[ Upstream commit 114b4bb1cc ]
Following patch is going to use RCU instead of
sock_diag_table_mutex acquisition.
This patch is a preparation, no change of behavior yet.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Guillaume Nault <gnault@redhat.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Stable-dep-of: eb02688c5c ("ipv6: release nexthop on device removal")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 1904fb9ebf ]
Netlink supports iterative dumping of data. It provides the families
the following ops:
- start - (optional) kicks off the dumping process
- dump - actual dump helper, keeps getting called until it returns 0
- done - (optional) pairs with .start, can be used for cleanup
The whole process is asynchronous and the repeated calls to .dump
don't actually happen in a tight loop, but rather are triggered
in response to recvmsg() on the socket.
This gives the user full control over the dump, but also means that
the user can close the socket without getting to the end of the dump.
To make sure .start is always paired with .done we check if there
is an ongoing dump before freeing the socket, and if so call .done.
The complication is that sockets can get freed from BH and .done
is allowed to sleep. So we use a workqueue to defer the call, when
needed.
Unfortunately this does not work correctly. What we defer is not
the cleanup but rather releasing a reference on the socket.
We have no guarantee that we own the last reference, if someone
else holds the socket they may release it in BH and we're back
to square one.
The whole dance, however, appears to be unnecessary. Only the user
can interact with dumps, so we can clean up when socket is closed.
And close always happens in process context. Some async code may
still access the socket after close, queue notification skbs to it etc.
but no dumps can start, end or otherwise make progress.
Delete the workqueue and flush the dump state directly from the release
handler. Note that further cleanup is possible in -next, for instance
we now always call .done before releasing the main module reference,
so dump doesn't have to take a reference of its own.
Reported-by: syzkaller <syzkaller@googlegroups.com>
Fixes: ed5d7788a9 ("netlink: Do not schedule work from sk_destruct")
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20241106015235.2458807-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 1dae9f1187 upstream.
The kernel may crash when deleting a genetlink family if there are still
listeners for that family:
Oops: Kernel access of bad area, sig: 11 [#1]
...
NIP [c000000000c080bc] netlink_update_socket_mc+0x3c/0xc0
LR [c000000000c0f764] __netlink_clear_multicast_users+0x74/0xc0
Call Trace:
__netlink_clear_multicast_users+0x74/0xc0
genl_unregister_family+0xd4/0x2d0
Change the unsafe loop on the list to a safe one, because inside the
loop there is an element removal from this list.
Fixes: b8273570f8 ("genetlink: fix netns vs. netlink table locking (2)")
Cc: stable@vger.kernel.org
Signed-off-by: Anastasia Kovaleva <a.kovaleva@yadro.com>
Reviewed-by: Dmitry Bogdanov <d.bogdanov@yadro.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20241003104431.12391-1-a.kovaleva@yadro.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit b559027006 ]
__netlink_dump_start() releases nlk->cb_mutex right before
calling netlink_dump() which grabs it again.
This seems dangerous, even if KASAN did not bother yet.
Add a @lock_taken parameter to netlink_dump() to let it
grab the mutex if called from netlink_recvmsg() only.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 234ec0b603 ]
I analyze the potential sleeping issue of the following processes:
Thread A Thread B
... netlink_create //ref = 1
do_mq_notify ...
sock = netlink_getsockbyfilp ... //ref = 2
info->notify_sock = sock; ...
... netlink_sendmsg
... skb = netlink_alloc_large_skb //skb->head is vmalloced
... netlink_unicast
... sk = netlink_getsockbyportid //ref = 3
... netlink_sendskb
... __netlink_sendskb
... skb_queue_tail //put skb to sk_receive_queue
... sock_put //ref = 2
... ...
... netlink_release
... deferred_put_nlk_sk //ref = 1
mqueue_flush_file
spin_lock
remove_notification
netlink_sendskb
sock_put //ref = 0
sk_free
...
__sk_destruct
netlink_sock_destruct
skb_queue_purge //get skb from sk_receive_queue
...
