diff mbox series

[v2,1/2] generic: add test for race between listxattr and setxatr

Message ID 20200822114132.61227-1-houtao1@huawei.com (mailing list archive)
State New, archived
Headers show
Series [v2,1/2] generic: add test for race between listxattr and setxatr | expand

Commit Message

Hou Tao Aug. 22, 2020, 11:41 a.m. UTC
Add reproducer for a bug on ubifs where listxattr() copies
the newly created xattr names regardless of the remaining
buffer size, fails the assertion of used buffer size,
and may corrupt buffer memory.

Signed-off-by: Hou Tao <houtao1@huawei.com>
---
v2: accommodate f2fs by reducing the number of created xattrs for f2fs

 tests/generic/998     | 67 +++++++++++++++++++++++++++++++++++++++++++
 tests/generic/998.out |  2 ++
 tests/generic/group   |  1 +
 3 files changed, 70 insertions(+)
 create mode 100644 tests/generic/998
 create mode 100644 tests/generic/998.out

Comments

Eryu Guan Aug. 30, 2020, 4:23 p.m. UTC | #1
On Sat, Aug 22, 2020 at 07:41:32PM +0800, Hou Tao wrote:
> Add reproducer for a bug on ubifs where listxattr() copies
> the newly created xattr names regardless of the remaining
> buffer size, fails the assertion of used buffer size,
> and may corrupt buffer memory.
> 
> Signed-off-by: Hou Tao <houtao1@huawei.com>
> ---
> v2: accommodate f2fs by reducing the number of created xattrs for f2fs

Thanks for the test and revision! Is there a fix available for the ubifs
bug? If so would you please mention the kernel commit ID in commit log
as well?

Chao, would you please help check the update regarding to f2fs? Thanks!

Eryu

> 
>  tests/generic/998     | 67 +++++++++++++++++++++++++++++++++++++++++++
>  tests/generic/998.out |  2 ++
>  tests/generic/group   |  1 +
>  3 files changed, 70 insertions(+)
>  create mode 100644 tests/generic/998
>  create mode 100644 tests/generic/998.out
> 
> diff --git a/tests/generic/998 b/tests/generic/998
> new file mode 100644
> index 00000000..26a5b620
> --- /dev/null
> +++ b/tests/generic/998
> @@ -0,0 +1,67 @@
> +#! /bin/bash
> +# SPDX-License-Identifier: GPL-2.0
> +# Copyright (c) 2020 Huawei. All Rights Reserved.
> +#
> +# FS QA Test 998
> +#
> +# Test race between listxattr() and setxattr(). It reproduces a bug
> +# on UBIFS where listxattr() copies the newly created xattr names
> +# regardless of the remaining buffer size, fails the assertion of
> +# used buffer size, and may corrupt buffer memory.
> +#
> +seq=`basename $0`
> +seqres=$RESULT_DIR/$seq
> +echo "QA output created by $seq"
> +
> +here=`pwd`
> +tmp=/tmp/$$
> +status=1	# failure is the default!
> +trap "_cleanup; exit \$status" 0 1 2 3 15
> +
> +_cleanup()
> +{
> +	cd /
> +	rm -f $tmp.*
> +	rm -f $TEST_DIR/$seq
> +}
> +
> +# get standard environment, filters and checks
> +. ./common/rc
> +. ./common/attr
> +
> +# remove previous $seqres.full before test
> +rm -f $seqres.full
> +
> +# real QA test starts here
> +_supported_fs generic
> +_supported_os Linux
> +_require_attrs
> +
> +target=$TEST_DIR/$seq
> +touch $target
> +
> +# start a background listxattr
> +runfile="$tmp.listxattr"
> +touch $runfile
> +while [ -e $runfile ]; do
> +	${GETFATTR_PROG} $target >/dev/null 2>&1
> +done &
> +
> +# add new xattr continuously
> +largename=`for i in $(seq 0 128); do echo -n a; done`
> +cnt=100
> +# f2fs has limited spaces for xattr
> +[ $FSTYP == "f2fs" ] && cnt=30
> +for i in $(seq 1 $cnt); do
> +	${SETFATTR_PROG} -n user.${largename}.$i -v $i $target
> +done
> +
> +rm -f $runfile
> +wait > /dev/null 2>&1
> +rm -f $target
> +
> +echo Silence is golden
> +
> +# success, all done
> +status=0
> +exit
> diff --git a/tests/generic/998.out b/tests/generic/998.out
> new file mode 100644
> index 00000000..d2679ae0
> --- /dev/null
> +++ b/tests/generic/998.out
> @@ -0,0 +1,2 @@
> +QA output created by 998
> +Silence is golden
> diff --git a/tests/generic/group b/tests/generic/group
> index d9ab9a31..62697ac5 100644
> --- a/tests/generic/group
> +++ b/tests/generic/group
> @@ -605,3 +605,4 @@
>  600 auto quick quota
>  601 auto quick quota
>  602 auto quick encrypt
> +998 auto quick attr
> -- 
> 2.25.0.4.g0ad7144999
Chao Yu Aug. 31, 2020, 1:19 a.m. UTC | #2
On 2020/8/31 0:23, Eryu Guan wrote:
> On Sat, Aug 22, 2020 at 07:41:32PM +0800, Hou Tao wrote:
>> Add reproducer for a bug on ubifs where listxattr() copies
>> the newly created xattr names regardless of the remaining
>> buffer size, fails the assertion of used buffer size,
>> and may corrupt buffer memory.
>>
>> Signed-off-by: Hou Tao <houtao1@huawei.com>
>> ---
>> v2: accommodate f2fs by reducing the number of created xattrs for f2fs
> 
> Thanks for the test and revision! Is there a fix available for the ubifs
> bug? If so would you please mention the kernel commit ID in commit log
> as well?
> 
> Chao, would you please help check the update regarding to f2fs? Thanks!

