<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git, branch v5.4.264</title>
<subtitle>Clone of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git</subtitle>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/'/>
<entry>
<title>Linux 5.4.264</title>
<updated>2023-12-13T17:18:18+00:00</updated>
<author>
<name>Greg Kroah-Hartman</name>
<email>gregkh@linuxfoundation.org</email>
</author>
<published>2023-12-13T17:18:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=16e6e107a688046df37976fb6d7310e886c8115d'/>
<id>16e6e107a688046df37976fb6d7310e886c8115d</id>
<content type='text'>
Link: https://lore.kernel.org/r/20231211182015.049134368@linuxfoundation.org
Tested-by: Florian Fainelli &lt;florian.fainelli@broadcom.com&gt;
Tested-by: Harshit Mogalapalli &lt;harshit.m.mogalapalli@oracle.com&gt;
Tested-by: Shuah Khan &lt;skhan@linuxfoundation.org&gt;
Tested-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Tested-by: Linux Kernel Functional Testing &lt;lkft@linaro.org&gt;
Tested-by: Jon Hunter &lt;jonathanh@nvidia.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>
Link: https://lore.kernel.org/r/20231211182015.049134368@linuxfoundation.org
Tested-by: Florian Fainelli &lt;florian.fainelli@broadcom.com&gt;
Tested-by: Harshit Mogalapalli &lt;harshit.m.mogalapalli@oracle.com&gt;
Tested-by: Shuah Khan &lt;skhan@linuxfoundation.org&gt;
Tested-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Tested-by: Linux Kernel Functional Testing &lt;lkft@linaro.org&gt;
Tested-by: Jon Hunter &lt;jonathanh@nvidia.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>devcoredump: Send uevent once devcd is ready</title>
<updated>2023-12-13T17:18:18+00:00</updated>
<author>
<name>Mukesh Ojha</name>
<email>quic_mojha@quicinc.com</email>
</author>
<published>2023-11-17T14:49:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=06bcac5c51519566d45f9e21b85d56457e12fcc2'/>
<id>06bcac5c51519566d45f9e21b85d56457e12fcc2</id>
<content type='text'>
[ Upstream commit af54d778a03853801d681c98c0c2a6c316ef9ca7 ]

dev_coredumpm() creates a devcoredump device and adds it
to the core kernel framework which eventually end up
sending uevent to the user space and later creates a
symbolic link to the failed device. An application
running in userspace may be interested in this symbolic
link to get the name of the failed device.

In a issue scenario, once uevent sent to the user space
it start reading '/sys/class/devcoredump/devcdX/failing_device'
to get the actual name of the device which might not been
created and it is in its path of creation.

To fix this, suppress sending uevent till the failing device
symbolic link gets created and send uevent once symbolic
link is created successfully.

Fixes: 833c95456a70 ("device coredump: add new device coredump class")
Signed-off-by: Mukesh Ojha &lt;quic_mojha@quicinc.com&gt;
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/1700232572-25823-1-git-send-email-quic_mojha@quicinc.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&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 af54d778a03853801d681c98c0c2a6c316ef9ca7 ]

dev_coredumpm() creates a devcoredump device and adds it
to the core kernel framework which eventually end up
sending uevent to the user space and later creates a
symbolic link to the failed device. An application
running in userspace may be interested in this symbolic
link to get the name of the failed device.

In a issue scenario, once uevent sent to the user space
it start reading '/sys/class/devcoredump/devcdX/failing_device'
to get the actual name of the device which might not been
created and it is in its path of creation.

To fix this, suppress sending uevent till the failing device
symbolic link gets created and send uevent once symbolic
link is created successfully.

Fixes: 833c95456a70 ("device coredump: add new device coredump class")
Signed-off-by: Mukesh Ojha &lt;quic_mojha@quicinc.com&gt;
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/1700232572-25823-1-git-send-email-quic_mojha@quicinc.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>devcoredump : Serialize devcd_del work</title>
<updated>2023-12-13T17:18:18+00:00</updated>
<author>
<name>Mukesh Ojha</name>
<email>quic_mojha@quicinc.com</email>
</author>
<published>2022-09-13T12:50:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=c6a1282e530d6e34da292857ec4c230c3a289199'/>
<id>c6a1282e530d6e34da292857ec4c230c3a289199</id>
<content type='text'>
[ Upstream commit 01daccf748323dfc61112f474cf2ba81015446b0 ]

In following scenario(diagram), when one thread X running dev_coredumpm()
adds devcd device to the framework which sends uevent notification to
userspace and another thread Y reads this uevent and call to
devcd_data_write() which eventually try to delete the queued timer that
is not initialized/queued yet.

