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2017-08-21Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-4/+1
2017-08-18datagram: When peeking datagrams with offset < 0 don't skip empty skbsMatthew Dawson1-4/+1
Due to commit e6afc8ace6dd5cef5e812f26c72579da8806f5ac ("udp: remove headers from UDP packets before queueing"), when udp packets are being peeked the requested extra offset is always 0 as there is no need to skip the udp header. However, when the offset is 0 and the next skb is of length 0, it is only returned once. The behaviour can be seen with the following python script: from socket import *; f=socket(AF_INET6, SOCK_DGRAM | SOCK_NONBLOCK, 0); g=socket(AF_INET6, SOCK_DGRAM | SOCK_NONBLOCK, 0); f.bind(('::', 0)); addr=('::1', f.getsockname()[1]); g.sendto(b'', addr) g.sendto(b'b', addr) print(f.recvfrom(10, MSG_PEEK)); print(f.recvfrom(10, MSG_PEEK)); Where the expected output should be the empty string twice. Instead, make sk_peek_offset return negative values, and pass those values to __skb_try_recv_datagram/__skb_try_recv_from_queue. If the passed offset to __skb_try_recv_from_queue is negative, the checked skb is never skipped. __skb_try_recv_from_queue will then ensure the offset is reset back to 0 if a peek is requested without an offset, unless no packets are found. Also simplify the if condition in __skb_try_recv_from_queue. If _off is greater then 0, and off is greater then or equal to skb->len, then (_off || skb->len) must always be true assuming skb->len >= 0 is always true. Also remove a redundant check around a call to sk_peek_offset in af_unix.c, as it double checked if MSG_PEEK was set in the flags. V2: - Moved the negative fixup into __skb_try_recv_from_queue, and remove now redundant checks - Fix peeking in udp{,v6}_recvmsg to report the right value when the offset is 0 V3: - Marked new branch in __skb_try_recv_from_queue as unlikely. Signed-off-by: Matthew Dawson <matthew@mjdsystems.ca> Acked-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-17net/unix: drop obsolete fd-recursion limitsDavid Herrmann1-23/+1
All unix sockets now account inflight FDs to the respective sender. This was introduced in: commit 712f4aad406bb1ed67f3f98d04c044191f0ff593 Author: willy tarreau <w@1wt.eu> Date: Sun Jan 10 07:54:56 2016 +0100 unix: properly account for FDs passed over unix sockets and further refined in: commit 415e3d3e90ce9e18727e8843ae343eda5a58fad6 Author: Hannes Frederic Sowa <hannes@stressinduktion.org> Date: Wed Feb 3 02:11:03 2016 +0100 unix: correctly track in-flight fds in sending process user_struct Hence, regardless of the stacking depth of FDs, the total number of inflight FDs is limited, and accounted. There is no known way for a local user to exceed those limits or exploit the accounting. Furthermore, the GC logic is independent of the recursion/stacking depth as well. It solely depends on the total number of inflight FDs, regardless of their layout. Lastly, the current `recursion_level' suffers a TOCTOU race, since it checks and inherits depths only at queue time. If we consider `A<-B' to mean `queue-B-on-A', the following sequence circumvents the recursion level easily: A<-B B<-C C<-D ... Y<-Z resulting in: A<-B<-C<-...<-Z With all of this in mind, lets drop the recursion limit. It has no additional security value, anymore. On the contrary, it randomly confuses message brokers that try to forward file-descriptors, since any sendmsg(2) call can fail spuriously with ETOOMANYREFS if a client maliciously modifies the FD while inflight. Cc: Alban Crequy <alban.crequy@collabora.co.uk> Cc: Simon McVittie <simon.mcvittie@collabora.co.uk> Signed-off-by: David Herrmann <dh.herrmann@gmail.com> Reviewed-by: Tom Gundersen <teg@jklm.no> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-05Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-nextLinus Torvalds1-8/+8
Pull networking updates from David Miller: "Reasonably busy this cycle, but perhaps not as busy as in the 4.12 merge window: 1) Several optimizations for UDP processing under high load from Paolo Abeni. 2) Support pacing internally in TCP when using the sch_fq packet scheduler for this is not practical. From Eric Dumazet. 3) Support mutliple filter chains per qdisc, from Jiri Pirko. 4) Move to 1ms TCP timestamp clock, from Eric Dumazet. 5) Add batch dequeueing to vhost_net, from Jason Wang. 6) Flesh out more completely SCTP checksum offload support, from Davide Caratti. 7) More plumbing of extended netlink ACKs, from David Ahern, Pablo Neira Ayuso, and Matthias Schiffer. 8) Add devlink support to nfp driver, from Simon Horman. 9) Add RTM_F_FIB_MATCH flag to RTM_GETROUTE queries, from Roopa Prabhu. 10) Add stack depth tracking to BPF verifier and use this information in the various eBPF JITs. From Alexei Starovoitov. 11) Support XDP on qed device VFs, from Yuval Mintz. 