Revert struct sockaddr from flexible array to fixed 14-byte "sa_data",
to solve over 36,000 -Wflex-array-member-not-at-end warnings, since
struct sockaddr is embedded within many network structs.
With socket/proto sockaddr-based internal APIs switched to use struct
sockaddr_unsized, there should be no more uses of struct sockaddr that
depend on reading beyond the end of struct sockaddr::sa_data that might
trigger bounds checking.
Comparing an x86_64 "allyesconfig" vmlinux build before and after this
patch showed no new "ud1" instructions from CONFIG_UBSAN_BOUNDS nor any
new "field-spanning" memcpy CONFIG_FORTIFY_SOURCE instrumentations.
Cc: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Kees Cook <kees@kernel.org>
Link: https://patch.msgid.link/20251104002617.2752303-8-kees@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Update all struct proto_ops bind() callback function prototypes from
"struct sockaddr *" to "struct sockaddr_unsized *" to avoid lying to the
compiler about object sizes. Calls into struct proto handlers gain casts
that will be removed in the struct proto conversion patch.
No binary changes expected.
Signed-off-by: Kees Cook <kees@kernel.org>
Link: https://patch.msgid.link/20251104002617.2752303-2-kees@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
In a system with high real-time requirements, the timeout mechanism of
ordinary timers with jiffies granularity is insufficient to meet the
demands for real-time performance. Meanwhile, the optimization of CPU
usage with af_packet is quite significant. Use hrtimer instead of timer
to help compensate for the shortcomings in real-time performance.
In HZ=100 or HZ=250 system, the update of TP_STATUS_USER is not real-time
enough, with fluctuations reaching over 8ms (on a system with HZ=250).
This is unacceptable in some high real-time systems that require timely
processing of network packets. By replacing it with hrtimer, if a timeout
of 2ms is set, the update of TP_STATUS_USER can be stabilized to within
3 ms.
Delete delete_blk_timer field, because hrtimer_cancel will check and wait
until the timer callback return and ensure never enter callback again.
Simplify the logic related to setting timeout, only update the hrtimer
expire time within the hrtimer callback, no longer update the expire time
in prb_open_block which is called by tpacket_rcv or timer callback.
Reasons why NOT update hrtimer in prb_open_block:
1) It will increase complexity to distinguish the two caller scenario.
2) hrtimer_cancel and hrtimer_start need to be called if you want to update
TMO of an already enqueued hrtimer, leading to complex shutdown logic.
One side effect of NOT update hrtimer when called by tpacket_rcv is that
a newly opened block triggered by tpacket_rcv may be retired earlier than
expected. On the other hand, if timeout is updated in prb_open_block, the
frequent reception of network packets that leads to prb_open_block being
called may cause hrtimer to be removed and enqueued repeatedly.
The retire hrtimer expiration is unconditional and periodic. If there are
numerous packet sockets on the system, please set an appropriate timeout
to avoid frequent enqueueing of hrtimers.
Reviewed-by: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
Reviewed-by: Jason Xing <kerneljasonxing@gmail.com>
Link: https://lore.kernel.org/all/20250831100822.1238795-1-jackzxcui1989@163.com/
Signed-off-by: Xin Zhao <jackzxcui1989@163.com>
Link: https://patch.msgid.link/20250908104549.204412-3-jackzxcui1989@163.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
kactive_blk_num (K) is only incremented on block close.
In timer callback prb_retire_rx_blk_timer_expired, except delete_blk_timer
is true, last_kactive_blk_num (L) is set to match kactive_blk_num (K) in
all cases. L is also set to match K in prb_open_block.
The only case K not equal to L is when scheduled by tpacket_rcv
and K is just incremented on block close but no new block could be opened,
so that it does not call prb_open_block in prb_dispatch_next_block.
This patch modifies the prb_retire_rx_blk_timer_expired function by simply
removing the check for L == K. This patch just provides another checkpoint
to thaw the might-be-frozen block in any case. It doesn't have any effect
because __packet_lookup_frame_in_block() has the same logic and does it
again without this patch when detecting the ring is frozen. The patch only
advances checking the status of the ring.