So, debug object reports some warning and in the meantime, timer is
initialized and queued from X path. and from Y path, it gets reinitialized
again and timer-&gt;entry.pprev=NULL and try_to_grab_pending() stucks.

To fix this, introduce mutex and a boolean flag to serialize the behaviour.

 	cpu0(X)			                cpu1(Y)

    dev_coredump() uevent sent to user space
    device_add()  ======================&gt; user space process Y reads the
                                          uevents writes to devcd fd
                                          which results into writes to

                                         devcd_data_write()
                                           mod_delayed_work()
                                             try_to_grab_pending()
                                               del_timer()
                                                 debug_assert_init()
   INIT_DELAYED_WORK()
   schedule_delayed_work()
                                                   debug_object_fixup()
                                                     timer_fixup_assert_init()
                                                       timer_setup()
                                                         do_init_timer()
                                                       /*
                                                        Above call reinitializes
                                                        the timer to
                                                        timer-&gt;entry.pprev=NULL
                                                        and this will be checked
                                                        later in timer_pending() call.
                                                       */
                                                 timer_pending()
                                                  !hlist_unhashed_lockless(&amp;timer-&gt;entry)
                                                    !h-&gt;pprev
                                                /*
                                                  del_timer() checks h-&gt;pprev and finds
                                                  it to be NULL due to which
                                                  try_to_grab_pending() stucks.
                                                */

Link: https://lore.kernel.org/lkml/2e1f81e2-428c-f11f-ce92-eb11048cb271@quicinc.com/
Signed-off-by: Mukesh Ojha &lt;quic_mojha@quicinc.com&gt;
Link: https://lore.kernel.org/r/1663073424-13663-1-git-send-email-quic_mojha@quicinc.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Stable-dep-of: af54d778a038 ("devcoredump: Send uevent once devcd is ready")
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 01daccf748323dfc61112f474cf2ba81015446b0 ]

In following scenario(diagram), when one thread X running dev_coredumpm()
adds devcd device to the framework which sends uevent notification to
userspace and another thread Y reads this uevent and call to
devcd_data_write() which eventually try to delete the queued timer that
is not initialized/queued yet.

So, debug object reports some warning and in the meantime, timer is
initialized and queued from X path. and from Y path, it gets reinitialized
again and timer-&gt;entry.pprev=NULL and try_to_grab_pending() stucks.

To fix this, introduce mutex and a boolean flag to serialize the behaviour.

 	cpu0(X)			                cpu1(Y)

    dev_coredump() uevent sent to user space
    device_add()  ======================&gt; user space process Y reads the
                                          uevents writes to devcd fd
                                          which results into writes to

                                         devcd_data_write()
                                           mod_delayed_work()
                                             try_to_grab_pending()
                                               del_timer()
                                                 debug_assert_init()
   INIT_DELAYED_WORK()
   schedule_delayed_work()
                                                   debug_object_fixup()
                                                     timer_fixup_assert_init()
                                                       timer_setup()
                                                         do_init_timer()
                                                       /*
                                                        Above call reinitializes
                                                        the timer to
                                                        timer-&gt;entry.pprev=NULL
                                                        and this will be checked
                                                        later in timer_pending() call.
                                                       */
                                                 timer_pending()
                                                  !hlist_unhashed_lockless(&amp;timer-&gt;entry)
                                                    !h-&gt;pprev
                                                /*
                                                  del_timer() checks h-&gt;pprev and finds
                                                  it to be NULL due to which
                                                  try_to_grab_pending() stucks.
                                                */