12) Introduce BPF PROG ID for better introspection of installed BPF programs. From Martin KaFai Lau. 13) Add bpf_set_hash helper for TC bpf programs, from Daniel Borkmann. 14) For loads, allow narrower accesses in bpf verifier checking, from Yonghong Song. 15) Support MIPS in the BPF selftests and samples infrastructure, the MIPS eBPF JIT will be merged in via the MIPS GIT tree. From David Daney. 16) Support kernel based TLS, from Dave Watson and others. 17) Remove completely DST garbage collection, from Wei Wang. 18) Allow installing TCP MD5 rules using prefixes, from Ivan Delalande. 19) Add XDP support to Intel i40e driver, from Björn Töpel 20) Add support for TC flower offload in nfp driver, from Simon Horman, Pieter Jansen van Vuuren, Benjamin LaHaise, Jakub Kicinski, and Bert van Leeuwen. 21) IPSEC offloading support in mlx5, from Ilan Tayari. 22) Add HW PTP support to macb driver, from Rafal Ozieblo. 23) Networking refcount_t conversions, From Elena Reshetova. 24) Add sock_ops support to BPF, from Lawrence Brako. This is useful for tuning the TCP sockopt settings of a group of applications, currently via CGROUPs" * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1899 commits) net: phy: dp83867: add workaround for incorrect RX_CTRL pin strap dt-bindings: phy: dp83867: provide a workaround for incorrect RX_CTRL pin strap cxgb4: Support for get_ts_info ethtool method cxgb4: Add PTP Hardware Clock (PHC) support cxgb4: time stamping interface for PTP nfp: default to chained metadata prepend format nfp: remove legacy MAC address lookup nfp: improve order of interfaces in breakout mode net: macb: remove extraneous return when MACB_EXT_DESC is defined bpf: add missing break in for the TCP_BPF_SNDCWND_CLAMP case bpf: fix return in load_bpf_file mpls: fix rtm policy in mpls_getroute net, ax25: convert ax25_cb.refcount from atomic_t to refcount_t net, ax25: convert ax25_route.refcount from atomic_t to refcount_t net, ax25: convert ax25_uid_assoc.refcount from atomic_t to refcount_t net, sctp: convert sctp_ep_common.refcnt from atomic_t to refcount_t net, sctp: convert sctp_transport.refcnt from atomic_t to refcount_t net, sctp: convert sctp_chunk.refcnt from atomic_t to refcount_t net, sctp: convert sctp_datamsg.refcnt from atomic_t to refcount_t net, sctp: convert sctp_auth_bytes.refcnt from atomic_t to refcount_t ...
2017-07-01net: convert unix_address.refcnt from atomic_t to refcount_tReshetova, Elena1-4/+4
refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David Windsor <dwindsor@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-01net: convert sock.sk_refcnt from atomic_t to refcount_tReshetova, Elena1-1/+1
refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. This patch uses refcount_inc_not_zero() instead of atomic_inc_not_zero_hint() due to absense of a _hint() version of refcount API. If the hint() version must be used, we might need to revisit API. Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David Windsor <dwindsor@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-01net: convert sock.sk_wmem_alloc from atomic_t to refcount_tReshetova, Elena1-3/+3
refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David Windsor <dwindsor@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-20sched/wait: Rename wait_queue_t => wait_queue_entry_tIngo Molnar1-2/+2
Rename: wait_queue_t => wait_queue_entry_t 'wait_queue_t' was always a slight misnomer: its name implies that it's a "queue", but in reality it's a queue *entry*. The 'real' queue is the wait queue head, which had to carry the name. Start sorting this out by renaming it to 'wait_queue_entry_t'. This also allows the real structure name 'struct __wait_queue' to lose its double underscore and become 'struct wait_queue_entry', which is the more canonical nomenclature for such data types. Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-09af_unix: Add sockaddr length checks before accessing sa_family in bind and ↵Mateusz Jurczyk1-1/+6
connect handlers Verify that the caller-provided sockaddr structure is large enough to contain the sa_family field, before accessing it in bind() and connect() handlers of the AF_UNIX socket. Since neither syscall enforces a minimum size of the corresponding memory region, very short sockaddrs (zero or one byte long) result in operating on uninitialized memory while referencing .sa_family. Signed-off-by: Mateusz Jurczyk <mjurczyk@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-06af_unix: Use designated initializersKees Cook1-1/+1
Prepare to mark sensitive kernel structures for randomization by making sure they're using designated initializers. These were identified during allyesconfig builds of x86, arm, and arm64, and the initializer fixes were extracted from grsecurity. In this case, NULL initialize with { } instead of undesignated NULLs. Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-21net: unix: properly re-increment inflight counter of GC discarded candidatesAndrey Ulanov1-8/+9
