kernel/linux.git/net/phonet, branch v5.15.209

phonet/pep: disable BH around forwarded sk_receive_skb()

2026-06-01T15:35:46+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()

2025-08-28T14:23:59+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/pep: fix racy skb_queue_empty() use

2025-05-02T05:44:18+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 [Harshit: backport to 5.15.y, clean cherrypick from 6.1.y commit] Signed-off-by: Harshit Mogalapalli Signed-off-by: Greg Kroah-Hartman

phonet: fix rtm_phonet_notify() skb allocation

2024-05-17T09:50:58+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: refcount leak in pep_sock_accep

2022-01-11T14:35:16+00:00

commit bcd0f93353326954817a4f9fa55ec57fb38acbb0 upstream. sock_hold(sk) is invoked in pep_sock_accept(), but __sock_put(sk) is not invoked in subsequent failure branches(pep_accept_conn() != 0). Signed-off-by: Hangyu Hua Link: https://lore.kernel.org/r/20211209082839.33985-1-hbh25y@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Aayush Agarwal Signed-off-by: Greg Kroah-Hartman

phonet/pep: refuse to enable an unbound pipe

2021-12-29T11:29:03+00:00

commit 75a2f31520095600f650597c0ac41f48b5ba0068 upstream. This ioctl() implicitly assumed that the socket was already bound to a valid local socket name, i.e. Phonet object. If the socket was not bound, two separate problems would occur: 1) We'd send an pipe enablement request with an invalid source object. 2) Later socket calls could BUG on the socket unexpectedly being connected yet not bound to a valid object. Reported-by: syzbot+2dc91e7fc3dea88b1e8a@syzkaller.appspotmail.com Signed-off-by: Rémi Denis-Courmont Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: Remove redundant if statements

2021-08-05T12:27:50+00:00

The 'if (dev)' statement already move into dev_{put , hold}, so remove redundant if statements. Signed-off-by: Yajun Deng Signed-off-by: David S. Miller

phonet: use siocdevprivate

2021-07-27T19:11:43+00:00

phonet has a single private ioctl that is broken in compat mode on big-endian machines today because the data returned from it is never copied back to user space. Move it over to the ndo_siocdevprivate callback, which also fixes the compat issue. Cc: Remi Denis-Courmont Signed-off-by: Arnd Bergmann Acked-by: Rémi Denis-Courmont Signed-off-by: David S. Miller

treewide: Use fallthrough pseudo-keyword

2020-08-23T22:36:59+00:00

Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva

net: pass a sockptr_t into ->setsockopt

2020-07-24T22:41:54+00:00

Rework the remaining setsockopt code to pass a sockptr_t instead of a plain user pointer. This removes the last remaining set_fs(KERNEL_DS) outside of architecture specific code. Signed-off-by: Christoph Hellwig Acked-by: Stefan Schmidt [ieee802154] Acked-by: Matthieu Baerts Signed-off-by: David S. Miller