Hi, all,

Sorry for the delay.

I've ran the test, it looks fine to f2fs, and also parameter value 'cnt=30'
is just touch upper boundary of xattr space size. :)

Reviewed-by: Chao Yu <yuchao0@huawei.com>

Thanks,

> 
> Eryu
> 
>>
>>   tests/generic/998     | 67 +++++++++++++++++++++++++++++++++++++++++++
>>   tests/generic/998.out |  2 ++
>>   tests/generic/group   |  1 +
>>   3 files changed, 70 insertions(+)
>>   create mode 100644 tests/generic/998
>>   create mode 100644 tests/generic/998.out
>>
>> diff --git a/tests/generic/998 b/tests/generic/998
>> new file mode 100644
>> index 00000000..26a5b620
>> --- /dev/null
>> +++ b/tests/generic/998
>> @@ -0,0 +1,67 @@
>> +#! /bin/bash
>> +# SPDX-License-Identifier: GPL-2.0
>> +# Copyright (c) 2020 Huawei. All Rights Reserved.
>> +#
>> +# FS QA Test 998
>> +#
>> +# Test race between listxattr() and setxattr(). It reproduces a bug
>> +# on UBIFS where listxattr() copies the newly created xattr names
>> +# regardless of the remaining buffer size, fails the assertion of
>> +# used buffer size, and may corrupt buffer memory.
>> +#
>> +seq=`basename $0`
>> +seqres=$RESULT_DIR/$seq
>> +echo "QA output created by $seq"
>> +
>> +here=`pwd`
>> +tmp=/tmp/$$
>> +status=1	# failure is the default!
>> +trap "_cleanup; exit \$status" 0 1 2 3 15
>> +
>> +_cleanup()
>> +{
>> +	cd /
>> +	rm -f $tmp.*
>> +	rm -f $TEST_DIR/$seq
>> +}
>> +
>> +# get standard environment, filters and checks
>> +. ./common/rc
>> +. ./common/attr
>> +
>> +# remove previous $seqres.full before test
>> +rm -f $seqres.full
>> +
>> +# real QA test starts here
>> +_supported_fs generic
>> +_supported_os Linux
>> +_require_attrs
>> +
>> +target=$TEST_DIR/$seq
>> +touch $target
>> +
>> +# start a background listxattr
>> +runfile="$tmp.listxattr"
>> +touch $runfile
>> +while [ -e $runfile ]; do
>> +	${GETFATTR_PROG} $target >/dev/null 2>&1
>> +done &
>> +
>> +# add new xattr continuously
>> +largename=`for i in $(seq 0 128); do echo -n a; done`
>> +cnt=100
>> +# f2fs has limited spaces for xattr
>> +[ $FSTYP == "f2fs" ] && cnt=30
>> +for i in $(seq 1 $cnt); do
>> +	${SETFATTR_PROG} -n user.${largename}.$i -v $i $target
>> +done
>> +
>> +rm -f $runfile
>> +wait > /dev/null 2>&1
>> +rm -f $target
>> +
>> +echo Silence is golden
>> +
>> +# success, all done
>> +status=0
>> +exit
>> diff --git a/tests/generic/998.out b/tests/generic/998.out
>> new file mode 100644
>> index 00000000..d2679ae0
>> --- /dev/null
>> +++ b/tests/generic/998.out
>> @@ -0,0 +1,2 @@
>> +QA output created by 998
>> +Silence is golden
>> diff --git a/tests/generic/group b/tests/generic/group
>> index d9ab9a31..62697ac5 100644
>> --- a/tests/generic/group
>> +++ b/tests/generic/group
>> @@ -605,3 +605,4 @@
>>   600 auto quick quota
>>   601 auto quick quota
>>   602 auto quick encrypt
>> +998 auto quick attr
>> -- 
>> 2.25.0.4.g0ad7144999
> .
>
Hou Tao Aug. 31, 2020, 3:01 a.m. UTC | #3
Hi,