Suggested-by: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
Reviewed-by: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
Reviewed-by: Jason Xing <kerneljasonxing@gmail.com>
Link: https://lore.kernel.org/all/20250831100822.1238795-1-jackzxcui1989@163.com/
Signed-off-by: Xin Zhao <jackzxcui1989@163.com>
Link: https://patch.msgid.link/20250908104549.204412-2-jackzxcui1989@163.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When packet_set_ring() releases po->bind_lock, another thread can
run packet_notifier() and process an NETDEV_UP event.
This race and the fix are both similar to that of commit 15fe076ede
("net/packet: fix a race in packet_bind() and packet_notifier()").
There too the packet_notifier NETDEV_UP event managed to run while a
po->bind_lock critical section had to be temporarily released. And
the fix was similarly to temporarily set po->num to zero to keep
the socket unhooked until the lock is retaken.
The po->bind_lock in packet_set_ring and packet_notifier precede the
introduction of git history.
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Signed-off-by: Quang Le <quanglex97@gmail.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20250801175423.2970334-1-willemdebruijn.kernel@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When MSG_DONTWAIT is not set, the tpacket_snd operation will wait for
pending_refcnt to decrement to zero before returning. The pending_refcnt
is decremented by 1 when the skb->destructor function is called,
indicating that the skb has been successfully sent and needs to be
destroyed.
If an error occurs during this process, the tpacket_snd() function will
exit and return error, but pending_refcnt may not yet have decremented to
zero. Assuming the next send operation is executed immediately, but there
are no available frames to be sent in tx_ring (i.e., packet_current_frame
returns NULL), and skb is also NULL, the function will not execute
wait_for_completion_interruptible_timeout() to yield the CPU. Instead, it
will enter a do-while loop, waiting for pending_refcnt to be zero. Even
if the previous skb has completed transmission, the skb->destructor
function can only be invoked in the ksoftirqd thread (assuming NAPI
threading is enabled). When both the ksoftirqd thread and the tpacket_snd
operation happen to run on the same CPU, and the CPU trapped in the
do-while loop without yielding, the ksoftirqd thread will not get
scheduled to run. As a result, pending_refcnt will never be reduced to
zero, and the do-while loop cannot exit, eventually leading to a CPU soft
lockup issue.
In fact, skb is true for all but the first iterations of that loop, and
as long as pending_refcnt is not zero, even if incremented by a previous
call, wait_for_completion_interruptible_timeout() should be executed to
yield the CPU, allowing the ksoftirqd thread to be scheduled. Therefore,
the execution condition of this function should be modified to check if
pending_refcnt is not zero, instead of check skb.
- if (need_wait && skb) {
+ if (need_wait && packet_read_pending(&po->tx_ring)) {
As a result, the judgment conditions are duplicated with the end code of
the while loop, and packet_read_pending() is a very expensive function.
Actually, this loop can only exit when ph is NULL, so the loop condition
can be changed to while (1), and in the "ph = NULL" branch, if the
subsequent condition of if is not met, the loop can break directly. Now,
the loop logic remains the same as origin but is clearer and more obvious.
Fixes: 89ed5b5190 ("af_packet: Block execution of tasks waiting for transmit to complete in AF_PACKET")
Cc: stable@kernel.org
Suggested-by: LongJun Tang <tanglongjun@kylinos.cn>
Signed-off-by: Yun Lu <luyun@kylinos.cn>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Due to the changes in commit 581073f626 ("af_packet: do not call
packet_read_pending() from tpacket_destruct_skb()"), every time
tpacket_destruct_skb() is executed, the skb_completion is marked as
completed. When wait_for_completion_interruptible_timeout() returns
completed, the pending_refcnt has not yet been reduced to zero.
Therefore, when ph is NULL, the wait function may need to be called
multiple times until packet_read_pending() finally returns zero.
We should call sock_sndtimeo() only once, otherwise the SO_SNDTIMEO
constraint could be way off.
Fixes: 581073f626 ("af_packet: do not call packet_read_pending() from tpacket_destruct_skb()")
Cc: stable@kernel.org
Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Yun Lu <luyun@kylinos.cn>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Difference between sock_i_uid() and sk_uid() is that
after sock_orphan(), sock_i_uid() returns GLOBAL_ROOT_UID
while sk_uid() returns the last cached sk->sk_uid value.
None of sock_i_uid() callers care about this.