__skb_queue_purge_reason
kfree_skb_reason
__kfree_skb
...
skb_release_all
skb_release_head_state
netlink_skb_destructor
vfree(skb->head) //sleeping while holding spinlock
In netlink_sendmsg, if the memory pointed to by skb->head is allocated by
vmalloc, and is put to sk_receive_queue queue, also the skb is not freed.
When the mqueue executes flush, the sleeping bug will occur. Use
vfree_atomic instead of vfree in netlink_skb_destructor to solve the issue.
Fixes: c05cdb1b86 ("netlink: allow large data transfers from user-space")
Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com>
Link: https://lore.kernel.org/r/20240122011807.2110357-1-shaozhengchao@huawei.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit e03781879a ]
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 <stdio.h>
#include <netlink/genl/ctrl.h>
#include <netlink/genl/genl.h>
#include <netlink/socket.h>
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 < 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: 9a8afc8d39 ("Network Drop Monitor: Adding drop monitor implementation & Netlink protocol")
Reported-by: "The UK's National Cyber Security Centre (NCSC)" <security@ncsc.gov.uk>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Link: https://lore.kernel.org/r/20231206213102.1824398-3-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit c73a72f4cb upstream.
I've added a flex array to struct nlmsghdr in
commit 738136a0e3 ("netlink: split up copies in the ack construction")
to allow accessing the data easily. It leads to warnings with clang,
if user space wraps this structure into another struct and the flex
array is not at the end of the container.
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/all/20221114023927.GA685@u2004-local/
Link: https://lore.kernel.org/r/20221118033903.1651026-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 738136a0e3 ]
Clean up the use of unsafe_memcpy() by adding a flexible array
at the end of netlink message header and splitting up the header
and data copies.
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stable-dep-of: d0f95894fd ("netlink: annotate data-races around sk->sk_err")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 8fe08d70a2 ]
sk_diag_put_flags(), netlink_setsockopt(), netlink_getsockopt()
and others use nlk->flags without correct locking.
Use set_bit(), clear_bit(), test_bit(), assign_bit() to remove
data-races.
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 8d61f926d4 ]
syzbot reported a possible deadlock in netlink_set_err() [1]
A similar issue was fixed in commit 1d482e666b ("netlink: disable IRQs
for netlink_lock_table()") in netlink_lock_table()
This patch adds IRQ safety to netlink_set_err() and __netlink_diag_dump()
which were not covered by cited commit.
[1]
WARNING: possible irq lock inversion dependency detected
6.4.0-rc6-syzkaller-00240-g4e9f0ec38852 #0 Not tainted
syz-executor.2/23011 just changed the state of lock:
ffffffff8e1a7a58 (nl_table_lock){.+.?}-{2:2}, at: netlink_set_err+0x2e/0x3a0 net/netlink/af_netlink.c:1612
but this lock was taken by another, SOFTIRQ-safe lock in the past:
(&local->queue_stop_reason_lock){..-.}-{2:2}
and interrupts could create inverse lock ordering between them.
other info that might help us debug this:
Possible interrupt unsafe locking scenario:
CPU0 CPU1
---- ----
lock(nl_table_lock);
local_irq_disable();
lock(&local->queue_stop_reason_lock);
lock(nl_table_lock);
<Interrupt>
lock(&local->queue_stop_reason_lock);
*** DEADLOCK ***
Fixes: 1d482e666b ("netlink: disable IRQs for netlink_lock_table()")
Reported-by: syzbot+a7d200a347f912723e5c@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?extid=a7d200a347f912723e5c
Link: https://lore.kernel.org/netdev/000000000000e38d1605fea5747e@google.com/T/#u
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Johannes Berg <johannes.berg@intel.com>
Link: https://lore.kernel.org/r/20230621154337.1668594-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit f4e4534850 ]
The current code for the length calculation wrongly truncates the reported
length of the groups array, causing an under report of the subscribed
groups. To fix this, use 'BITS_TO_BYTES()' which rounds up the
division by 8.
