kernel/linux.git/net/socket.c, branch v5.10.257

net: Save and restore msg_namelen in sock_sendmsg

2024-01-15T17:48:04+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: prevent address rewrite in kernel_bind()

2023-10-25T09:54:13+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()

2023-10-10T19:53:37+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

net: Avoid address overwrite in kernel_connect

2023-09-19T10:20:06+00:00

commit 0bdf399342c5acbd817c9098b6c7ed21f1974312 upstream. BPF programs that run on connect can rewrite the connect address. For the connect system call this isn't a problem, because a copy of the address is made when it is moved into kernel space. However, kernel_connect simply passes through the address it is given, so the caller may observe its address value unexpectedly change. A practical example where this is problematic is where NFS is combined with a system such as Cilium which implements BPF-based load balancing. A common pattern in software-defined storage systems is to have an NFS mount that connects to a persistent virtual IP which in turn maps to an ephemeral server IP. This is usually done to achieve high availability: if your server goes down you can quickly spin up a replacement and remap the virtual IP to that endpoint. With BPF-based load balancing, mounts will forget the virtual IP address when the address rewrite occurs because a pointer to the only copy of that address is passed down the stack. Server failover then breaks, because clients have forgotten the virtual IP address. Reconnects fail and mounts remain broken. This patch was tested by setting up a scenario like this and ensuring that NFS reconnects worked after applying the patch. Signed-off-by: Jordan Rife Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

bpf: Remove extra lock_sock for TCP_ZEROCOPY_RECEIVE

2023-07-27T06:43:37+00:00

[ Upstream commit 9cacf81f8161111db25f98e78a7a0e32ae142b3f ] Add custom implementation of getsockopt hook for TCP_ZEROCOPY_RECEIVE. We skip generic hooks for TCP_ZEROCOPY_RECEIVE and have a custom call in do_tcp_getsockopt using the on-stack data. This removes 3% overhead for locking/unlocking the socket. Without this patch: 3.38% 0.07% tcp_mmap [kernel.kallsyms] [k] __cgroup_bpf_run_filter_getsockopt | --3.30%--__cgroup_bpf_run_filter_getsockopt | --0.81%--__kmalloc With the patch applied: 0.52% 0.12% tcp_mmap [kernel.kallsyms] [k] __cgroup_bpf_run_filter_getsockopt_kern Note, exporting uapi/tcp.h requires removing netinet/tcp.h from test_progs.h because those headers have confliciting definitions. Signed-off-by: Stanislav Fomichev Signed-off-by: Alexei Starovoitov Acked-by: Martin KaFai Lau Link: https://lore.kernel.org/bpf/20210115163501.805133-2-sdf@google.com Stable-dep-of: 2598619e012c ("sctp: add bpf_bypass_getsockopt proto callback") Signed-off-by: Sasha Levin

net: annotate sk->sk_err write from do_recvmmsg()

2023-05-30T11:57:46+00:00

[ Upstream commit e05a5f510f26607616fecdd4ac136310c8bea56b ] do_recvmmsg() can write to sk->sk_err from multiple threads. As said before, many other points reading or writing sk_err need annotations. Fixes: 34b88a68f26a ("net: Fix use after free in the recvmmsg exit path") Signed-off-by: Eric Dumazet Reported-by: syzbot Reviewed-by: Kuniyuki Iwashima Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

net: remove cmsg restriction from io_uring based send/recvmsg calls

2023-01-04T10:39:24+00:00

[ Upstream commit e54937963fa249595824439dc839c948188dea83 ] No need to restrict these anymore, as the worker threads are direct clones of the original task. Hence we know for a fact that we can support anything that the regular task can. Since the only user of proto_ops->flags was to flag PROTO_CMSG_DATA_ONLY, kill the member and the flag definition too. Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

net: add accept helper not installing fd

2023-01-04T10:39:17+00:00

[ Upstream commit d32f89da7fa8ccc8b3fb8f909d61e42b9bc39329 ] Introduce and reuse a helper that acts similarly to __sys_accept4_file() but returns struct file instead of installing file descriptor. Will be used by io_uring. Signed-off-by: Pavel Begunkov Acked-by: Jakub Kicinski Signed-off-by: Jens Axboe Acked-by: David S. Miller Link: https://lore.kernel.org/r/c57b9e8e818d93683a3d24f8ca50ca038d1da8c4.1629888991.git.asml.silence@gmail.com Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

net: provide __sys_shutdown_sock() that takes a socket

2023-01-04T10:39:17+00:00

[ Upstream commit b713c195d59332277a31a59c91f755e53b5b302b ] No functional changes in this patch, needed to provide io_uring support for shutdown(2). Cc: netdev@vger.kernel.org Cc: David S. Miller Acked-by: Jakub Kicinski Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

net: Fix a data-race around sysctl_somaxconn.

2022-08-31T15:15:21+00:00

[ Upstream commit 3c9ba81d72047f2e81bb535d42856517b613aba7 ] While reading sysctl_somaxconn, it can be changed concurrently. Thus, we need to add READ_ONCE() to its reader. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima Signed-off-by: David S. Miller Signed-off-by: Sasha Levin