<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/net/core/ethtool.c, branch v4.19.321</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>net/ethtool/ioctl: return -EOPNOTSUPP if we have no phy stats</title>
<updated>2023-01-24T06:11:49+00:00</updated>
<author>
<name>Daniil Tatianin</name>
<email>d-tatianin@yandex-team.ru</email>
</author>
<published>2022-12-26T11:48:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=2cf8dd47089fed40b263fb26be58e4e4da28a8a8'/>
<id>2cf8dd47089fed40b263fb26be58e4e4da28a8a8</id>
<content type='text'>
[ Upstream commit 9deb1e9fb88b1120a908676fa33bdf9e2eeaefce ]

It's not very useful to copy back an empty ethtool_stats struct and
return 0 if we didn't actually have any stats. This also allows for
further simplification of this function in the future commits.

Signed-off-by: Daniil Tatianin &lt;d-tatianin@yandex-team.ru&gt;
Reviewed-by: Andrew Lunn &lt;andrew@lunn.ch&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 9deb1e9fb88b1120a908676fa33bdf9e2eeaefce ]

It's not very useful to copy back an empty ethtool_stats struct and
return 0 if we didn't actually have any stats. This also allows for
further simplification of this function in the future commits.

Signed-off-by: Daniil Tatianin &lt;d-tatianin@yandex-team.ru&gt;
Reviewed-by: Andrew Lunn &lt;andrew@lunn.ch&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: ethtool: clear heap allocations for ethtool function</title>
<updated>2021-06-30T12:48:30+00:00</updated>
<author>
<name>Austin Kim</name>
<email>austindh.kim@gmail.com</email>
</author>
<published>2021-06-09T02:34:25+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=8b0f8cf5b02df6447974eea1a456b9f642fa1241'/>
<id>8b0f8cf5b02df6447974eea1a456b9f642fa1241</id>
<content type='text'>
[ Upstream commit 80ec82e3d2c1fab42eeb730aaa7985494a963d3f ]

Several ethtool functions leave heap uncleared (potentially) by
drivers. This will leave the unused portion of heap unchanged and
might copy the full contents back to userspace.

Signed-off-by: Austin Kim &lt;austindh.kim@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 80ec82e3d2c1fab42eeb730aaa7985494a963d3f ]

Several ethtool functions leave heap uncleared (potentially) by
drivers. This will leave the unused portion of heap unchanged and
might copy the full contents back to userspace.

Signed-off-by: Austin Kim &lt;austindh.kim@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ethtool: ioctl: Fix out-of-bounds warning in store_link_ksettings_for_user()</title>
<updated>2021-05-22T08:59:41+00:00</updated>
<author>
<name>Gustavo A. R. Silva</name>
<email>gustavoars@kernel.org</email>
</author>
<published>2021-04-16T20:15:40+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b1352870018fa0cff265ff1357434195e8481560'/>
<id>b1352870018fa0cff265ff1357434195e8481560</id>
<content type='text'>
[ Upstream commit c1d9e34e11281a8ba1a1c54e4db554232a461488 ]

Fix the following out-of-bounds warning:

net/ethtool/ioctl.c:492:2: warning: 'memcpy' offset [49, 84] from the object at 'link_usettings' is out of the bounds of referenced subobject 'base' with type 'struct ethtool_link_settings' at offset 0 [-Warray-bounds]

The problem is that the original code is trying to copy data into a
some struct members adjacent to each other in a single call to
memcpy(). This causes a legitimate compiler warning because memcpy()
overruns the length of &amp;link_usettings.base. Fix this by directly
using &amp;link_usettings and _from_ as destination and source addresses,
instead.

This helps with the ongoing efforts to globally enable -Warray-bounds
and get us closer to being able to tighten the FORTIFY_SOURCE routines
on memcpy().