Use sk_uid() which is much faster and inlined.
Note that diag/dump users are calling sock_i_ino() and
can not see the full benefit yet.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Lorenzo Colitti <lorenzo@google.com>
Reviewed-by: Maciej Żenczykowski <maze@google.com>
Link: https://patch.msgid.link/20250620133001.4090592-3-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Syzkaller reports the following issue:
BUG: sleeping function called from invalid context at kernel/locking/mutex.c:578
__mutex_lock+0x106/0xe80 kernel/locking/mutex.c:746
team_change_rx_flags+0x38/0x220 drivers/net/team/team_core.c:1781
dev_change_rx_flags net/core/dev.c:9145 [inline]
__dev_set_promiscuity+0x3f8/0x590 net/core/dev.c:9189
netif_set_promiscuity+0x50/0xe0 net/core/dev.c:9201
dev_set_promiscuity+0x126/0x260 net/core/dev_api.c:286 packet_dev_mc net/packet/af_packet.c:3698 [inline]
packet_dev_mclist_delete net/packet/af_packet.c:3722 [inline]
packet_notifier+0x292/0xa60 net/packet/af_packet.c:4247
notifier_call_chain+0x1b3/0x3e0 kernel/notifier.c:85
call_netdevice_notifiers_extack net/core/dev.c:2214 [inline]
call_netdevice_notifiers net/core/dev.c:2228 [inline]
unregister_netdevice_many_notify+0x15d8/0x2330 net/core/dev.c:11972
rtnl_delete_link net/core/rtnetlink.c:3522 [inline]
rtnl_dellink+0x488/0x710 net/core/rtnetlink.c:3564
rtnetlink_rcv_msg+0x7cf/0xb70 net/core/rtnetlink.c:6955
netlink_rcv_skb+0x219/0x490 net/netlink/af_netlink.c:2534
Calling `PACKET_ADD_MEMBERSHIP` on an ops-locked device can trigger
the `NETDEV_UNREGISTER` notifier, which may require disabling promiscuous
and/or allmulti mode. Both of these operations require acquiring
the netdev instance lock.
Move the call to `packet_dev_mc` outside of the RCU critical section.
The `mclist` modifications (add, del, flush, unregister) are protected by
the RTNL, not the RCU. The RCU only protects the `sklist` and its
associated `sks`. The delayed operation on the `mclist` entry remains
within the RTNL.
Reported-by: syzbot+b191b5ccad8d7a986286@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=b191b5ccad8d7a986286
Fixes: ad7c7b2172 ("net: hold netdev instance lock during sysfs operations")
Signed-off-by: Stanislav Fomichev <stfomichev@gmail.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20250522031129.3247266-1-stfomichev@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
timer_delete[_sync]() replaces del_timer[_sync](). Convert the whole tree
over and remove the historical wrapper inlines.
Conversion was done with coccinelle plus manual fixups where necessary.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Avoid open coding initialization of sockcm fields.
Avoid reading the sk_priority field twice.
This ensures all callers, existing and future, will correctly try a
cmsg passed mark before sk_mark.
This patch extends support for cmsg mark to:
packet_spkt and packet_tpacket and net/can/raw.c.
This patch extends support for cmsg priority to:
packet_spkt and packet_tpacket.
Signed-off-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20250214222720.3205500-3-willemdebruijn.kernel@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The Linux socket API currently allows setting SO_PRIORITY at the
socket level, applying a uniform priority to all packets sent through
that socket. The exception to this is IP_TOS, when the priority value
is calculated during the handling of
ancillary data, as implemented in commit f02db315b8 ("ipv4: IP_TOS
and IP_TTL can be specified as ancillary data").
However, this is a computed
value, and there is currently no mechanism to set a custom priority
via control messages prior to this patch.
According to this patch, if SO_PRIORITY is specified as ancillary data,
the packet is sent with the priority value set through
sockc->priority, overriding the socket-level values
set via the traditional setsockopt() method. This is analogous to
the existing support for SO_MARK, as implemented in
commit c6af0c227a ("ip: support SO_MARK cmsg").
If both cmsg SO_PRIORITY and IP_TOS are passed, then the one that
takes precedence is the last one in the cmsg list.