Link: https://lore.kernel.org/lkml/2e1f81e2-428c-f11f-ce92-eb11048cb271@quicinc.com/
Signed-off-by: Mukesh Ojha &lt;quic_mojha@quicinc.com&gt;
Link: https://lore.kernel.org/r/1663073424-13663-1-git-send-email-quic_mojha@quicinc.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Stable-dep-of: af54d778a038 ("devcoredump: Send uevent once devcd is ready")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>smb: client: fix potential NULL deref in parse_dfs_referrals()</title>
<updated>2023-12-13T17:18:17+00:00</updated>
<author>
<name>Paulo Alcantara</name>
<email>pc@manguebit.com</email>
</author>
<published>2023-12-06T00:49:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=d99376b70247394b39307051f994060a085a417e'/>
<id>d99376b70247394b39307051f994060a085a417e</id>
<content type='text'>
[ Upstream commit 92414333eb375ed64f4ae92d34d579e826936480 ]

If server returned no data for FSCTL_DFS_GET_REFERRALS, @dfs_rsp will
remain NULL and then parse_dfs_referrals() will dereference it.

Fix this by returning -EIO when no output data is returned.

Besides, we can't fix it in SMB2_ioctl() as some FSCTLs are allowed to
return no data as per MS-SMB2 2.2.32.

Fixes: 9d49640a21bf ("CIFS: implement get_dfs_refer for SMB2+")
Cc: stable@vger.kernel.org
Reported-by: Robert Morris &lt;rtm@csail.mit.edu&gt;
Signed-off-by: Paulo Alcantara (SUSE) &lt;pc@manguebit.com&gt;
Signed-off-by: Steve French &lt;stfrench@microsoft.com&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 92414333eb375ed64f4ae92d34d579e826936480 ]

If server returned no data for FSCTL_DFS_GET_REFERRALS, @dfs_rsp will
remain NULL and then parse_dfs_referrals() will dereference it.

Fix this by returning -EIO when no output data is returned.

Besides, we can't fix it in SMB2_ioctl() as some FSCTLs are allowed to
return no data as per MS-SMB2 2.2.32.

Fixes: 9d49640a21bf ("CIFS: implement get_dfs_refer for SMB2+")
Cc: stable@vger.kernel.org
Reported-by: Robert Morris &lt;rtm@csail.mit.edu&gt;
Signed-off-by: Paulo Alcantara (SUSE) &lt;pc@manguebit.com&gt;
Signed-off-by: Steve French &lt;stfrench@microsoft.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>cifs: Fix non-availability of dedup breaking generic/304</title>
<updated>2023-12-13T17:18:17+00:00</updated>
<author>
<name>David Howells</name>
<email>dhowells@redhat.com</email>
</author>
<published>2023-12-04T14:01:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=ab5813bb20711a8e3493b152e50b3dda3aed5858'/>
<id>ab5813bb20711a8e3493b152e50b3dda3aed5858</id>
<content type='text'>
[ Upstream commit 691a41d8da4b34fe72f09393505f55f28a8f34ec ]

Deduplication isn't supported on cifs, but cifs doesn't reject it, instead
treating it as extent duplication/cloning.  This can cause generic/304 to go
silly and run for hours on end.

Fix cifs to indicate EOPNOTSUPP if REMAP_FILE_DEDUP is set in
-&gt;remap_file_range().

Note that it's unclear whether or not commit b073a08016a1 is meant to cause
cifs to return an error if REMAP_FILE_DEDUP.

Fixes: b073a08016a1 ("cifs: fix that return -EINVAL when do dedupe operation")
Cc: stable@vger.kernel.org
Suggested-by: Dave Chinner &lt;david@fromorbit.com&gt;
cc: Xiaoli Feng &lt;fengxiaoli0714@gmail.com&gt;
cc: Shyam Prasad N &lt;nspmangalore@gmail.com&gt;
cc: Rohith Surabattula &lt;rohiths.msft@gmail.com&gt;
cc: Jeff Layton &lt;jlayton@kernel.org&gt;
cc: Darrick Wong &lt;darrick.wong@oracle.com&gt;
cc: fstests@vger.kernel.org
cc: linux-cifs@vger.kernel.org
cc: linux-fsdevel@vger.kernel.org
Link: https://lore.kernel.org/r/3876191.1701555260@warthog.procyon.org.uk/
Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
Signed-off-by: Steve French &lt;stfrench@microsoft.com&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 691a41d8da4b34fe72f09393505f55f28a8f34ec ]

Deduplication isn't supported on cifs, but cifs doesn't reject it, instead
treating it as extent duplication/cloning.  This can cause generic/304 to go
silly and run for hours on end.

