kernel/linux.git/net/socket.c, branch v6.1.176

net: guard timestamp cmsgs to real error queue skbs

2026-06-19T11:37:12+00:00

[ Upstream commit 1ee90b77b727df903033db873c75caac5c27ec98 ] skb_is_err_queue() treats PACKET_OUTGOING as the sole marker for an skb from sk_error_queue. That assumption is not true for AF_PACKET sockets: outgoing packet taps are also delivered to packet sockets with skb->pkt_type == PACKET_OUTGOING, but their skb->cb is owned by AF_PACKET instead of struct sock_exterr_skb. If such an skb is received with timestamping enabled, the generic timestamp cmsg path can read AF_PACKET control-buffer state as sock_exterr_skb::opt_stats. With SO_RXQ_OVFL enabled, the packet drop counter overlaps opt_stats. An odd drop count makes the path emit SCM_TIMESTAMPING_OPT_STATS with skb->len and skb->data. For non-linear skbs this copies past the linear head and can trigger hardened usercopy or disclose adjacent heap contents. Keep skb_is_err_queue() local to net/socket.c, but make it verify that the PACKET_OUTGOING marker is paired with the sock_rmem_free destructor installed by sock_queue_err_skb(). AF_PACKET receive skbs use normal receive ownership and no longer pass as error-queue skbs, while legitimate sk_error_queue entries keep the PACKET_OUTGOING marker and sock_rmem_free ownership. Fixes: 8605330aac5a ("tcp: fix SCM_TIMESTAMPING_OPT_STATS for normal skbs") Signed-off-by: Kyle Zeng Reviewed-by: Kuniyuki Iwashima Reviewed-by: Willem de Bruijn Link: https://patch.msgid.link/20260607021819.49698-1-kylebot@openai.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

net: Remove RTNL dance for SIOCBRADDIF and SIOCBRDELIF.

2026-01-11T14:19:23+00:00

commit ed3ba9b6e280e14cc3148c1b226ba453f02fa76c upstream. SIOCBRDELIF is passed to dev_ioctl() first and later forwarded to br_ioctl_call(), which causes unnecessary RTNL dance and the splat below [0] under RTNL pressure. Let's say Thread A is trying to detach a device from a bridge and Thread B is trying to remove the bridge. In dev_ioctl(), Thread A bumps the bridge device's refcnt by netdev_hold() and releases RTNL because the following br_ioctl_call() also re-acquires RTNL. In the race window, Thread B could acquire RTNL and try to remove the bridge device. Then, rtnl_unlock() by Thread B will release RTNL and wait for netdev_put() by Thread A. Thread A, however, must hold RTNL after the unlock in dev_ifsioc(), which may take long under RTNL pressure, resulting in the splat by Thread B. Thread A (SIOCBRDELIF) Thread B (SIOCBRDELBR) ---------------------- ---------------------- sock_ioctl sock_ioctl `- sock_do_ioctl `- br_ioctl_call `- dev_ioctl `- br_ioctl_stub |- rtnl_lock | |- dev_ifsioc ' ' |- dev = __dev_get_by_name(...) |- netdev_hold(dev, ...) . / |- rtnl_unlock ------. | | |- br_ioctl_call `---> |- rtnl_lock Race | | `- br_ioctl_stub |- br_del_bridge Window | | | |- dev = __dev_get_by_name(...) | | | May take long | `- br_dev_delete(dev, ...) | | | under RTNL pressure | `- unregister_netdevice_queue(dev, ...) | | | | `- rtnl_unlock \ | |- rtnl_lock <-' `- netdev_run_todo | |- ... `- netdev_run_todo | `- rtnl_unlock |- __rtnl_unlock | |- netdev_wait_allrefs_any |- netdev_put(dev, ...) <----------------' Wait refcnt decrement and log splat below To avoid blocking SIOCBRDELBR unnecessarily, let's not call dev_ioctl() for SIOCBRADDIF and SIOCBRDELIF. In the dev_ioctl() path, we do the following: 1. Copy struct ifreq by get_user_ifreq in sock_do_ioctl() 2. Check CAP_NET_ADMIN in dev_ioctl() 3. Call dev_load() in dev_ioctl() 4. Fetch the master dev from ifr.ifr_name in dev_ifsioc() 3. can be done by request_module() in br_ioctl_call(), so we move 1., 2., and 4. to br_ioctl_stub(). Note that 2. is also checked later in add_del_if(), but it's better performed before RTNL. SIOCBRADDIF and SIOCBRDELIF have been processed in dev_ioctl() since the pre-git era, and there seems to be no specific reason to process them there. [0]: unregister_netdevice: waiting for wpan3 to become free. Usage count = 2 ref_tracker: wpan3@ffff8880662d8608 has 1/1 users at __netdev_tracker_alloc include/linux/netdevice.h:4282 [inline] netdev_hold include/linux/netdevice.h:4311 [inline] dev_ifsioc+0xc6a/0x1160 net/core/dev_ioctl.c:624 dev_ioctl+0x255/0x10c0 net/core/dev_ioctl.c:826 sock_do_ioctl+0x1ca/0x260 net/socket.c:1213 sock_ioctl+0x23a/0x6c0 net/socket.c:1318 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl fs/ioctl.c:892 [inline] __x64_sys_ioctl+0x1a4/0x210 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcb/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Fixes: 893b19587534 ("net: bridge: fix ioctl locking") Reported-by: syzkaller Reported-by: yan kang Reported-by: yue sun Closes: https://lore.kernel.org/netdev/SY8P300MB0421225D54EB92762AE8F0F2A1D32@SY8P300MB0421.AUSP300.PROD.OUTLOOK.COM/ Signed-off-by: Kuniyuki Iwashima Acked-by: Stanislav Fomichev Reviewed-by: Ido Schimmel Acked-by: Nikolay Aleksandrov Link: https://patch.msgid.link/20250316192851.19781-1-kuniyu@amazon.com Signed-off-by: Paolo Abeni [cascardo: fixed conflict at dev_ifsioc] Signed-off-by: Thadeu Lima de Souza Cascardo Signed-off-by: Greg Kroah-Hartman