Fixes: b42be38b27 ("netlink: add API to retrieve all group memberships")
Signed-off-by: Pedro Tammela <pctammela@mojatatu.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Link: https://lore.kernel.org/r/20230529153335.389815-1-pctammela@mojatatu.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit d913d32cc2 ]
Brad Spencer provided a detailed report [0] that when calling getsockopt()
for AF_NETLINK, some SOL_NETLINK options set only 1 byte even though such
options require at least sizeof(int) as length.
The options return a flag value that fits into 1 byte, but such behaviour
confuses users who do not initialise the variable before calling
getsockopt() and do not strictly check the returned value as char.
Currently, netlink_getsockopt() uses put_user() to copy data to optlen and
optval, but put_user() casts the data based on the pointer, char *optval.
As a result, only 1 byte is set to optval.
To avoid this behaviour, we need to use copy_to_user() or cast optval for
put_user().
Note that this changes the behaviour on big-endian systems, but we document
that the size of optval is int in the man page.
$ man 7 netlink
...
Socket options
To set or get a netlink socket option, call getsockopt(2) to read
or setsockopt(2) to write the option with the option level argument
set to SOL_NETLINK. Unless otherwise noted, optval is a pointer to
an int.
Fixes: 9a4595bc7e ("[NETLINK]: Add set/getsockopt options to support more than 32 groups")
Fixes: be0c22a46c ("netlink: add NETLINK_BROADCAST_ERROR socket option")
Fixes: 38938bfe34 ("netlink: add NETLINK_NO_ENOBUFS socket flag")
Fixes: 0a6a3a23ea ("netlink: add NETLINK_CAP_ACK socket option")
Fixes: 2d4bc93368 ("netlink: extended ACK reporting")
Fixes: 89d35528d1 ("netlink: Add new socket option to enable strict checking on dumps")
Reported-by: Brad Spencer <bspencer@blackberry.com>
Link: https://lore.kernel.org/netdev/ZD7VkNWFfp22kTDt@datsun.rim.net/
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Link: https://lore.kernel.org/r/20230421185255.94606-1-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 004db64d18 ]
netlink_getname(), netlink_sendmsg() and netlink_getsockbyportid()
can read nlk->dst_portid and nlk->dst_group while another
thread is changing them.
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
To keep backward compatibility we used to leave attribute parsing
to the family if no policy is specified. This becomes tedious as
we move to more strict validation. Families must define reject all
policies if they don't want any attributes accepted.
Piggy back on the resv_start_op field as the switchover point.
AFAICT only ethtool has added new commands since the resv_start_op
was defined, and it has per-op policies so this should be a no-op.
Nonetheless the patch should still go into v6.1 for consistency.
Link: https://lore.kernel.org/all/20221019125745.3f2e7659@kernel.org/
Link: https://lore.kernel.org/r/20221021193532.1511293-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Commit 9c5d03d362 ("genetlink: start to validate reserved header bytes")
introduced extra validation for genetlink headers. We had to gate it
to only apply to new commands, to maintain bug-wards compatibility.
Use this opportunity (before the new checks make it to Linus's tree)
to add more conditions.
Validate that Generic Netlink families do not use nlmsg_flags outside
of the well-understood set.
Link: https://lore.kernel.org/all/20220928073709.1b93b74a@kernel.org/
Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Reviewed-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Reviewed-by: Guillaume Nault <gnault@redhat.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Link: https://lore.kernel.org/r/20220929142809.1167546-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
In preparation for FORTIFY_SOURCE doing bounds-check on memcpy(),
switch from __nlmsg_put to nlmsg_put(), and explain the bounds check
for dealing with the memcpy() across a composite flexible array struct.
Avoids this future run-time warning:
memcpy: detected field-spanning write (size 32) of single field "&errmsg->msg" at net/netlink/af_netlink.c:2447 (size 16)
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: Jozsef Kadlecsik <kadlec@netfilter.org>
Cc: Florian Westphal <fw@strlen.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: syzbot <syzkaller@googlegroups.com>
Cc: netfilter-devel@vger.kernel.org
Cc: coreteam@netfilter.org
Cc: netdev@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220901071336.1418572-1-keescook@chromium.org
Signed-off-by: David S. Miller <davem@davemloft.net>
There is currently no way to report via extack in a structured way
that an attribute is missing. This leads to families resorting to
string messages.