On 2020/8/31 0:23, Eryu Guan wrote:
> On Sat, Aug 22, 2020 at 07:41:32PM +0800, Hou Tao wrote:
>> Add reproducer for a bug on ubifs where listxattr() copies
>> the newly created xattr names regardless of the remaining
>> buffer size, fails the assertion of used buffer size,
>> and may corrupt buffer memory.
>>
>> Signed-off-by: Hou Tao <houtao1@huawei.com>
>> ---
>> v2: accommodate f2fs by reducing the number of created xattrs for f2fs
> 
> Thanks for the test and revision! Is there a fix available for the ubifs
> bug? If so would you please mention the kernel commit ID in commit log
> as well?
> 
The fixes [1] have not been reviewed yet, so we may need to hold on until the fixes get merged ?

[1]: https://lore.kernel.org/linux-mtd/20200630130438.141649-1-houtao1@huawei.com/

Regards,
Tao

> Chao, would you please help check the update regarding to f2fs? Thanks!
> 
> Eryu
> 
>>
>>  tests/generic/998     | 67 +++++++++++++++++++++++++++++++++++++++++++
>>  tests/generic/998.out |  2 ++
>>  tests/generic/group   |  1 +
>>  3 files changed, 70 insertions(+)
>>  create mode 100644 tests/generic/998
>>  create mode 100644 tests/generic/998.out
>>
>> diff --git a/tests/generic/998 b/tests/generic/998
>> new file mode 100644
>> index 00000000..26a5b620
>> --- /dev/null
>> +++ b/tests/generic/998
>> @@ -0,0 +1,67 @@
>> +#! /bin/bash
>> +# SPDX-License-Identifier: GPL-2.0
>> +# Copyright (c) 2020 Huawei. All Rights Reserved.
>> +#
>> +# FS QA Test 998
>> +#
>> +# Test race between listxattr() and setxattr(). It reproduces a bug
>> +# on UBIFS where listxattr() copies the newly created xattr names
>> +# regardless of the remaining buffer size, fails the assertion of
>> +# used buffer size, and may corrupt buffer memory.
>> +#
>> +seq=`basename $0`
>> +seqres=$RESULT_DIR/$seq
>> +echo "QA output created by $seq"
>> +
>> +here=`pwd`
>> +tmp=/tmp/$$
>> +status=1	# failure is the default!
>> +trap "_cleanup; exit \$status" 0 1 2 3 15
>> +
>> +_cleanup()
>> +{
>> +	cd /
>> +	rm -f $tmp.*
>> +	rm -f $TEST_DIR/$seq
>> +}
>> +
>> +# get standard environment, filters and checks
>> +. ./common/rc
>> +. ./common/attr
>> +
>> +# remove previous $seqres.full before test
>> +rm -f $seqres.full
>> +
>> +# real QA test starts here
>> +_supported_fs generic
>> +_supported_os Linux
>> +_require_attrs
>> +
>> +target=$TEST_DIR/$seq
>> +touch $target
>> +
>> +# start a background listxattr
>> +runfile="$tmp.listxattr"
>> +touch $runfile
>> +while [ -e $runfile ]; do
>> +	${GETFATTR_PROG} $target >/dev/null 2>&1
>> +done &
>> +
>> +# add new xattr continuously
>> +largename=`for i in $(seq 0 128); do echo -n a; done`
>> +cnt=100
>> +# f2fs has limited spaces for xattr
>> +[ $FSTYP == "f2fs" ] && cnt=30
>> +for i in $(seq 1 $cnt); do
>> +	${SETFATTR_PROG} -n user.${largename}.$i -v $i $target
>> +done
>> +
>> +rm -f $runfile
>> +wait > /dev/null 2>&1
>> +rm -f $target
>> +
>> +echo Silence is golden
>> +
>> +# success, all done
>> +status=0
>> +exit
>> diff --git a/tests/generic/998.out b/tests/generic/998.out
>> new file mode 100644
>> index 00000000..d2679ae0
>> --- /dev/null
>> +++ b/tests/generic/998.out
>> @@ -0,0 +1,2 @@
>> +QA output created by 998
>> +Silence is golden
>> diff --git a/tests/generic/group b/tests/generic/group
>> index d9ab9a31..62697ac5 100644
>> --- a/tests/generic/group
>> +++ b/tests/generic/group
>> @@ -605,3 +605,4 @@
>>  600 auto quick quota
>>  601 auto quick quota
>>  602 auto quick encrypt
>> +998 auto quick attr
>> -- 
>> 2.25.0.4.g0ad7144999
> .
>
Eryu Guan Sept. 2, 2020, 3:48 p.m. UTC | #4
On Mon, Aug 31, 2020 at 11:01:05AM +0800, Hou Tao wrote:
> Hi,
> 
> On 2020/8/31 0:23, Eryu Guan wrote:
> > On Sat, Aug 22, 2020 at 07:41:32PM +0800, Hou Tao wrote:
> >> Add reproducer for a bug on ubifs where listxattr() copies
> >> the newly created xattr names regardless of the remaining
> >> buffer size, fails the assertion of used buffer size,
> >> and may corrupt buffer memory.
> >>
> >> Signed-off-by: Hou Tao <houtao1@huawei.com>
> >> ---
> >> v2: accommodate f2fs by reducing the number of created xattrs for f2fs
> > 
> > Thanks for the test and revision! Is there a fix available for the ubifs
> > bug? If so would you please mention the kernel commit ID in commit log
> > as well?
> > 
> The fixes [1] have not been reviewed yet, so we may need to hold on until the fixes get merged ?
> 
> [1]: https://lore.kernel.org/linux-mtd/20200630130438.141649-1-houtao1@huawei.com/