Fix cifs to indicate EOPNOTSUPP if REMAP_FILE_DEDUP is set in
-&gt;remap_file_range().

Note that it's unclear whether or not commit b073a08016a1 is meant to cause
cifs to return an error if REMAP_FILE_DEDUP.

Fixes: b073a08016a1 ("cifs: fix that return -EINVAL when do dedupe operation")
Cc: stable@vger.kernel.org
Suggested-by: Dave Chinner &lt;david@fromorbit.com&gt;
cc: Xiaoli Feng &lt;fengxiaoli0714@gmail.com&gt;
cc: Shyam Prasad N &lt;nspmangalore@gmail.com&gt;
cc: Rohith Surabattula &lt;rohiths.msft@gmail.com&gt;
cc: Jeff Layton &lt;jlayton@kernel.org&gt;
cc: Darrick Wong &lt;darrick.wong@oracle.com&gt;
cc: fstests@vger.kernel.org
cc: linux-cifs@vger.kernel.org
cc: linux-fsdevel@vger.kernel.org
Link: https://lore.kernel.org/r/3876191.1701555260@warthog.procyon.org.uk/
Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
Signed-off-by: Steve French &lt;stfrench@microsoft.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Revert "btrfs: add dmesg output for first mount and last unmount of a filesystem"</title>
<updated>2023-12-13T17:18:17+00:00</updated>
<author>
<name>Greg Kroah-Hartman</name>
<email>gregkh@linuxfoundation.org</email>
</author>
<published>2023-12-11T14:52:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=bdee8b2805b8245b61fce6c44885a93931d06fde'/>
<id>bdee8b2805b8245b61fce6c44885a93931d06fde</id>
<content type='text'>
This reverts commit dd94ffab1b6d84b3ba9a8d09b6b0f44610d397eb which is
commit 2db313205f8b96eea467691917138d646bb50aef upstream.

As pointed out by many, the disk_super structure is NOT initialized
before it is dereferenced in the function
fs/btrfs/disk-io.c:open_ctree() that this commit adds, so something went
wrong here.

Revert it for now until it gets straightened out.

Link: https://lore.kernel.org/r/5b0eb360-3765-40e1-854a-9da6d97eb405@roeck-us.net
Link: https://lore.kernel.org/r/20231209172836.GA2154579@dev-arch.thelio-3990X
Reported-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Reported-by: Nathan Chancellor &lt;nathan@kernel.org&gt;
Cc: Anand Jain &lt;anand.jain@oracle.com&gt;
Cc: Qu Wenruo &lt;wqu@suse.com&gt;
Cc: David Sterba &lt;dsterba@suse.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>
This reverts commit dd94ffab1b6d84b3ba9a8d09b6b0f44610d397eb which is
commit 2db313205f8b96eea467691917138d646bb50aef upstream.

As pointed out by many, the disk_super structure is NOT initialized
before it is dereferenced in the function
fs/btrfs/disk-io.c:open_ctree() that this commit adds, so something went
wrong here.

Revert it for now until it gets straightened out.

Link: https://lore.kernel.org/r/5b0eb360-3765-40e1-854a-9da6d97eb405@roeck-us.net
Link: https://lore.kernel.org/r/20231209172836.GA2154579@dev-arch.thelio-3990X
Reported-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Reported-by: Nathan Chancellor &lt;nathan@kernel.org&gt;
Cc: Anand Jain &lt;anand.jain@oracle.com&gt;
Cc: Qu Wenruo &lt;wqu@suse.com&gt;
Cc: David Sterba &lt;dsterba@suse.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tools headers UAPI: Sync linux/perf_event.h with the kernel sources</title>
<updated>2023-12-13T17:18:17+00:00</updated>
<author>
<name>Namhyung Kim</name>
<email>namhyung@kernel.org</email>
</author>
<published>2022-08-19T00:36:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=dd9e851944aae32eff382777a4527d36922df64d'/>
<id>dd9e851944aae32eff382777a4527d36922df64d</id>
<content type='text'>
commit 65ba872a6971c11ceb342c3330f059289c0e6bdb upstream.

To pick the trivial change in:

  119a784c81270eb8 ("perf/core: Add a new read format to get a number of lost samples")

Signed-off-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
Acked-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Ian Rogers &lt;irogers@google.com&gt;
Cc: Ingo Molnar &lt;mingo@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Link: https://lore.kernel.org/r/20220819003644.508916-2-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.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 65ba872a6971c11ceb342c3330f059289c0e6bdb upstream.

To pick the trivial change in:

  119a784c81270eb8 ("perf/core: Add a new read format to get a number of lost samples")

Signed-off-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
Acked-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Ian Rogers &lt;irogers@google.com&gt;
Cc: Ingo Molnar &lt;mingo@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Link: https://lore.kernel.org/r/20220819003644.508916-2-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drop_monitor: Require 'CAP_SYS_ADMIN' when joining "events" group</title>
<updated>2023-12-13T17:18:17+00:00</updated>
<author>
<name>Ido Schimmel</name>
<email>idosch@nvidia.com</email>
</author>
<published>2023-12-11T12:41:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=4a341627a10959ef0db16f758bfd0d10fa9d73eb'/>
<id>4a341627a10959ef0db16f758bfd0d10fa9d73eb</id>
<content type='text'>
commit e03781879a0d524ce3126678d50a80484a513c4b upstream.

The "NET_DM" generic netlink family notifies drop locations over the
"events" multicast group. This is problematic since by default generic
netlink allows non-root users to listen to these notifications.

Fix by adding a new field to the generic netlink multicast group
structure that when set prevents non-root users or root without the
'CAP_SYS_ADMIN' capability (in the user namespace owning the network
namespace) from joining the group. Set this field for the "events"
group. Use 'CAP_SYS_ADMIN' rather than 'CAP_NET_ADMIN' because of the
nature of the information that is shared over this group.

Note that the capability check in this case will always be performed
against the initial user namespace since the family is not netns aware
and only operates in the initial network namespace.

A new field is added to the structure rather than using the "flags"
field because the existing field uses uAPI flags and it is inappropriate
to add a new uAPI flag for an internal kernel check. In net-next we can
rework the "flags" field to use internal flags and fold the new field
into it. But for now, in order to reduce the amount of changes, add a
new field.

Since the information can only be consumed by root, mark the control
plane operations that start and stop the tracing as root-only using the
'GENL_ADMIN_PERM' flag.

Tested using [1].

Before:

 # capsh -- -c ./dm_repo
 # capsh --drop=cap_sys_admin -- -c ./dm_repo

After:

 # capsh -- -c ./dm_repo
 # capsh --drop=cap_sys_admin -- -c ./dm_repo
 Failed to join "events" multicast group

[1]
 $ cat dm.c
 #include &lt;stdio.h&gt;
 #include &lt;netlink/genl/ctrl.h&gt;
 #include &lt;netlink/genl/genl.h&gt;
 #include &lt;netlink/socket.h&gt;

 int main(int argc, char **argv)
 {
 	struct nl_sock *sk;
 	int grp, err;

 	sk = nl_socket_alloc();
 	if (!sk) {
 		fprintf(stderr, "Failed to allocate socket\n");
 		return -1;
 	}

 	err = genl_connect(sk);
 	if (err) {
 		fprintf(stderr, "Failed to connect socket\n");
 		return err;
 	}

 	grp = genl_ctrl_resolve_grp(sk, "NET_DM", "events");
 	if (grp &lt; 0) {
 		fprintf(stderr,
 			"Failed to resolve \"events\" multicast group\n");
 		return grp;
 	}

 	err = nl_socket_add_memberships(sk, grp, NFNLGRP_NONE);
 	if (err) {
 		fprintf(stderr, "Failed to join \"events\" multicast group\n");
 		return err;
 	}

 	return 0;
 }
 $ gcc -I/usr/include/libnl3 -lnl-3 -lnl-genl-3 -o dm_repo dm.c

Fixes: 9a8afc8d3962 ("Network Drop Monitor: Adding drop monitor implementation &amp; Netlink protocol")
Reported-by: "The UK's National Cyber Security Centre (NCSC)" &lt;security@ncsc.gov.uk&gt;
Signed-off-by: Ido Schimmel &lt;idosch@nvidia.com&gt;
Reviewed-by: Jacob Keller &lt;jacob.e.keller@intel.com&gt;
Reviewed-by: Jiri Pirko &lt;jiri@nvidia.com&gt;
Link: https://lore.kernel.org/r/20231206213102.1824398-3-idosch@nvidia.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&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 e03781879a0d524ce3126678d50a80484a513c4b upstream.