Add a pair of attributes - @offset and @type for machine-readable
way of reporting missing attributes. The @offset points to the
nest which should have contained the attribute, @type is the
expected nla_type. The offset will be skipped if the attribute
is missing at the message level rather than inside a nest.
User space should be able to figure out which attribute enum
(AKA attribute space AKA attribute set) the nest pointed to by
@offset is using.
Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
The ext_ack writing code looks very "organically grown".
Move the calculation of the size and writing out to helpers.
This is more idiomatic and gives us the ability to return early
avoiding the long (and randomly ordered) "if" conditions.
Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
We had historically not checked that genlmsghdr.reserved
is 0 on input which prevents us from using those precious
bytes in the future.
One use case would be to extend the cmd field, which is
currently just 8 bits wide and 256 is not a lot of commands
for some core families.
To make sure that new families do the right thing by default
put the onus of opting out of validation on existing families.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Paul Moore <paul@paul-moore.com> (NetLabel)
Signed-off-by: David S. Miller <davem@davemloft.net>
In genl_bind(), currently genl_lock and write cb_lock are taken
for iteration of genl_fam_idr and processing of static values
stored in struct genl_family. Take just read cb_lock for this task
as it is sufficient to guard the idr and the struct against
concurrent genl_register/unregister_family() calls.
This will allow to run genl command processing in genl_rcv() and
mnl_socket_setsockopt(.., NETLINK_ADD_MEMBERSHIP, ..) in parallel.
Reported-by: Vikas Gupta <vikas.gupta@broadcom.com>
Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Link: https://lore.kernel.org/r/20220825081940.1283335-1-jiri@resnulli.us
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
netlink_recvmsg() does not need to change transport header.
If transport header was needed, it should have been reset
by the producer (netlink_dump()), not the consumer(s).
The following trace probably happened when multiple threads
were using MSG_PEEK.
BUG: KCSAN: data-race in netlink_recvmsg / netlink_recvmsg
write to 0xffff88811e9f15b2 of 2 bytes by task 32012 on cpu 1:
skb_reset_transport_header include/linux/skbuff.h:2760 [inline]
netlink_recvmsg+0x1de/0x790 net/netlink/af_netlink.c:1978
sock_recvmsg_nosec net/socket.c:948 [inline]
sock_recvmsg net/socket.c:966 [inline]
__sys_recvfrom+0x204/0x2c0 net/socket.c:2097
__do_sys_recvfrom net/socket.c:2115 [inline]
__se_sys_recvfrom net/socket.c:2111 [inline]
__x64_sys_recvfrom+0x74/0x90 net/socket.c:2111
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
write to 0xffff88811e9f15b2 of 2 bytes by task 32005 on cpu 0:
skb_reset_transport_header include/linux/skbuff.h:2760 [inline]
netlink_recvmsg+0x1de/0x790 net/netlink/af_netlink.c:1978
____sys_recvmsg+0x162/0x2f0
___sys_recvmsg net/socket.c:2674 [inline]
__sys_recvmsg+0x209/0x3f0 net/socket.c:2704
__do_sys_recvmsg net/socket.c:2714 [inline]
__se_sys_recvmsg net/socket.c:2711 [inline]
__x64_sys_recvmsg+0x42/0x50 net/socket.c:2711
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
value changed: 0xffff -> 0x0000
Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 32005 Comm: syz-executor.4 Not tainted 5.18.0-rc1-syzkaller-00328-ge1f700ebd6be-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Link: https://lore.kernel.org/r/20220505161946.2867638-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
skb_recv_datagram() has two parameters 'flags' and 'noblock' that are
merged inside skb_recv_datagram() by 'flags | (noblock ? MSG_DONTWAIT : 0)'
As 'flags' may contain MSG_DONTWAIT as value most callers split the 'flags'
into 'flags' and 'noblock' with finally obsolete bit operations like this:
skb_recv_datagram(sk, flags & ~MSG_DONTWAIT, flags & MSG_DONTWAIT, &rc);
And this is not even done consistently with the 'flags' parameter.