It's better to have the fixes merged first, but we do merge tests before
the fixes landed in. But I'd like to see at least some reviews/acks on
the fixes first.

Thanks,
Eryu
Darrick J. Wong Sept. 2, 2020, 4:43 p.m. UTC | #5
On Sat, Aug 22, 2020 at 07:41:32PM +0800, Hou Tao wrote:
> Add reproducer for a bug on ubifs where listxattr() copies
> the newly created xattr names regardless of the remaining
> buffer size, fails the assertion of used buffer size,
> and may corrupt buffer memory.
> 
> Signed-off-by: Hou Tao <houtao1@huawei.com>
> ---
> v2: accommodate f2fs by reducing the number of created xattrs for f2fs
> 
>  tests/generic/998     | 67 +++++++++++++++++++++++++++++++++++++++++++
>  tests/generic/998.out |  2 ++
>  tests/generic/group   |  1 +
>  3 files changed, 70 insertions(+)
>  create mode 100644 tests/generic/998
>  create mode 100644 tests/generic/998.out
> 
> diff --git a/tests/generic/998 b/tests/generic/998
> new file mode 100644
> index 00000000..26a5b620
> --- /dev/null
> +++ b/tests/generic/998
> @@ -0,0 +1,67 @@
> +#! /bin/bash
> +# SPDX-License-Identifier: GPL-2.0
> +# Copyright (c) 2020 Huawei. All Rights Reserved.
> +#
> +# FS QA Test 998
> +#
> +# Test race between listxattr() and setxattr(). It reproduces a bug
> +# on UBIFS where listxattr() copies the newly created xattr names
> +# regardless of the remaining buffer size, fails the assertion of
> +# used buffer size, and may corrupt buffer memory.
> +#
> +seq=`basename $0`
> +seqres=$RESULT_DIR/$seq
> +echo "QA output created by $seq"
> +
> +here=`pwd`
> +tmp=/tmp/$$
> +status=1	# failure is the default!
> +trap "_cleanup; exit \$status" 0 1 2 3 15
> +
> +_cleanup()
> +{
> +	cd /
> +	rm -f $tmp.*
> +	rm -f $TEST_DIR/$seq
> +}
> +
> +# get standard environment, filters and checks
> +. ./common/rc
> +. ./common/attr
> +
> +# remove previous $seqres.full before test
> +rm -f $seqres.full
> +
> +# real QA test starts here
> +_supported_fs generic
> +_supported_os Linux
> +_require_attrs
> +
> +target=$TEST_DIR/$seq
> +touch $target
> +
> +# start a background listxattr
> +runfile="$tmp.listxattr"
> +touch $runfile
> +while [ -e $runfile ]; do
> +	${GETFATTR_PROG} $target >/dev/null 2>&1

Er, if the listxattr corrupts the buffer memory, how does this test
detect that?  Does the kernel crash or something?