net: explicitly clear the sk pointer, when pf->create fails

2024-10-17T13:22:27+00:00

commit 631083143315d1b192bd7d915b967b37819e88ea upstream. We have recently noticed the exact same KASAN splat as in commit 6cd4a78d962b ("net: do not leave a dangling sk pointer, when socket creation fails"). The problem is that commit did not fully address the problem, as some pf->create implementations do not use sk_common_release in their error paths. For example, we can use the same reproducer as in the above commit, but changing ping to arping. arping uses AF_PACKET socket and if packet_create fails, it will just sk_free the allocated sk object. While we could chase all the pf->create implementations and make sure they NULL the freed sk object on error from the socket, we can't guarantee future protocols will not make the same mistake. So it is easier to just explicitly NULL the sk pointer upon return from pf->create in __sock_create. We do know that pf->create always releases the allocated sk object on error, so if the pointer is not NULL, it is definitely dangling. Fixes: 6cd4a78d962b ("net: do not leave a dangling sk pointer, when socket creation fails") Signed-off-by: Ignat Korchagin Cc: stable@vger.kernel.org Reviewed-by: Eric Dumazet Link: https://patch.msgid.link/20241003170151.69445-1-ignat@cloudflare.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

splice, net: Add a splice_eof op to file-ops and socket-ops

2024-01-10T16:10:27+00:00

[ Upstream commit 2bfc66850952b6921b2033b09729ec59eabbc81d ] Add an optional method, ->splice_eof(), to allow splice to indicate the premature termination of a splice to struct file_operations and struct proto_ops. This is called if sendfile() or splice() encounters all of the following conditions inside splice_direct_to_actor(): (1) the user did not set SPLICE_F_MORE (splice only), and (2) an EOF condition occurred (->splice_read() returned 0), and (3) we haven't read enough to fulfill the request (ie. len > 0 still), and (4) we have already spliced at least one byte. A further patch will modify the behaviour of SPLICE_F_MORE to always be passed to the actor if either the user set it or we haven't yet read sufficient data to fulfill the request. Suggested-by: Linus Torvalds Link: https://lore.kernel.org/r/CAHk-=wh=V579PDYvkpnTobCLGczbgxpMgGmmhqiTyE34Cpi5Gg@mail.gmail.com/ Signed-off-by: David Howells Reviewed-by: Jakub Kicinski cc: Jens Axboe cc: Christoph Hellwig cc: Al Viro cc: Matthew Wilcox cc: Jan Kara cc: Jeff Layton cc: David Hildenbrand cc: Christian Brauner cc: Chuck Lever cc: Boris Pismenny cc: John Fastabend cc: linux-mm@kvack.org Signed-off-by: Jakub Kicinski Stable-dep-of: a0002127cd74 ("udp: move udp->no_check6_tx to udp->udp_flags") Signed-off-by: Sasha Levin

net: Declare MSG_SPLICE_PAGES internal sendmsg() flag

2024-01-10T16:10:27+00:00

[ Upstream commit b841b901c452d92610f739a36e54978453528876 ] Declare MSG_SPLICE_PAGES, an internal sendmsg() flag, that hints to a network protocol that it should splice pages from the source iterator rather than copying the data if it can. This flag is added to a list that is cleared by sendmsg syscalls on entry. This is intended as a replacement for the ->sendpage() op, allowing a way to splice in several multipage folios in one go. Signed-off-by: David Howells Reviewed-by: Willem de Bruijn cc: Jens Axboe cc: Matthew Wilcox Signed-off-by: Jakub Kicinski Stable-dep-of: a0002127cd74 ("udp: move udp->no_check6_tx to udp->udp_flags") Signed-off-by: Sasha Levin

