user/sven/linux.git/include/linux/socket.h, branch v5.4.224

net: make get_net_ns return error if NET_NS is disabled

2021-06-23T12:41:25Z

[ Upstream commit ea6932d70e223e02fea3ae20a4feff05d7c1ea9a ] There is a panic in socket ioctl cmd SIOCGSKNS when NET_NS is not enabled. The reason is that nsfs tries to access ns->ops but the proc_ns_operations is not implemented in this case. [7.670023] Unable to handle kernel NULL pointer dereference at virtual address 00000010 [7.670268] pgd = 32b54000 [7.670544] [00000010] *pgd=00000000 [7.671861] Internal error: Oops: 5 [#1] SMP ARM [7.672315] Modules linked in: [7.672918] CPU: 0 PID: 1 Comm: systemd Not tainted 5.13.0-rc3-00375-g6799d4f2da49 #16 [7.673309] Hardware name: Generic DT based system [7.673642] PC is at nsfs_evict+0x24/0x30 [7.674486] LR is at clear_inode+0x20/0x9c The same to tun SIOCGSKNS command. To fix this problem, we make get_net_ns() return -EINVAL when NET_NS is disabled. Meanwhile move it to right place net/core/net_namespace.c. Signed-off-by: Changbin Du Fixes: c62cce2caee5 ("net: add an ioctl to get a socket network namespace") Cc: Cong Wang Cc: Jakub Kicinski Cc: David Laight Cc: Christian Brauner Suggested-by: Jakub Kicinski Acked-by: Christian Brauner Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

net: increase SOMAXCONN to 4096

2019-10-31T21:01:40Z

SOMAXCONN is /proc/sys/net/core/somaxconn default value. It has been defined as 128 more than 20 years ago. Since it caps the listen() backlog values, the very small value has caused numerous problems over the years, and many people had to raise it on their hosts after beeing hit by problems. Google has been using 1024 for at least 15 years, and we increased this to 4096 after TCP listener rework has been completed, more than 4 years ago. We got no complain of this change breaking any legacy application. Many applications indeed setup a TCP listener with listen(fd, -1); meaning they let the system select the backlog. Raising SOMAXCONN lowers chance of the port being unavailable under even small SYNFLOOD attack, and reduces possibilities of side channel vulnerabilities. Signed-off-by: Eric Dumazet Cc: Willy Tarreau Cc: Yue Cao Signed-off-by: David S. Miller

net/tls: prevent skb_orphan() from leaking TLS plain text with offload

2019-08-09T05:39:35Z

sk_validate_xmit_skb() and drivers depend on the sk member of struct sk_buff to identify segments requiring encryption. Any operation which removes or does not preserve the original TLS socket such as skb_orphan() or skb_clone() will cause clear text leaks. Make the TCP socket underlying an offloaded TLS connection mark all skbs as decrypted, if TLS TX is in offload mode. Then in sk_validate_xmit_skb() catch skbs which have no socket (or a socket with no validation) and decrypted flag set. Note that CONFIG_SOCK_VALIDATE_XMIT, CONFIG_TLS_DEVICE and sk->sk_validate_xmit_skb are slightly interchangeable right now, they all imply TLS offload. The new checks are guarded by CONFIG_TLS_DEVICE because that's the option guarding the sk_buff->decrypted member. Second, smaller issue with orphaning is that it breaks the guarantee that packets will be delivered to device queues in-order. All TLS offload drivers depend on that scheduling property. This means skb_orphan_partial()'s trick of preserving partial socket references will cause issues in the drivers. We need a full orphan, and as a result netem delay/throttling will cause all TLS offload skbs to be dropped. Reusing the sk_buff->decrypted flag also protects from leaking clear text when incoming, decrypted skb is redirected (e.g. by TC). See commit 0608c69c9a80 ("bpf: sk_msg, sock{map|hash} redirect through ULP") for justification why the internal flag is safe. The only location which could leak the flag in is tcp_bpf_sendmsg(), which is taken care of by clearing the previously unused bit. v2: - remove superfluous decrypted mark copy (Willem); - remove the stale doc entry (Boris); - rely entirely on EOR marking to prevent coalescing (Boris); - use an internal sendpages flag instead of marking the socket (Boris). v3 (Willem): - reorganize the can_skb_orphan_partial() condition; - fix the flag leak-in through tcp_bpf_sendmsg. Signed-off-by: Jakub Kicinski Acked-by: Willem de Bruijn Reviewed-by: Boris Pismenny Signed-off-by: David S. Miller

io_uring: add support for recvmsg()