This patch removes the obsolete and costly splitting into two parameters
and only performs bit operations when really needed on the caller side.
One missing conversion thankfully reported by kernel test robot. I missed
to enable kunit tests to build the mctp code.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
When a netlink message is received, netlink_recvmsg() fills in the address
of the sender. One of the fields is the 32-bit bitfield nl_groups, which
carries the multicast group on which the message was received. The least
significant bit corresponds to group 1, and therefore the highest group
that the field can represent is 32. Above that, the UB sanitizer flags the
out-of-bounds shift attempts.
Which bits end up being set in such case is implementation defined, but
it's either going to be a wrong non-zero value, or zero, which is at least
not misleading. Make the latter choice deterministic by always setting to 0
for higher-numbered multicast groups.
To get information about membership in groups >= 32, userspace is expected
to use nl_pktinfo control messages[0], which are enabled by NETLINK_PKTINFO
socket option.
[0] https://lwn.net/Articles/147608/
The way to trigger this issue is e.g. through monitoring the BRVLAN group:
# bridge monitor vlan &
# ip link add name br type bridge
Which produces the following citation:
UBSAN: shift-out-of-bounds in net/netlink/af_netlink.c:162:19
shift exponent 32 is too large for 32-bit type 'int'
Fixes: f7fa9b10ed ("[NETLINK]: Support dynamic number of multicast groups per netlink family")
Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://lore.kernel.org/r/2bef6aabf201d1fc16cca139a744700cff9dcb04.1647527635.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
sock.h is pretty heavily used (5k objects rebuilt on x86 after
it's touched). We can drop the include of filter.h from it and
add a forward declaration of struct sk_filter instead.
This decreases the number of rebuilt objects when bpf.h
is touched from ~5k to ~1k.
There's a lot of missing includes this was masking. Primarily
in networking tho, this time.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Acked-by: Stefano Garzarella <sgarzare@redhat.com>
Link: https://lore.kernel.org/bpf/20211229004913.513372-1-kuba@kernel.org
This is distracting really, let's make this simpler,
because many callers had to take care of this
by themselves, even if on x86 this adds more
code than really needed.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
While existing code is correct, KCSAN is reporting
a data-race in netlink_insert / netlink_sendmsg [1]
It is correct to read nlk->bound without a lock, as netlink_autobind()
will acquire all needed locks.
[1]
BUG: KCSAN: data-race in netlink_insert / netlink_sendmsg
write to 0xffff8881031c8b30 of 1 bytes by task 18752 on cpu 0:
netlink_insert+0x5cc/0x7f0 net/netlink/af_netlink.c:597
netlink_autobind+0xa9/0x150 net/netlink/af_netlink.c:842
netlink_sendmsg+0x479/0x7c0 net/netlink/af_netlink.c:1892
sock_sendmsg_nosec net/socket.c:703 [inline]
sock_sendmsg net/socket.c:723 [inline]
____sys_sendmsg+0x360/0x4d0 net/socket.c:2392
___sys_sendmsg net/socket.c:2446 [inline]
__sys_sendmsg+0x1ed/0x270 net/socket.c:2475
__do_sys_sendmsg net/socket.c:2484 [inline]
__se_sys_sendmsg net/socket.c:2482 [inline]
__x64_sys_sendmsg+0x42/0x50 net/socket.c:2482
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
read to 0xffff8881031c8b30 of 1 bytes by task 18751 on cpu 1:
netlink_sendmsg+0x270/0x7c0 net/netlink/af_netlink.c:1891
sock_sendmsg_nosec net/socket.c:703 [inline]
sock_sendmsg net/socket.c:723 [inline]
__sys_sendto+0x2a8/0x370 net/socket.c:2019
__do_sys_sendto net/socket.c:2031 [inline]
__se_sys_sendto net/socket.c:2027 [inline]
__x64_sys_sendto+0x74/0x90 net/socket.c:2027
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
value changed: 0x00 -> 0x01
Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 18751 Comm: syz-executor.0 Not tainted 5.14.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Fixes: da314c9923 ("netlink: Replace rhash_portid with bound")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
No users in tree since commit a3498436b3 ("netns: restrict uevents"),
so remove this functionality.