Link: https://github.com/KSPP/linux/issues/109
Reported-by: kernel test robot &lt;lkp@intel.com&gt;
Signed-off-by: Gustavo A. R. Silva &lt;gustavoars@kernel.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit c1d9e34e11281a8ba1a1c54e4db554232a461488 ]

Fix the following out-of-bounds warning:

net/ethtool/ioctl.c:492:2: warning: 'memcpy' offset [49, 84] from the object at 'link_usettings' is out of the bounds of referenced subobject 'base' with type 'struct ethtool_link_settings' at offset 0 [-Warray-bounds]

The problem is that the original code is trying to copy data into a
some struct members adjacent to each other in a single call to
memcpy(). This causes a legitimate compiler warning because memcpy()
overruns the length of &amp;link_usettings.base. Fix this by directly
using &amp;link_usettings and _from_ as destination and source addresses,
instead.

This helps with the ongoing efforts to globally enable -Warray-bounds
and get us closer to being able to tighten the FORTIFY_SOURCE routines
on memcpy().

Link: https://github.com/KSPP/linux/issues/109
Reported-by: kernel test robot &lt;lkp@intel.com&gt;
Signed-off-by: Gustavo A. R. Silva &lt;gustavoars@kernel.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ethtool: reduce stack usage with clang</title>
<updated>2020-01-17T18:46:55+00:00</updated>
<author>
<name>Arnd Bergmann</name>
<email>arnd@arndb.de</email>
</author>
<published>2019-03-07T15:58:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=81f7503fb41bf734bfc7ce2d38bb537d3c15214b'/>
<id>81f7503fb41bf734bfc7ce2d38bb537d3c15214b</id>
<content type='text'>
commit 3499e87ea0413ee5b2cc028f4c8ed4d424bc7f98 upstream.

clang inlines the dev_ethtool() more aggressively than gcc does, leading
to a larger amount of used stack space:

net/core/ethtool.c:2536:24: error: stack frame size of 1216 bytes in function 'dev_ethtool' [-Werror,-Wframe-larger-than=]

Marking the sub-functions that require the most stack space as
noinline_for_stack gives us reasonable behavior on all compilers.

Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Reviewed-by: Michal Kubecek &lt;mkubecek@suse.cz&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Miles Chen &lt;miles.chen@mediatek.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 3499e87ea0413ee5b2cc028f4c8ed4d424bc7f98 upstream.

clang inlines the dev_ethtool() more aggressively than gcc does, leading
to a larger amount of used stack space:

net/core/ethtool.c:2536:24: error: stack frame size of 1216 bytes in function 'dev_ethtool' [-Werror,-Wframe-larger-than=]

Marking the sub-functions that require the most stack space as
noinline_for_stack gives us reasonable behavior on all compilers.

Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Reviewed-by: Michal Kubecek &lt;mkubecek@suse.cz&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Miles Chen &lt;miles.chen@mediatek.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>net: Zeroing the structure ethtool_wolinfo in ethtool_get_wol()</title>
<updated>2019-11-10T10:27:44+00:00</updated>
<author>
<name>zhanglin</name>
<email>zhang.lin16@zte.com.cn</email>
</author>
<published>2019-10-26T07:54:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=321c99155f4b4d29a77f2a9a30593fc0b222a305'/>
<id>321c99155f4b4d29a77f2a9a30593fc0b222a305</id>
<content type='text'>
[ Upstream commit 5ff223e86f5addbfae26419cbb5d61d98f6fbf7d ]

memset() the structure ethtool_wolinfo that has padded bytes
but the padded bytes have not been zeroed out.

Signed-off-by: zhanglin &lt;zhang.lin16@zte.com.cn&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 5ff223e86f5addbfae26419cbb5d61d98f6fbf7d ]

memset() the structure ethtool_wolinfo that has padded bytes
but the padded bytes have not been zeroed out.

Signed-off-by: zhanglin &lt;zhang.lin16@zte.com.cn&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ethtool: check the return value of get_regs_len</title>
<updated>2019-06-11T10:20:57+00:00</updated>
<author>
<name>Yunsheng Lin</name>
<email>linyunsheng@huawei.com</email>
</author>
<published>2018-12-26T11:51:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=51dc284e2a87352f7339d721c47f8648d7bc4a79'/>
<id>51dc284e2a87352f7339d721c47f8648d7bc4a79</id>
<content type='text'>
commit f9fc54d313fab2834f44f516459cdc8ac91d797f upstream.

The return type for get_regs_len in struct ethtool_ops is int,
the hns3 driver may return error when failing to get the regs
len by sending cmd to firmware.

Signed-off-by: Yunsheng Lin &lt;linyunsheng@huawei.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Cc: Michal Kubecek &lt;mkubecek@suse.cz&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit f9fc54d313fab2834f44f516459cdc8ac91d797f upstream.

The return type for get_regs_len in struct ethtool_ops is int,
the hns3 driver may return error when failing to get the regs
len by sending cmd to firmware.

Signed-off-by: Yunsheng Lin &lt;linyunsheng@huawei.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Cc: Michal Kubecek &lt;mkubecek@suse.cz&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>ethtool: fix potential userspace buffer overflow</title>
<updated>2019-06-11T10:20:47+00:00</updated>
<author>
<name>Vivien Didelot</name>
<email>vivien.didelot@gmail.com</email>
</author>
<published>2019-06-03T20:57:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d6782b8c5c1831f65eead98b5b7c41bbf2dd20df'/>
<id>d6782b8c5c1831f65eead98b5b7c41bbf2dd20df</id>
<content type='text'>
[ Upstream commit 0ee4e76937d69128a6a66861ba393ebdc2ffc8a2 ]

ethtool_get_regs() allocates a buffer of size ops-&gt;get_regs_len(),
and pass it to the kernel driver via ops-&gt;get_regs() for filling.

There is no restriction about what the kernel drivers can or cannot do
with the open ethtool_regs structure. They usually set regs-&gt;version
and ignore regs-&gt;len or set it to the same size as ops-&gt;get_regs_len().

But if userspace allocates a smaller buffer for the registers dump,
we would cause a userspace buffer overflow in the final copy_to_user()
call, which uses the regs.len value potentially reset by the driver.

To fix this, make this case obvious and store regs.len before calling
ops-&gt;get_regs(), to only copy as much data as requested by userspace,
up to the value returned by ops-&gt;get_regs_len().

While at it, remove the redundant check for non-null regbuf.

Signed-off-by: Vivien Didelot &lt;vivien.didelot@gmail.com&gt;
Reviewed-by: Michal Kubecek &lt;mkubecek@suse.cz&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 0ee4e76937d69128a6a66861ba393ebdc2ffc8a2 ]

ethtool_get_regs() allocates a buffer of size ops-&gt;get_regs_len(),
and pass it to the kernel driver via ops-&gt;get_regs() for filling.

There is no restriction about what the kernel drivers can or cannot do
with the open ethtool_regs structure. They usually set regs-&gt;version
and ignore regs-&gt;len or set it to the same size as ops-&gt;get_regs_len().

But if userspace allocates a smaller buffer for the registers dump,
we would cause a userspace buffer overflow in the final copy_to_user()
call, which uses the regs.len value potentially reset by the driver.

To fix this, make this case obvious and store regs.len before calling
ops-&gt;get_regs(), to only copy as much data as requested by userspace,
up to the value returned by ops-&gt;get_regs_len().

While at it, remove the redundant check for non-null regbuf.

Signed-off-by: Vivien Didelot &lt;vivien.didelot@gmail.com&gt;
Reviewed-by: Michal Kubecek &lt;mkubecek@suse.cz&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: ethtool: not call vzalloc for zero sized memory request</title>
<updated>2019-04-17T06:38:40+00:00</updated>
<author>
<name>Li RongQing</name>
<email>lirongqing@baidu.com</email>
</author>
<published>2019-03-29T01:18:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=80c205813d3f5d7a912c73487d1ee6d76a696af1'/>
<id>80c205813d3f5d7a912c73487d1ee6d76a696af1</id>
<content type='text'>
[ Upstream commit 3d8830266ffc28c16032b859e38a0252e014b631 ]

NULL or ZERO_SIZE_PTR will be returned for zero sized memory
request, and derefencing them will lead to a segfault

so it is unnecessory to call vzalloc for zero sized memory
request and not call functions which maybe derefence the
NULL allocated memory

this also fixes a possible memory leak if phy_ethtool_get_stats
returns error, memory should be freed before exit