2019-07-09T20:32:14Z

This is done through IORING_OP_RECVMSG. This opcode uses the same sqe->msg_flags that IORING_OP_SENDMSG added, and we pass in the msghdr struct in the sqe->addr field as well. We use MSG_DONTWAIT to force an inline fast path if recvmsg() doesn't block, and punt to async execution if it would have. Acked-by: David S. Miller Signed-off-by: Jens Axboe

io_uring: add support for sendmsg()

2019-07-09T20:32:05Z

This is done through IORING_OP_SENDMSG. There's a new sqe->msg_flags for the flags argument, and the msghdr struct is passed in the sqe->addr field. We use MSG_DONTWAIT to force an inline fast path if sendmsg() doesn't block, and punt to async execution if it would have. Acked-by: David S. Miller Signed-off-by: Jens Axboe

net: add documentation to socket.c

2019-03-15T22:29:47Z

Adds missing sphinx documentation to the socket.c's functions. Also fixes some whitespaces. I also changed the style of older documentation as an effort to have an uniform documentation style. Signed-off-by: Pedro Tammela Signed-off-by: David S. Miller

socket: Add SO_TIMESTAMPING_NEW

2019-02-03T19:17:31Z

Add SO_TIMESTAMPING_NEW variant of socket timestamp options. This is the y2038 safe versions of the SO_TIMESTAMPING_OLD for all architectures. Signed-off-by: Deepa Dinamani Acked-by: Willem de Bruijn Cc: chris@zankel.net Cc: fenghua.yu@intel.com Cc: rth@twiddle.net Cc: tglx@linutronix.de Cc: ubraun@linux.ibm.com Cc: linux-alpha@vger.kernel.org Cc: linux-arch@vger.kernel.org Cc: linux-ia64@vger.kernel.org Cc: linux-mips@linux-mips.org Cc: linux-s390@vger.kernel.org Cc: linux-xtensa@linux-xtensa.org Cc: sparclinux@vger.kernel.org Signed-off-by: David S. Miller

Merge tag 'y2038-for-4.21' of ssh://gitolite.kernel.org:/pub/scm/linux/kernel/git/arnd/playground

2018-12-28T20:45:04Z

Pull y2038 updates from Arnd Bergmann: "More syscalls and cleanups This concludes the main part of the system call rework for 64-bit time_t, which has spread over most of year 2018, the last six system calls being - ppoll - pselect6 - io_pgetevents - recvmmsg - futex - rt_sigtimedwait As before, nothing changes for 64-bit architectures, while 32-bit architectures gain another entry point that differs only in the layout of the timespec structure. Hopefully in the next release we can wire up all 22 of those system calls on all 32-bit architectures, which gives us a baseline version for glibc to start using them. This does not include the clock_adjtime, getrusage/waitid, and getitimer/setitimer system calls. I still plan to have new versions of those as well, but they are not required for correct operation of the C library since they can be emulated using the old 32-bit time_t based system calls. Aside from the system calls, there are also a few cleanups here, removing old kernel internal interfaces that have become unused after all references got removed. The arch/sh cleanups are part of this, there were posted several times over the past year without a reaction from the maintainers, while the corresponding changes made it into all other architectures" * tag 'y2038-for-4.21' of ssh://gitolite.kernel.org:/pub/scm/linux/kernel/git/arnd/playground: timekeeping: remove obsolete time accessors vfs: replace current_kernel_time64 with ktime equivalent timekeeping: remove timespec_add/timespec_del timekeeping: remove unused {read,update}_persistent_clock sh: remove board_time_init() callback sh: remove unused rtc_sh_get/set_time infrastructure sh: sh03: rtc: push down rtc class ops into driver sh: dreamcast: rtc: push down rtc class ops into driver y2038: signal: Add compat_sys_rt_sigtimedwait_time64 y2038: signal: Add sys_rt_sigtimedwait_time32 y2038: socket: Add compat_sys_recvmmsg_time64 y2038: futex: Add support for __kernel_timespec y2038: futex: Move compat implementation into futex.c io_pgetevents: use __kernel_timespec pselect6: use __kernel_timespec ppoll: use __kernel_timespec signal: Add restore_user_sigmask() signal: Add set_user_sigmask()