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add the case when nlh is NULL in nlmsg_report(),
so that the caller doesn't need to deal with this case.
Signed-off-by: Yajun Deng <yajun.deng@linux.dev>
Signed-off-by: David S. Miller <davem@davemloft.net>
Yonghong Song report:
The bpf selftest tc_bpf failed with latest bpf-next.
The following is the command to run and the result:
$ ./test_progs -n 132
[ 40.947571] bpf_testmod: loading out-of-tree module taints kernel.
test_tc_bpf:PASS:test_tc_bpf__open_and_load 0 nsec
test_tc_bpf:PASS:bpf_tc_hook_create(BPF_TC_INGRESS) 0 nsec
test_tc_bpf:PASS:bpf_tc_hook_create invalid hook.attach_point 0 nsec
test_tc_bpf_basic:PASS:bpf_obj_get_info_by_fd 0 nsec
test_tc_bpf_basic:PASS:bpf_tc_attach 0 nsec
test_tc_bpf_basic:PASS:handle set 0 nsec
test_tc_bpf_basic:PASS:priority set 0 nsec
test_tc_bpf_basic:PASS:prog_id set 0 nsec
test_tc_bpf_basic:PASS:bpf_tc_attach replace mode 0 nsec
test_tc_bpf_basic:PASS:bpf_tc_query 0 nsec
test_tc_bpf_basic:PASS:handle set 0 nsec
test_tc_bpf_basic:PASS:priority set 0 nsec
test_tc_bpf_basic:PASS:prog_id set 0 nsec
libbpf: Kernel error message: Failed to send filter delete notification
test_tc_bpf_basic:FAIL:bpf_tc_detach unexpected error: -3 (errno 3)
test_tc_bpf:FAIL:test_tc_internal ingress unexpected error: -3 (errno 3)
The failure seems due to the commit
cfdf0d9ae7 ("rtnetlink: use nlmsg_notify() in rtnetlink_send()")
Deal with ESRCH error in nlmsg_notify() even the report variable is zero.
Reported-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Yajun Deng <yajun.deng@linux.dev>
Link: https://lore.kernel.org/r/20210719051816.11762-1-yajun.deng@linux.dev
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
It has 'if (err >0 )' statement in nlmsg_unicast(), so use nlmsg_unicast()
instead of netlink_unicast(), this looks more concise.
v2: remove the change in netfilter.
Signed-off-by: Yajun Deng <yajun.deng@linux.dev>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch introduces a function wrapper to call the sk_error_report
callback. That will prepare to add additional handling whenever
sk_error_report is called, for example to trace socket errors.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Syzbot reports that in mac80211 we have a potential deadlock
between our "local->stop_queue_reasons_lock" (spinlock) and
netlink's nl_table_lock (rwlock). This is because there's at
least one situation in which we might try to send a netlink
message with this spinlock held while it is also possible to
take the spinlock from a hardirq context, resulting in the
following deadlock scenario reported by lockdep:
CPU0 CPU1
---- ----
lock(nl_table_lock);
local_irq_disable();
lock(&local->queue_stop_reason_lock);
lock(nl_table_lock);
<Interrupt>
lock(&local->queue_stop_reason_lock);
This seems valid, we can take the queue_stop_reason_lock in
any kind of context ("CPU0"), and call ieee80211_report_ack_skb()
with the spinlock held and IRQs disabled ("CPU1") in some
code path (ieee80211_do_stop() via ieee80211_free_txskb()).
Short of disallowing netlink use in scenarios like these
(which would be rather complex in mac80211's case due to
the deep callchain), it seems the only fix for this is to
disable IRQs while nl_table_lock is held to avoid hitting
this scenario, this disallows the "CPU0" portion of the
reported deadlock.
Note that the writer side (netlink_table_grab()) already
disables IRQs for this lock.
Unfortunately though, this seems like a huge hammer, and
maybe the whole netlink table locking should be reworked.
Reported-by: syzbot+69ff9dff50dcfe14ddd4@syzkaller.appspotmail.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