net: Save and restore msg_namelen in sock_sendmsg

2024-01-10T16:10:24+00:00

[ Upstream commit 01b2885d9415152bcb12ff1f7788f500a74ea0ed ] Commit 86a7e0b69bd5 ("net: prevent rewrite of msg_name in sock_sendmsg()") made sock_sendmsg save the incoming msg_name pointer and restore it before returning, to insulate the caller against msg_name being changed by the called code. If the address length was also changed however, we may return with an inconsistent structure where the length doesn't match the address, and attempts to reuse it may lead to lost packets. For example, a kernel that doesn't have commit 1c5950fc6fe9 ("udp6: fix potential access to stale information") will replace a v4 mapped address with its ipv4 equivalent, and shorten namelen accordingly from 28 to 16. If the caller attempts to reuse the resulting msg structure, it will have the original ipv6 (v4 mapped) address but an incorrect v4 length. Fixes: 86a7e0b69bd5 ("net: prevent rewrite of msg_name in sock_sendmsg()") Signed-off-by: Marc Dionne Reviewed-by: Willem de Bruijn Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

net: annotate data-races around sk->sk_bind_phc

2024-01-10T16:10:23+00:00

[ Upstream commit 251cd405a9e6e70b92fe5afbdd17fd5caf9d3266 ] sk->sk_bind_phc is read locklessly. Add corresponding annotations. Fixes: d463126e23f1 ("net: sock: extend SO_TIMESTAMPING for PHC binding") Signed-off-by: Eric Dumazet Cc: Yangbo Lu Signed-off-by: David S. Miller Stable-dep-of: 7f6ca95d16b9 ("net: Implement missing getsockopt(SO_TIMESTAMPING_NEW)") Signed-off-by: Sasha Levin

net: annotate data-races around sk->sk_tsflags

2024-01-10T16:10:23+00:00

[ Upstream commit e3390b30a5dfb112e8e802a59c0f68f947b638b2 ] sk->sk_tsflags can be read locklessly, add corresponding annotations. Fixes: b9f40e21ef42 ("net-timestamp: move timestamp flags out of sk_flags") Signed-off-by: Eric Dumazet Cc: Willem de Bruijn Signed-off-by: David S. Miller Stable-dep-of: 7f6ca95d16b9 ("net: Implement missing getsockopt(SO_TIMESTAMPING_NEW)") Signed-off-by: Sasha Levin

net: prevent address rewrite in kernel_bind()

2023-10-19T21:08:50+00:00

commit c889a99a21bf124c3db08d09df919f0eccc5ea4c upstream. Similar to the change in commit 0bdf399342c5("net: Avoid address overwrite in kernel_connect"), BPF hooks run on bind may rewrite the address passed to kernel_bind(). This change 1) Makes a copy of the bind address in kernel_bind() to insulate callers. 2) Replaces direct calls to sock->ops->bind() in net with kernel_bind() Link: https://lore.kernel.org/netdev/20230912013332.2048422-1-jrife@google.com/ Fixes: 4fbac77d2d09 ("bpf: Hooks for sys_bind") Cc: stable@vger.kernel.org Reviewed-by: Willem de Bruijn Signed-off-by: Jordan Rife Reviewed-by: Simon Horman Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: prevent rewrite of msg_name in sock_sendmsg()

2023-10-10T20:00:39+00:00

commit 86a7e0b69bd5b812e48a20c66c2161744f3caa16 upstream. Callers of sock_sendmsg(), and similarly kernel_sendmsg(), in kernel space may observe their value of msg_name change in cases where BPF sendmsg hooks rewrite the send address. This has been confirmed to break NFS mounts running in UDP mode and has the potential to break other systems. This patch: 1) Creates a new function called __sock_sendmsg() with same logic as the old sock_sendmsg() function. 2) Replaces calls to sock_sendmsg() made by __sys_sendto() and __sys_sendmsg() with __sock_sendmsg() to avoid an unnecessary copy, as these system calls are already protected. 3) Modifies sock_sendmsg() so that it makes a copy of msg_name if present before passing it down the stack to insulate callers from changes to the send address. Link: https://lore.kernel.org/netdev/20230912013332.2048422-1-jrife@google.com/ Fixes: 1cedee13d25a ("bpf: Hooks for sys_sendmsg") Cc: stable@vger.kernel.org Reviewed-by: Willem de Bruijn Signed-off-by: Jordan Rife Reviewed-by: Simon Horman Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman