linux-stable.git/net/phonet, branch linux-6.1.y

net: phonet: free phonet_device after RCU grace period

2026-07-04T11:41:33+00:00

[ Upstream commit 71de0177b28da751f407581a4515cf4d762f6296 ]

phonet_device_destroy() removes a phonet_device from the per-net device
list with list_del_rcu(), but frees it immediately. RCU readers walking
the same list can still hold a pointer to the object after it has been
removed, leading to a slab-use-after-free.

Use kfree_rcu(), matching the lifetime rule already used by
phonet_address_del() for the same object type.

Fixes: eeb74a9d45f7 ("Phonet: convert devices list to RCU")
Cc: stable@vger.kernel.org
Signed-off-by: Santosh Kalluri 
Acked-by: Rémi Denis-Courmont 
Reviewed-by: Simon Horman 
Signed-off-by: Jakub Kicinski 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

phonet: Pass net and ifindex to phonet_address_notify().

2026-07-04T11:41:33+00:00

[ Upstream commit 68ed5c38b512b734caf3da1f87db4a99fcfe3002 ]

Currently, phonet_address_notify() fetches netns and ifindex from dev.

Once addr_doit() is converted to RCU, phonet_address_notify() will be
called outside of RCU due to GFP_KERNEL, and dev will be unavailable
there.

Let's pass net and ifindex to phonet_address_notify().

Signed-off-by: Kuniyuki Iwashima 
Reviewed-by: Eric Dumazet 
Signed-off-by: Paolo Abeni 
Stable-dep-of: 71de0177b28d ("net: phonet: free phonet_device after RCU grace period")
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

phonet: Pass ifindex to fill_addr().

2026-07-04T11:41:33+00:00

[ Upstream commit 08a9572be36819b5d9011604edfa5db6c5062a7a ]

We will convert addr_doit() and getaddr_dumpit() to RCU, both
of which call fill_addr().

The former will call phonet_address_notify() outside of RCU
due to GFP_KERNEL, so dev will not be available in fill_addr().

Let's pass ifindex directly to fill_addr().

Signed-off-by: Kuniyuki Iwashima 
Reviewed-by: Eric Dumazet 
Signed-off-by: Paolo Abeni 
Stable-dep-of: 71de0177b28d ("net: phonet: free phonet_device after RCU grace period")
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

phonet/pep: disable BH around forwarded sk_receive_skb()

2026-06-01T15:39:34+00:00

commit dbc81608e3a653dea6cf403f20cae35468b8ab9c upstream.

The networking receive path is usually run from softirq context, but
protocols that take the socket lock may have packets stored in the
backlog and processed later from process context. In that case
release_sock() -> __release_sock() drops the slock with spin_unlock_bh()
and then calls sk->sk_backlog_rcv() with bottom halves enabled.

Typical sk_backlog_rcv handlers process the socket whose backlog is
being drained, so the BH state at entry is irrelevant for the slocks
they touch. pep_do_rcv() is different: when the inbound skb targets an
existing PEP pipe, it forwards the skb to a different *child* socket
via sk_receive_skb(). That helper takes the child slock with
bh_lock_sock_nested(), which is just spin_lock_nested() and assumes BH
is already off. The same child slock therefore ends up acquired with
BH on (process path) and with BH off (softirq path):

  process context                   softirq context
  ---------------                   ---------------
  release_sock(listener)            __netif_receive_skb()
   __release_sock()                  phonet_rcv()
    spin_unlock_bh()                  __sk_receive_skb(listener)
    [BH now ENABLED]                  [BH already disabled]
    sk_backlog_rcv:                   sk_backlog_rcv:
     pep_do_rcv()                      pep_do_rcv()
      sk_receive_skb(child)             sk_receive_skb(child)
       bh_lock_sock_nested(child)        bh_lock_sock_nested(child)
       => SOFTIRQ-ON-W                   => IN-SOFTIRQ-W

Lockdep flags this as inconsistent lock state, and it can become a real
self-deadlock if a softirq on the same CPU tries to receive to the same
child socket while its slock is held in the BH-enabled path:

  WARNING: inconsistent lock state
  inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
   (slock-AF_PHONET/1){+.?.}-{3:3}, at: __sk_receive_skb+0x1cf/0x900
    __sk_receive_skb              net/core/sock.c:563
    sk_receive_skb                include/net/sock.h:2022 [inline]
    pep_do_rcv                    net/phonet/pep.c:675
    sk_backlog_rcv                include/net/sock.h:1190
    __release_sock                net/core/sock.c:3216
    release_sock                  net/core/sock.c:3815
    pep_sock_accept               net/phonet/pep.c:879

Wrap the forwarded sk_receive_skb() in local_bh_disable() /
local_bh_enable() so the child slock is always acquired with BH off.
local_bh_disable() nests safely on the softirq path.

Discovered via in-house syzkaller fuzzing; the same root cause also
on the linux-6.1.y syzbot dashboard as extid 44f0626dd6284f02663c.
Reproduced under KASAN + LOCKDEP + PROVE_LOCKING, reproducer:
https://pastebin.com/A3t8xzCR

Fixes: 9641458d3ec4 ("Phonet: Pipe End Point for Phonet Pipes protocol")
Link: https://syzkaller.appspot.com/bug?extid=44f0626dd6284f02663c
Cc: stable@vger.kernel.org
Signed-off-by: Zijing Yin 
Acked-by: Rémi Denis-Courmont 
Reported-by: syzbot+9f4a135646b66c509935@syzkaller.appspotmail.com
Reviewed-by: Eric Dumazet 
Link: https://patch.msgid.link/20260519172635.86304-1-yzjaurora@gmail.com
Signed-off-by: Jakub Kicinski 
Signed-off-by: Greg Kroah-Hartman

phonet/pep: Move call to pn_skb_get_dst_sockaddr() earlier in pep_sock_accept()

2025-07-24T06:51:48+00:00

commit 17ba793f381eb813596d6de1cc6820bcbda5ed8b upstream.