This patch has the side effect that raw_send_hdrinc now interprets cmsg
IP_TOS.
Reviewed-by: Willem de Bruijn <willemb@google.com>
Suggested-by: Ferenc Fejes <fejes@inf.elte.hu>
Signed-off-by: Anna Emese Nyiri <annaemesenyiri@gmail.com>
Link: https://patch.msgid.link/20241213084457.45120-3-annaemesenyiri@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
PACKET socket can retain its fanout membership through link down and up
and leave a fanout while closed regardless of link state.
However, socket was forbidden from joining a fanout while it was not
RUNNING.
This patch allows PACKET socket to join fanout while not RUNNING.
Socket can be RUNNING if it has a specified protocol. Either directly
from packet_create (being implicitly bound to any interface) or following
a successful bind. Socket RUNNING state is switched off if it is bound to
an interface that went down.
Instead of the test for RUNNING, this patch adds a test that socket can
become RUNNING.
Signed-off-by: Gur Stavi <gur.stavi@huawei.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/4f1a3c37dbef980ef044c4d2adf91c76e2eca14b.1728802323.git.gur.stavi@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The last type of sockets which supports SOF_TIMESTAMPING_OPT_ID is RAW
sockets. To add new option this patch converts all callers (direct and
indirect) of _sock_tx_timestamp to provide sockcm_cookie instead of
tsflags. And while here fix __sock_tx_timestamp to receive tsflags as
__u32 instead of __u16.
Reviewed-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Jason Xing <kerneljasonxing@gmail.com>
Signed-off-by: Vadim Fedorenko <vadfed@meta.com>
Link: https://patch.msgid.link/20241001125716.2832769-3-vadfed@meta.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
For device memory TCP, we expect the skb headers to be available in host
memory for access, and we expect the skb frags to be in device memory
and unaccessible to the host. We expect there to be no mixing and
matching of device memory frags (unaccessible) with host memory frags
(accessible) in the same skb.
Add a skb->devmem flag which indicates whether the frags in this skb
are device memory frags or not.
__skb_fill_netmem_desc() now checks frags added to skbs for net_iov,
and marks the skb as skb->devmem accordingly.
Add checks through the network stack to avoid accessing the frags of
devmem skbs and avoid coalescing devmem skbs with non devmem skbs.
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com>
Signed-off-by: Mina Almasry <almasrymina@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Link: https://patch.msgid.link/20240910171458.219195-9-almasrymina@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The issue initially stems from libpcap. The ethertype will be overwritten
as the VLAN TPID if the network interface lacks hardware VLAN offloading.
In the outbound packet path, if hardware VLAN offloading is unavailable,
the VLAN tag is inserted into the payload but then cleared from the sk_buff
struct. Consequently, this can lead to a false negative when checking for
the presence of a VLAN tag, causing the packet sniffing outcome to lack
VLAN tag information (i.e., TCI-TPID). As a result, the packet capturing
tool may be unable to parse packets as expected.
The TCI-TPID is missing because the prb_fill_vlan_info() function does not
modify the tp_vlan_tci/tp_vlan_tpid values, as the information is in the
payload and not in the sk_buff struct. The skb_vlan_tag_present() function
only checks vlan_all in the sk_buff struct. In cooked mode, the L2 header
is stripped, preventing the packet capturing tool from determining the
correct TCI-TPID value. Additionally, the protocol in SLL is incorrect,
which means the packet capturing tool cannot parse the L3 header correctly.
Link: https://github.com/the-tcpdump-group/libpcap/issues/1105
Link: https://lore.kernel.org/netdev/20240520070348.26725-1-chengen.du@canonical.com/T/#u
Fixes: 393e52e33c ("packet: deliver VLAN TCI to userspace")
Cc: stable@vger.kernel.org
Signed-off-by: Chengen Du <chengen.du@canonical.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20240713114735.62360-1-chengen.du@canonical.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Kees Cook
Xin Zhao
Eric Dumazet
Quang Le
Jakub Kicinski
Yun Lu
Ingo Molnar
Stanislav Fomichev
Thomas Gleixner
Willem de Bruijn
Anna Emese Nyiri
Ignat Korchagin
Gur Stavi
Vadim Fedorenko
Mina Almasry
Chengen Du
Yan Zhai