bpf: sk_msg, sock{map|hash} redirect through ULP

2018-12-20T22:47:09Z

A sockmap program that redirects through a kTLS ULP enabled socket will not work correctly because the ULP layer is skipped. This fixes the behavior to call through the ULP layer on redirect to ensure any operations required on the data stream at the ULP layer continue to be applied. To do this we add an internal flag MSG_SENDPAGE_NOPOLICY to avoid calling the BPF layer on a redirected message. This is required to avoid calling the BPF layer multiple times (possibly recursively) which is not the current/expected behavior without ULPs. In the future we may add a redirect flag if users _do_ want the policy applied again but this would need to work for both ULP and non-ULP sockets and be opt-in to avoid breaking existing programs. Also to avoid polluting the flag space with an internal flag we reuse the flag space overlapping MSG_SENDPAGE_NOPOLICY with MSG_WAITFORONE. Here WAITFORONE is specific to recv path and SENDPAGE_NOPOLICY is only used for sendpage hooks. The last thing to verify is user space API is masked correctly to ensure the flag can not be set by user. (Note this needs to be true regardless because we have internal flags already in-use that user space should not be able to set). But for completeness we have two UAPI paths into sendpage, sendfile and splice. In the sendfile case the function do_sendfile() zero's flags, ./fs/read_write.c: static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos, size_t count, loff_t max) { ... fl = 0; #if 0 /* * We need to debate whether we can enable this or not. The * man page documents EAGAIN return for the output at least, * and the application is arguably buggy if it doesn't expect * EAGAIN on a non-blocking file descriptor. */ if (in.file->f_flags & O_NONBLOCK) fl = SPLICE_F_NONBLOCK; #endif file_start_write(out.file); retval = do_splice_direct(in.file, &pos, out.file, &out_pos, count, fl); } In the splice case the pipe_to_sendpage "actor" is used which masks flags with SPLICE_F_MORE. ./fs/splice.c: static int pipe_to_sendpage(struct pipe_inode_info *pipe, struct pipe_buffer *buf, struct splice_desc *sd) { ... more = (sd->flags & SPLICE_F_MORE) ? MSG_MORE : 0; ... } Confirming what we expect that internal flags are in fact internal to socket side. Fixes: d3b18ad31f93 ("tls: add bpf support to sk_msg handling") Signed-off-by: John Fastabend Signed-off-by: Daniel Borkmann

y2038: socket: Add compat_sys_recvmmsg_time64

2018-12-18T15:13:04Z

recvmmsg() takes two arguments to pointers of structures that differ between 32-bit and 64-bit architectures: mmsghdr and timespec. For y2038 compatbility, we are changing the native system call from timespec to __kernel_timespec with a 64-bit time_t (in another patch), and use the existing compat system call on both 32-bit and 64-bit architectures for compatibility with traditional 32-bit user space. As we now have two variants of recvmmsg() for 32-bit tasks that are both different from the variant that we use on 64-bit tasks, this means we also require two compat system calls! The solution I picked is to flip things around: The existing compat_sys_recvmmsg() call gets moved from net/compat.c into net/socket.c and now handles the case for old user space on all architectures that have set CONFIG_COMPAT_32BIT_TIME. A new compat_sys_recvmmsg_time64() call gets added in the old place for 64-bit architectures only, this one handles the case of a compat mmsghdr structure combined with __kernel_timespec. In the indirect sys_socketcall(), we now need to call either do_sys_recvmmsg() or __compat_sys_recvmmsg(), depending on what kind of architecture we are on. For compat_sys_socketcall(), no such change is needed, we always call __compat_sys_recvmmsg(). I decided to not add a new SYS_RECVMMSG_TIME64 socketcall: Any libc implementation for 64-bit time_t will need significant changes including an updated asm/unistd.h, and it seems better to consistently use the separate syscalls that configuration, leaving the socketcall only for backward compatibility with 32-bit time_t based libc. The naming is asymmetric for the moment, so both existing syscalls entry points keep their names, while the new ones are recvmmsg_time32 and compat_recvmmsg_time64 respectively. I expect that we will rename the compat syscalls later as we start using generated syscall tables everywhere and add these entry points. Signed-off-by: Arnd Bergmann