The "NET_DM" generic netlink family notifies drop locations over the
"events" multicast group. This is problematic since by default generic
netlink allows non-root users to listen to these notifications.

Fix by adding a new field to the generic netlink multicast group
structure that when set prevents non-root users or root without the
'CAP_SYS_ADMIN' capability (in the user namespace owning the network
namespace) from joining the group. Set this field for the "events"
group. Use 'CAP_SYS_ADMIN' rather than 'CAP_NET_ADMIN' because of the
nature of the information that is shared over this group.

Note that the capability check in this case will always be performed
against the initial user namespace since the family is not netns aware
and only operates in the initial network namespace.

A new field is added to the structure rather than using the "flags"
field because the existing field uses uAPI flags and it is inappropriate
to add a new uAPI flag for an internal kernel check. In net-next we can
rework the "flags" field to use internal flags and fold the new field
into it. But for now, in order to reduce the amount of changes, add a
new field.

Since the information can only be consumed by root, mark the control
plane operations that start and stop the tracing as root-only using the
'GENL_ADMIN_PERM' flag.

Tested using [1].

Before:

 # capsh -- -c ./dm_repo
 # capsh --drop=cap_sys_admin -- -c ./dm_repo

After:

 # capsh -- -c ./dm_repo
 # capsh --drop=cap_sys_admin -- -c ./dm_repo
 Failed to join "events" multicast group

[1]
 $ cat dm.c
 #include &lt;stdio.h&gt;
 #include &lt;netlink/genl/ctrl.h&gt;
 #include &lt;netlink/genl/genl.h&gt;
 #include &lt;netlink/socket.h&gt;

 int main(int argc, char **argv)
 {
 	struct nl_sock *sk;
 	int grp, err;

 	sk = nl_socket_alloc();
 	if (!sk) {
 		fprintf(stderr, "Failed to allocate socket\n");
 		return -1;
 	}

 	err = genl_connect(sk);
 	if (err) {
 		fprintf(stderr, "Failed to connect socket\n");
 		return err;
 	}

 	grp = genl_ctrl_resolve_grp(sk, "NET_DM", "events");
 	if (grp &lt; 0) {
 		fprintf(stderr,
 			"Failed to resolve \"events\" multicast group\n");
 		return grp;
 	}

 	err = nl_socket_add_memberships(sk, grp, NFNLGRP_NONE);
 	if (err) {
 		fprintf(stderr, "Failed to join \"events\" multicast group\n");
 		return err;
 	}

 	return 0;
 }
 $ gcc -I/usr/include/libnl3 -lnl-3 -lnl-genl-3 -o dm_repo dm.c

Fixes: 9a8afc8d3962 ("Network Drop Monitor: Adding drop monitor implementation &amp; Netlink protocol")
Reported-by: "The UK's National Cyber Security Centre (NCSC)" &lt;security@ncsc.gov.uk&gt;
Signed-off-by: Ido Schimmel &lt;idosch@nvidia.com&gt;
Reviewed-by: Jacob Keller &lt;jacob.e.keller@intel.com&gt;
Reviewed-by: Jiri Pirko &lt;jiri@nvidia.com&gt;
Link: https://lore.kernel.org/r/20231206213102.1824398-3-idosch@nvidia.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>psample: Require 'CAP_NET_ADMIN' when joining "packets" group</title>
<updated>2023-12-13T17:18:17+00:00</updated>
<author>
<name>Ido Schimmel</name>
<email>idosch@nvidia.com</email>
</author>
<published>2023-12-11T12:41:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=fe8402511ed80ce9a7ee696f457a3d856d52cd47'/>
<id>fe8402511ed80ce9a7ee696f457a3d856d52cd47</id>
<content type='text'>
commit 44ec98ea5ea9cfecd31a5c4cc124703cb5442832 upstream.

