6+ messages in thread
From: Theodore Y. Ts'o @ 2019-11-10 12:15 UTC (permalink / raw)
To: kbuild test robot
Cc: kbuild-all, Ext4 Developers List, syzbot+f8d6f8386ceacdbfff57, stable
I hadn't gotten around to resending the patch. The original version
had a number of last-minute typos that had crept in...
- Ted
From a67ad537964d10f94a4b990c084365e75316cde8 Mon Sep 17 00:00:00 2001
From: Theodore Ts'o <tytso@mit.edu>
Date: Thu, 7 Nov 2019 21:43:41 -0500
Subject: [PATCH] ext4: add more paranoia checking in ext4_expand_extra_isize
handling
It's possible to specify a non-zero s_want_extra_isize via debugging
option, and this can cause bad things(tm) to happen when using a file
system with an inode size of 128 bytes.
Add better checking when the file system is mounted, as well as when
we are actually doing the trying to do the inode expansion.
Reported-by: syzbot+f8d6f8386ceacdbfff57@syzkaller.appspotmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
---
fs/ext4/inode.c | 15 +++++++++++++++
fs/ext4/super.c | 21 ++++++++++++---------
2 files changed, 27 insertions(+), 9 deletions(-)
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 381813205f99..c6e3fe287b50 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -5569,8 +5569,23 @@ static int __ext4_expand_extra_isize(struct inode *inode,
{
struct ext4_inode *raw_inode;
struct ext4_xattr_ibody_header *header;
+ unsigned int inode_size = EXT4_INODE_SIZE(inode->i_sb);
+ struct ext4_inode_info *ei = EXT4_I(inode);
int error;
+ /* this was checked at iget time, but double check for good measure */
+ if ((EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize > inode_size) ||
+ (ei->i_extra_isize & 3)) {
+ EXT4_ERROR_INODE(inode, "bad extra_isize %u (inode size %u)",
+ ei->i_extra_isize,
+ EXT4_INODE_SIZE(inode->i_sb));
+ return -EFSCORRUPTED;
+ }
+ if ((new_extra_isize < ei->i_extra_isize) ||
+ (new_extra_isize < 4) ||
+ (new_extra_isize > inode_size - EXT4_GOOD_OLD_INODE_SIZE))
+ return -EINVAL; /* Should never happen */
+
raw_inode = ext4_raw_inode(iloc);
header = IHDR(inode, raw_inode);
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 7796e2ffc294..71af8780d4ee 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -3545,12 +3545,15 @@ static void ext4_clamp_want_extra_isize(struct super_block *sb)
{
struct ext4_sb_info *sbi = EXT4_SB(sb);
struct ext4_super_block *es = sbi->s_es;
+ unsigned def_extra_isize = sizeof(struct ext4_inode) -
+ EXT4_GOOD_OLD_INODE_SIZE;
- /* determine the minimum size of new large inodes, if present */
- if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE &&
- sbi->s_want_extra_isize == 0) {
- sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
- EXT4_GOOD_OLD_INODE_SIZE;
+ if (sbi->s_inode_size == EXT4_GOOD_OLD_INODE_SIZE) {
+ sbi->s_want_extra_isize = 0;
+ return;
+ }
+ if (sbi->s_want_extra_isize < 4) {
+ sbi->s_want_extra_isize = def_extra_isize;
if (ext4_has_feature_extra_isize(sb)) {
if (sbi->s_want_extra_isize <
le16_to_cpu(es->s_want_extra_isize))
@@ -3563,10 +3566,10 @@ static void ext4_clamp_want_extra_isize(struct super_block *sb)
}
}
/* Check if enough inode space is available */
- if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
- sbi->s_inode_size) {
- sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
- EXT4_GOOD_OLD_INODE_SIZE;
+ if ((sbi->s_want_extra_isize > sbi->s_inode_size) ||
+ (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
+ sbi->s_inode_size)) {
+ sbi->s_want_extra_isize = def_extra_isize;
ext4_msg(sb, KERN_INFO,
"required extra inode space not available");
}
--
2.23.0
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH -v2] ext4: add more paranoia checking in ext4_expand_extra_isize handling
2019-11-10 12:15 ` [PATCH -v2] " Theodore Y. Ts'o
@ 2019-11-19 2:15 ` Eric Biggers
2019-11-19 4:21 ` Theodore Y. Ts'o
0 siblings, 1 reply; 6+ messages in thread
From: Eric Biggers @ 2019-11-19 2:15 UTC (permalink / raw)
To: Theodore Y. Ts'o
Cc: kbuild test robot, kbuild-all, Ext4 Developers List,
syzbot+f8d6f8386ceacdbfff57, stable
On Sun, Nov 10, 2019 at 07:15:10AM -0500, Theodore Y. Ts'o wrote:
> I hadn't gotten around to resending the patch. The original version
> had a number of last-minute typos that had crept in...