Signed-off-by: Li RongQing &lt;lirongqing@baidu.com&gt;
Reviewed-by: Wang Li &lt;wangli39@baidu.com&gt;
Reviewed-by: Michal Kubecek &lt;mkubecek@suse.cz&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 3d8830266ffc28c16032b859e38a0252e014b631 ]

NULL or ZERO_SIZE_PTR will be returned for zero sized memory
request, and derefencing them will lead to a segfault

so it is unnecessory to call vzalloc for zero sized memory
request and not call functions which maybe derefence the
NULL allocated memory

this also fixes a possible memory leak if phy_ethtool_get_stats
returns error, memory should be freed before exit

Signed-off-by: Li RongQing &lt;lirongqing@baidu.com&gt;
Reviewed-by: Wang Li &lt;wangli39@baidu.com&gt;
Reviewed-by: Michal Kubecek &lt;mkubecek@suse.cz&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ethtool: fix a privilege escalation bug</title>
<updated>2018-10-16T04:37:58+00:00</updated>
<author>
<name>Wenwen Wang</name>
<email>wang6495@umn.edu</email>
</author>
<published>2018-10-08T15:49:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=58f5bbe331c566f49c9559568f982202a278aa78'/>
<id>58f5bbe331c566f49c9559568f982202a278aa78</id>
<content type='text'>
In dev_ethtool(), the eth command 'ethcmd' is firstly copied from the
use-space buffer 'useraddr' and checked to see whether it is
ETHTOOL_PERQUEUE. If yes, the sub-command 'sub_cmd' is further copied from
the user space. Otherwise, 'sub_cmd' is the same as 'ethcmd'. Next,
according to 'sub_cmd', a permission check is enforced through the function
ns_capable(). For example, the permission check is required if 'sub_cmd' is
ETHTOOL_SCOALESCE, but it is not necessary if 'sub_cmd' is
ETHTOOL_GCOALESCE, as suggested in the comment "Allow some commands to be
done by anyone". The following execution invokes different handlers
according to 'ethcmd'. Specifically, if 'ethcmd' is ETHTOOL_PERQUEUE,
ethtool_set_per_queue() is called. In ethtool_set_per_queue(), the kernel
object 'per_queue_opt' is copied again from the user-space buffer
'useraddr' and 'per_queue_opt.sub_command' is used to determine which
operation should be performed. Given that the buffer 'useraddr' is in the
user space, a malicious user can race to change the sub-command between the
two copies. In particular, the attacker can supply ETHTOOL_PERQUEUE and
ETHTOOL_GCOALESCE to bypass the permission check in dev_ethtool(). Then
before ethtool_set_per_queue() is called, the attacker changes
ETHTOOL_GCOALESCE to ETHTOOL_SCOALESCE. In this way, the attacker can
bypass the permission check and execute ETHTOOL_SCOALESCE.

This patch enforces a check in ethtool_set_per_queue() after the second
copy from 'useraddr'. If the sub-command is different from the one obtained
in the first copy in dev_ethtool(), an error code EINVAL will be returned.

Fixes: f38d138a7da6 ("net/ethtool: support set coalesce per queue")
Signed-off-by: Wenwen Wang &lt;wang6495@umn.edu&gt;
Reviewed-by: Michal Kubecek &lt;mkubecek@suse.cz&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
In dev_ethtool(), the eth command 'ethcmd' is firstly copied from the
use-space buffer 'useraddr' and checked to see whether it is
ETHTOOL_PERQUEUE. If yes, the sub-command 'sub_cmd' is further copied from
the user space. Otherwise, 'sub_cmd' is the same as 'ethcmd'. Next,
according to 'sub_cmd', a permission check is enforced through the function
ns_capable(). For example, the permission check is required if 'sub_cmd' is
ETHTOOL_SCOALESCE, but it is not necessary if 'sub_cmd' is
ETHTOOL_GCOALESCE, as suggested in the comment "Allow some commands to be
done by anyone". The following execution invokes different handlers
according to 'ethcmd'. Specifically, if 'ethcmd' is ETHTOOL_PERQUEUE,
ethtool_set_per_queue() is called. In ethtool_set_per_queue(), the kernel
object 'per_queue_opt' is copied again from the user-space buffer
'useraddr' and 'per_queue_opt.sub_command' is used to determine which
operation should be performed. Given that the buffer 'useraddr' is in the
user space, a malicious user can race to change the sub-command between the
two copies. In particular, the attacker can supply ETHTOOL_PERQUEUE and
ETHTOOL_GCOALESCE to bypass the permission check in dev_ethtool(). Then
before ethtool_set_per_queue() is called, the attacker changes
ETHTOOL_GCOALESCE to ETHTOOL_SCOALESCE. In this way, the attacker can
bypass the permission check and execute ETHTOOL_SCOALESCE.