The "psample" generic netlink family notifies sampled packets over the
"packets" multicast group. This is problematic since by default generic
netlink allows non-root users to listen to these notifications.

Fix by marking the group with the 'GENL_UNS_ADMIN_PERM' flag. This will
prevent non-root users or root without the 'CAP_NET_ADMIN' capability
(in the user namespace owning the network namespace) from joining the
group.

Tested using [1].

Before:

 # capsh -- -c ./psample_repo
 # capsh --drop=cap_net_admin -- -c ./psample_repo

After:

 # capsh -- -c ./psample_repo
 # capsh --drop=cap_net_admin -- -c ./psample_repo
 Failed to join "packets" multicast group

[1]
 $ cat psample.c
 #include &lt;stdio.h&gt;
 #include &lt;netlink/genl/ctrl.h&gt;
 #include &lt;netlink/genl/genl.h&gt;
 #include &lt;netlink/socket.h&gt;

 int join_grp(struct nl_sock *sk, const char *grp_name)
 {
 	int grp, err;

 	grp = genl_ctrl_resolve_grp(sk, "psample", grp_name);
 	if (grp &lt; 0) {
 		fprintf(stderr, "Failed to resolve \"%s\" multicast group\n",
 			grp_name);
 		return grp;
 	}

 	err = nl_socket_add_memberships(sk, grp, NFNLGRP_NONE);
 	if (err) {
 		fprintf(stderr, "Failed to join \"%s\" multicast group\n",
 			grp_name);
 		return err;
 	}

 	return 0;
 }

 int main(int argc, char **argv)
 {
 	struct nl_sock *sk;
 	int err;

 	sk = nl_socket_alloc();
 	if (!sk) {
 		fprintf(stderr, "Failed to allocate socket\n");
 		return -1;
 	}

 	err = genl_connect(sk);
 	if (err) {
 		fprintf(stderr, "Failed to connect socket\n");
 		return err;
 	}

 	err = join_grp(sk, "config");
 	if (err)
 		return err;

 	err = join_grp(sk, "packets");
 	if (err)
 		return err;

 	return 0;
 }
 $ gcc -I/usr/include/libnl3 -lnl-3 -lnl-genl-3 -o psample_repo psample.c

Fixes: 6ae0a6286171 ("net: Introduce psample, a new genetlink channel for packet sampling")
Reported-by: "The UK's National Cyber Security Centre (NCSC)" &lt;security@ncsc.gov.uk&gt;
Signed-off-by: Ido Schimmel &lt;idosch@nvidia.com&gt;
Reviewed-by: Jacob Keller &lt;jacob.e.keller@intel.com&gt;
Reviewed-by: Jiri Pirko &lt;jiri@nvidia.com&gt;
Link: https://lore.kernel.org/r/20231206213102.1824398-2-idosch@nvidia.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&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 44ec98ea5ea9cfecd31a5c4cc124703cb5442832 upstream.

The "psample" generic netlink family notifies sampled packets over the
"packets" multicast group. This is problematic since by default generic
netlink allows non-root users to listen to these notifications.

Fix by marking the group with the 'GENL_UNS_ADMIN_PERM' flag. This will
prevent non-root users or root without the 'CAP_NET_ADMIN' capability
(in the user namespace owning the network namespace) from joining the
group.

Tested using [1].

Before:

 # capsh -- -c ./psample_repo
 # capsh --drop=cap_net_admin -- -c ./psample_repo

After:

 # capsh -- -c ./psample_repo
 # capsh --drop=cap_net_admin -- -c ./psample_repo
 Failed to join "packets" multicast group