A new warning in clang [1] points out a place in pep_sock_accept() where
dst is uninitialized then passed as a const pointer to pep_find_pipe():

  net/phonet/pep.c:829:37: error: variable 'dst' is uninitialized when passed as a const pointer argument here [-Werror,-Wuninitialized-const-pointer]
    829 |         newsk = pep_find_pipe(&pn->hlist, &dst, pipe_handle);
        |                                            ^~~:

Move the call to pn_skb_get_dst_sockaddr(), which initializes dst, to
before the call to pep_find_pipe(), so that dst is consistently used
initialized throughout the function.

Cc: stable@vger.kernel.org
Fixes: f7ae8d59f661 ("Phonet: allocate sock from accept syscall rather than soft IRQ")
Link: https://github.com/llvm/llvm-project/commit/00dacf8c22f065cb52efb14cd091d441f19b319e [1]
Closes: https://github.com/ClangBuiltLinux/linux/issues/2101
Signed-off-by: Nathan Chancellor 
Link: https://patch.msgid.link/20250715-net-phonet-fix-uninit-const-pointer-v1-1-8efd1bd188b3@kernel.org
Signed-off-by: Jakub Kicinski 
Signed-off-by: Greg Kroah-Hartman

phonet: fix rtm_phonet_notify() skb allocation

2024-05-17T09:56:12+00:00

[ Upstream commit d8cac8568618dcb8a51af3db1103e8d4cc4aeea7 ]

fill_route() stores three components in the skb:

- struct rtmsg
- RTA_DST (u8)
- RTA_OIF (u32)

Therefore, rtm_phonet_notify() should use

NLMSG_ALIGN(sizeof(struct rtmsg)) +
nla_total_size(1) +
nla_total_size(4)

Fixes: f062f41d0657 ("Phonet: routing table Netlink interface")
Signed-off-by: Eric Dumazet 
Acked-by: Rémi Denis-Courmont 
Link: https://lore.kernel.org/r/20240502161700.1804476-1-edumazet@google.com
Signed-off-by: Jakub Kicinski 
Signed-off-by: Sasha Levin

phonet/pep: fix racy skb_queue_empty() use

2024-03-01T12:26:38+00:00

[ Upstream commit 7d2a894d7f487dcb894df023e9d3014cf5b93fe5 ]

The receive queues are protected by their respective spin-lock, not
the socket lock. This could lead to skb_peek() unexpectedly
returning NULL or a pointer to an already dequeued socket buffer.

Fixes: 9641458d3ec4 ("Phonet: Pipe End Point for Phonet Pipes protocol")
Signed-off-by: Rémi Denis-Courmont 
Link: https://lore.kernel.org/r/20240218081214.4806-2-remi@remlab.net
Signed-off-by: Paolo Abeni 
Signed-off-by: Sasha Levin

phonet: take correct lock to peek at the RX queue

2024-03-01T12:26:38+00:00

[ Upstream commit 3b2d9bc4d4acdf15a876eae2c0d83149250e85ba ]

The receive queue is protected by its embedded spin-lock, not the
socket lock, so we need the former lock here (and only that one).

Fixes: 107d0d9b8d9a ("Phonet: Phonet datagram transport protocol")
Reported-by: Luosili 
Signed-off-by: Rémi Denis-Courmont 
Reviewed-by: Eric Dumazet 
Link: https://lore.kernel.org/r/20240218081214.4806-1-remi@remlab.net
Signed-off-by: Paolo Abeni 
Signed-off-by: Sasha Levin

net: remove noblock parameter from recvmsg() entities

2022-04-12T13:00:25+00:00

The internal recvmsg() functions have two parameters 'flags' and 'noblock'
that were merged inside skb_recv_datagram(). As a follow up patch to commit
f4b41f062c42 ("net: remove noblock parameter from skb_recv_datagram()")
this patch removes the separate 'noblock' parameter for recvmsg().

Analogue to the referenced patch for skb_recv_datagram() the 'flags' and
'noblock' parameters are unnecessarily split up with e.g.

err = sk->sk_prot->recvmsg(sk, msg, size, flags & MSG_DONTWAIT,
                           flags & ~MSG_DONTWAIT, &addr_len);

or in

err = INDIRECT_CALL_2(sk->sk_prot->recvmsg, tcp_recvmsg, udp_recvmsg,
                      sk, msg, size, flags & MSG_DONTWAIT,
                      flags & ~MSG_DONTWAIT, &addr_len);

instead of simply using only flags all the time and check for MSG_DONTWAIT
where needed (to preserve for the formerly separated no(n)block condition).

Signed-off-by: Oliver Hartkopp 
Link: https://lore.kernel.org/r/20220411124955.154876-1-socketcan@hartkopp.net
Signed-off-by: Paolo Abeni

net: remove noblock parameter from skb_recv_datagram()

2022-04-06T12:45:26+00:00

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 
Signed-off-by: Oliver Hartkopp 
Signed-off-by: David S. Miller