This patch enforces a check in ethtool_set_per_queue() after the second
copy from 'useraddr'. If the sub-command is different from the one obtained
in the first copy in dev_ethtool(), an error code EINVAL will be returned.

Fixes: f38d138a7da6 ("net/ethtool: support set coalesce per queue")
Signed-off-by: Wenwen Wang &lt;wang6495@umn.edu&gt;
Reviewed-by: Michal Kubecek &lt;mkubecek@suse.cz&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ethtool: fix a missing-check bug</title>
<updated>2018-10-16T04:37:01+00:00</updated>
<author>
<name>Wenwen Wang</name>
<email>wang6495@umn.edu</email>
</author>
<published>2018-10-09T13:15:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=2bb3207dbbd4d30e96dd0e1c8e013104193bd59c'/>
<id>2bb3207dbbd4d30e96dd0e1c8e013104193bd59c</id>
<content type='text'>
In ethtool_get_rxnfc(), the eth command 'cmd' is compared against
'ETHTOOL_GRXFH' to see whether it is necessary to adjust the variable
'info_size'. Then the whole structure of 'info' is copied from the
user-space buffer 'useraddr' with 'info_size' bytes. In the following
execution, 'info' may be copied again from the buffer 'useraddr' depending
on the 'cmd' and the 'info.flow_type'. However, after these two copies,
there is no check between 'cmd' and 'info.cmd'. In fact, 'cmd' is also
copied from the buffer 'useraddr' in dev_ethtool(), which is the caller
function of ethtool_get_rxnfc(). Given that 'useraddr' is in the user
space, a malicious user can race to change the eth command in the buffer
between these copies. By doing so, the attacker can supply inconsistent
data and cause undefined behavior because in the following execution 'info'
will be passed to ops-&gt;get_rxnfc().

This patch adds a necessary check on 'info.cmd' and 'cmd' to confirm that
they are still same after the two copies in ethtool_get_rxnfc(). Otherwise,
an error code EINVAL will be returned.

Signed-off-by: Wenwen Wang &lt;wang6495@umn.edu&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
In ethtool_get_rxnfc(), the eth command 'cmd' is compared against
'ETHTOOL_GRXFH' to see whether it is necessary to adjust the variable
'info_size'. Then the whole structure of 'info' is copied from the
user-space buffer 'useraddr' with 'info_size' bytes. In the following
execution, 'info' may be copied again from the buffer 'useraddr' depending
on the 'cmd' and the 'info.flow_type'. However, after these two copies,
there is no check between 'cmd' and 'info.cmd'. In fact, 'cmd' is also
copied from the buffer 'useraddr' in dev_ethtool(), which is the caller
function of ethtool_get_rxnfc(). Given that 'useraddr' is in the user
space, a malicious user can race to change the eth command in the buffer
between these copies. By doing so, the attacker can supply inconsistent
data and cause undefined behavior because in the following execution 'info'
will be passed to ops-&gt;get_rxnfc().

This patch adds a necessary check on 'info.cmd' and 'cmd' to confirm that
they are still same after the two copies in ethtool_get_rxnfc(). Otherwise,
an error code EINVAL will be returned.

Signed-off-by: Wenwen Wang &lt;wang6495@umn.edu&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
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