[1]
 $ cat psample.c
 #include &lt;stdio.h&gt;
 #include &lt;netlink/genl/ctrl.h&gt;
 #include &lt;netlink/genl/genl.h&gt;
 #include &lt;netlink/socket.h&gt;

 int join_grp(struct nl_sock *sk, const char *grp_name)
 {
 	int grp, err;

 	grp = genl_ctrl_resolve_grp(sk, "psample", grp_name);
 	if (grp &lt; 0) {
 		fprintf(stderr, "Failed to resolve \"%s\" multicast group\n",
 			grp_name);
 		return grp;
 	}

 	err = nl_socket_add_memberships(sk, grp, NFNLGRP_NONE);
 	if (err) {
 		fprintf(stderr, "Failed to join \"%s\" multicast group\n",
 			grp_name);
 		return err;
 	}

 	return 0;
 }

 int main(int argc, char **argv)
 {
 	struct nl_sock *sk;
 	int err;

 	sk = nl_socket_alloc();
 	if (!sk) {
 		fprintf(stderr, "Failed to allocate socket\n");
 		return -1;
 	}

 	err = genl_connect(sk);
 	if (err) {
 		fprintf(stderr, "Failed to connect socket\n");
 		return err;
 	}

 	err = join_grp(sk, "config");
 	if (err)
 		return err;

 	err = join_grp(sk, "packets");
 	if (err)
 		return err;

 	return 0;
 }
 $ gcc -I/usr/include/libnl3 -lnl-3 -lnl-genl-3 -o psample_repo psample.c

Fixes: 6ae0a6286171 ("net: Introduce psample, a new genetlink channel for packet sampling")
Reported-by: "The UK's National Cyber Security Centre (NCSC)" &lt;security@ncsc.gov.uk&gt;
Signed-off-by: Ido Schimmel &lt;idosch@nvidia.com&gt;
Reviewed-by: Jacob Keller &lt;jacob.e.keller@intel.com&gt;
Reviewed-by: Jiri Pirko &lt;jiri@nvidia.com&gt;
Link: https://lore.kernel.org/r/20231206213102.1824398-2-idosch@nvidia.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>genetlink: add CAP_NET_ADMIN test for multicast bind</title>
<updated>2023-12-13T17:18:17+00:00</updated>
<author>
<name>Ido Schimmel</name>
<email>idosch@nvidia.com</email>
</author>
<published>2023-12-11T12:41:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=263bffd2b6aad5deedb5b65b1dab02f09052be66'/>
<id>263bffd2b6aad5deedb5b65b1dab02f09052be66</id>
<content type='text'>
This is a partial backport of upstream commit 4d54cc32112d ("mptcp:
avoid lock_fast usage in accept path"). It is only a partial backport
because the patch in the link below was erroneously squash-merged into
upstream commit 4d54cc32112d ("mptcp: avoid lock_fast usage in accept
path"). Below is the original patch description from Florian Westphal:

"
genetlink sets NL_CFG_F_NONROOT_RECV for its netlink socket so anyone can
subscribe to multicast messages.

rtnetlink doesn't allow this unconditionally,  rtnetlink_bind() restricts
bind requests to CAP_NET_ADMIN for a few groups.

This allows to set GENL_UNS_ADMIN_PERM flag on genl mcast groups to
mandate CAP_NET_ADMIN.

This will be used by the upcoming mptcp netlink event facility which
exposes the token (mptcp connection identifier) to userspace.
"

Link: https://lore.kernel.org/mptcp/20210213000001.379332-8-mathew.j.martineau@linux.intel.com/
Signed-off-by: Ido Schimmel &lt;idosch@nvidia.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>
This is a partial backport of upstream commit 4d54cc32112d ("mptcp:
avoid lock_fast usage in accept path"). It is only a partial backport
because the patch in the link below was erroneously squash-merged into
upstream commit 4d54cc32112d ("mptcp: avoid lock_fast usage in accept
path"). Below is the original patch description from Florian Westphal:

"
genetlink sets NL_CFG_F_NONROOT_RECV for its netlink socket so anyone can
subscribe to multicast messages.

rtnetlink doesn't allow this unconditionally,  rtnetlink_bind() restricts
bind requests to CAP_NET_ADMIN for a few groups.

This allows to set GENL_UNS_ADMIN_PERM flag on genl mcast groups to
mandate CAP_NET_ADMIN.

This will be used by the upcoming mptcp netlink event facility which
exposes the token (mptcp connection identifier) to userspace.
"

Link: https://lore.kernel.org/mptcp/20210213000001.379332-8-mathew.j.martineau@linux.intel.com/
Signed-off-by: Ido Schimmel &lt;idosch@nvidia.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