> +done &
> +
> +# add new xattr continuously
> +largename=`for i in $(seq 0 128); do echo -n a; done`
> +cnt=100
> +# f2fs has limited spaces for xattr
> +[ $FSTYP == "f2fs" ] && cnt=30
> +for i in $(seq 1 $cnt); do
> +	${SETFATTR_PROG} -n user.${largename}.$i -v $i $target

Seeing as each filesystem has different xattr limits, I wonder if
instead of special casing of f2fs we ought to capture the
stdout/stderr of SETFATTR_PROG and filter out the ENOSPC message?

AFAICT this test isn't trying to check that setting xattrs succeeds, but
I'm a little confused on how we detect the corrupted buffer...

--D

> +done
> +
> +rm -f $runfile
> +wait > /dev/null 2>&1
> +rm -f $target
> +
> +echo Silence is golden
> +
> +# success, all done
> +status=0
> +exit
> diff --git a/tests/generic/998.out b/tests/generic/998.out
> new file mode 100644
> index 00000000..d2679ae0
> --- /dev/null
> +++ b/tests/generic/998.out
> @@ -0,0 +1,2 @@
> +QA output created by 998
> +Silence is golden
> diff --git a/tests/generic/group b/tests/generic/group
> index d9ab9a31..62697ac5 100644
> --- a/tests/generic/group
> +++ b/tests/generic/group
> @@ -605,3 +605,4 @@
>  600 auto quick quota
>  601 auto quick quota
>  602 auto quick encrypt
> +998 auto quick attr
> -- 
> 2.25.0.4.g0ad7144999
>
diff mbox series

Patch

diff --git a/tests/generic/998 b/tests/generic/998
new file mode 100644
index 00000000..26a5b620
--- /dev/null
+++ b/tests/generic/998
@@ -0,0 +1,67 @@ 
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (c) 2020 Huawei. All Rights Reserved.
+#
+# FS QA Test 998
+#
+# Test race between listxattr() and setxattr(). It reproduces a bug
+# on UBIFS where listxattr() copies the newly created xattr names
+# regardless of the remaining buffer size, fails the assertion of
+# used buffer size, and may corrupt buffer memory.
+#
+seq=`basename $0`
+seqres=$RESULT_DIR/$seq
+echo "QA output created by $seq"
+
+here=`pwd`
+tmp=/tmp/$$
+status=1	# failure is the default!
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+_cleanup()
+{
+	cd /
+	rm -f $tmp.*
+	rm -f $TEST_DIR/$seq
+}
+
+# get standard environment, filters and checks
+. ./common/rc
+. ./common/attr
+
+# remove previous $seqres.full before test
+rm -f $seqres.full
+
+# real QA test starts here
+_supported_fs generic
+_supported_os Linux
+_require_attrs
+
+target=$TEST_DIR/$seq
+touch $target
+
+# start a background listxattr
+runfile="$tmp.listxattr"
+touch $runfile
+while [ -e $runfile ]; do
+	${GETFATTR_PROG} $target >/dev/null 2>&1
+done &
+
+# add new xattr continuously
+largename=`for i in $(seq 0 128); do echo -n a; done`
+cnt=100
+# f2fs has limited spaces for xattr
+[ $FSTYP == "f2fs" ] && cnt=30
+for i in $(seq 1 $cnt); do
+	${SETFATTR_PROG} -n user.${largename}.$i -v $i $target
+done
+
+rm -f $runfile
+wait > /dev/null 2>&1
+rm -f $target
+
+echo Silence is golden
+
+# success, all done
+status=0
+exit
diff --git a/tests/generic/998.out b/tests/generic/998.out
new file mode 100644
index 00000000..d2679ae0
--- /dev/null
+++ b/tests/generic/998.out
@@ -0,0 +1,2 @@ 
+QA output created by 998
+Silence is golden
diff --git a/tests/generic/group b/tests/generic/group
index d9ab9a31..62697ac5 100644
--- a/tests/generic/group
+++ b/tests/generic/group
@@ -605,3 +605,4 @@ 
 600 auto quick quota
 601 auto quick quota
 602 auto quick encrypt
+998 auto quick attr