>
> - Ted
>
> From a67ad537964d10f94a4b990c084365e75316cde8 Mon Sep 17 00:00:00 2001
> From: Theodore Ts'o <tytso@mit.edu>
> Date: Thu, 7 Nov 2019 21:43:41 -0500
> Subject: [PATCH] ext4: add more paranoia checking in ext4_expand_extra_isize
> handling
>
>
> It's possible to specify a non-zero s_want_extra_isize via debugging
> option, and this can cause bad things(tm) to happen when using a file
> system with an inode size of 128 bytes.
>
> Add better checking when the file system is mounted, as well as when
> we are actually doing the trying to do the inode expansion.
>
> Reported-by: syzbot+f8d6f8386ceacdbfff57@syzkaller.appspotmail.com
> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
> Cc: stable@kernel.org
Is this patch intended to address
https://lore.kernel.org/linux-ext4/000000000000950f21059564e4c7@google.com
as well? If so, you can add the second Reported-by line so that both syzbot
reports get closed.
- Eric
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH -v2] ext4: add more paranoia checking in ext4_expand_extra_isize handling
2019-11-19 2:15 ` Eric Biggers
@ 2019-11-19 4:21 ` Theodore Y. Ts'o
2019-11-19 4:36 ` Eric Biggers
0 siblings, 1 reply; 6+ messages in thread
From: Theodore Y. Ts'o @ 2019-11-19 4:21 UTC (permalink / raw)
To: Eric Biggers
Cc: kbuild test robot, kbuild-all, Ext4 Developers List,
syzbot+f8d6f8386ceacdbfff57, stable
On Mon, Nov 18, 2019 at 06:15:26PM -0800, Eric Biggers wrote:
> Is this patch intended to address
> https://lore.kernel.org/linux-ext4/000000000000950f21059564e4c7@google.com
> as well? If so, you can add the second Reported-by line so that both syzbot
> reports get closed.
Yes, it appears to be the same issue. Thanks for pointing this out!
- Ted
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH -v2] ext4: add more paranoia checking in ext4_expand_extra_isize handling
2019-11-19 4:21 ` Theodore Y. Ts'o
@ 2019-11-19 4:36 ` Eric Biggers
0 siblings, 0 replies; 6+ messages in thread
From: Eric Biggers @ 2019-11-19 4:36 UTC (permalink / raw)
To: Theodore Y. Ts'o
Cc: kbuild test robot, kbuild-all, Ext4 Developers List,
syzbot+f8d6f8386ceacdbfff57, stable
On Mon, Nov 18, 2019 at 11:21:20PM -0500, Theodore Y. Ts'o wrote:
> On Mon, Nov 18, 2019 at 06:15:26PM -0800, Eric Biggers wrote:
> > Is this patch intended to address
> > https://lore.kernel.org/linux-ext4/000000000000950f21059564e4c7@google.com
> > as well? If so, you can add the second Reported-by line so that both syzbot
> > reports get closed.
>
> Yes, it appears to be the same issue. Thanks for pointing this out!
>
> - Ted
There's actually a third that looks very similar too:
"KASAN: use-after-free Write in __ext4_expand_extra_isize (2)"
https://lkml.kernel.org/linux-ext4/0000000000000d74c7059564e17f@google.com/
If these are all fixed by this patch, you can use:
Reported-by: syzbot+f8d6f8386ceacdbfff57@syzkaller.appspotmail.com
Reported-by: syzbot+33d7ea72e47de3bdf4e1@syzkaller.appspotmail.com
Reported-by: syzbot+44b6763edfc17144296f@syzkaller.appspotmail.com
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2019-11-19 4:36 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
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2019-11-08 2:48 [PATCH] ext4: add more paranoia checking in ext4_expand_extra_isize handling Theodore Ts'o
2019-11-10 10:12 ` kbuild test robot
2019-11-10 12:15 ` [PATCH -v2] " Theodore Y. Ts'o
2019-11-19 2:15 ` Eric Biggers
2019-11-19 4:21 ` Theodore Y. Ts'o
2019-11-19 4:36 ` Eric Biggers
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