Dmitry has reported that a BUG_ON() condition in unix_notinflight() may be triggered by a simple code that forwards unix socket in an SCM_RIGHTS message. That is caused by incorrect unix socket GC implementation in unix_gc(). The GC first collects list of candidates, then (a) decrements their "children's" inflight counter, (b) checks which inflight counters are now 0, and then (c) increments all inflight counters back. (a) and (c) are done by calling scan_children() with inc_inflight or dec_inflight as the second argument. Commit 6209344f5a37 ("net: unix: fix inflight counting bug in garbage collector") changed scan_children() such that it no longer considers sockets that do not have UNIX_GC_CANDIDATE flag. It also added a block of code that that unsets this flag _before_ invoking scan_children(, dec_iflight, ). This may lead to incorrect inflight counters for some sockets. This change fixes this bug by changing order of operations: UNIX_GC_CANDIDATE is now unset only after all inflight counters are restored to the original state. kernel BUG at net/unix/garbage.c:149! RIP: 0010:[<ffffffff8717ebf4>] [<ffffffff8717ebf4>] unix_notinflight+0x3b4/0x490 net/unix/garbage.c:149 Call Trace: [<ffffffff8716cfbf>] unix_detach_fds.isra.19+0xff/0x170 net/unix/af_unix.c:1487 [<ffffffff8716f6a9>] unix_destruct_scm+0xf9/0x210 net/unix/af_unix.c:1496 [<ffffffff86a90a01>] skb_release_head_state+0x101/0x200 net/core/skbuff.c:655 [<ffffffff86a9808a>] skb_release_all+0x1a/0x60 net/core/skbuff.c:668 [<ffffffff86a980ea>] __kfree_skb+0x1a/0x30 net/core/skbuff.c:684 [<ffffffff86a98284>] kfree_skb+0x184/0x570 net/core/skbuff.c:705 [<ffffffff871789d5>] unix_release_sock+0x5b5/0xbd0 net/unix/af_unix.c:559 [<ffffffff87179039>] unix_release+0x49/0x90 net/unix/af_unix.c:836 [<ffffffff86a694b2>] sock_release+0x92/0x1f0 net/socket.c:570 [<ffffffff86a6962b>] sock_close+0x1b/0x20 net/socket.c:1017 [<ffffffff81a76b8e>] __fput+0x34e/0x910 fs/file_table.c:208 [<ffffffff81a771da>] ____fput+0x1a/0x20 fs/file_table.c:244 [<ffffffff81483ab0>] task_work_run+0x1a0/0x280 kernel/task_work.c:116 [< inline >] exit_task_work include/linux/task_work.h:21 [<ffffffff8141287a>] do_exit+0x183a/0x2640 kernel/exit.c:828 [<ffffffff8141383e>] do_group_exit+0x14e/0x420 kernel/exit.c:931 [<ffffffff814429d3>] get_signal+0x663/0x1880 kernel/signal.c:2307 [<ffffffff81239b45>] do_signal+0xc5/0x2190 arch/x86/kernel/signal.c:807 [<ffffffff8100666a>] exit_to_usermode_loop+0x1ea/0x2d0 arch/x86/entry/common.c:156 [< inline >] prepare_exit_to_usermode arch/x86/entry/common.c:190 [<ffffffff81009693>] syscall_return_slowpath+0x4d3/0x570 arch/x86/entry/common.c:259 [<ffffffff881478e6>] entry_SYSCALL_64_fastpath+0xc4/0xc6 Link: https://lkml.org/lkml/2017/3/6/252 Signed-off-by: Andrey Ulanov <andreyu@google.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Fixes: 6209344 ("net: unix: fix inflight counting bug in garbage collector") Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-09net: Work around lockdep limitation in sockets that use socketsDavid Howells1-2/+3
Lockdep issues a circular dependency warning when AFS issues an operation through AF_RXRPC from a context in which the VFS/VM holds the mmap_sem. The theory lockdep comes up with is as follows: (1) If the pagefault handler decides it needs to read pages from AFS, it calls AFS with mmap_sem held and AFS begins an AF_RXRPC call, but creating a call requires the socket lock: mmap_sem must be taken before sk_lock-AF_RXRPC (2) afs_open_socket() opens an AF_RXRPC socket and binds it. rxrpc_bind() binds the underlying UDP socket whilst holding its socket lock. inet_bind() takes its own socket lock: sk_lock-AF_RXRPC must be taken before sk_lock-AF_INET (3) Reading from a TCP socket into a userspace buffer might cause a fault and thus cause the kernel to take the mmap_sem, but the TCP socket is locked whilst doing this: sk_lock-AF_INET must be taken before mmap_sem However, lockdep's theory is wrong in this instance because it deals only with lock classes and not individual locks. The AF_INET lock in (2) isn't really equivalent to the AF_INET lock in (3) as the former deals with a socket entirely internal to the kernel that never sees userspace. This is a limitation in the design of lockdep. Fix the general case by: (1) Double up all the locking keys used in sockets so that one set are used if the socket is created by userspace and the other set is used if the socket is created by the kernel. (2) Store the kern parameter passed to sk_alloc() in a variable in the sock struct (sk_kern_sock). This informs sock_lock_init(), sock_init_data() and sk_clone_lock() as to the lock keys to be used. Note that the child created by sk_clone_lock() inherits the parent's kern setting. (3) Add a 'kern' parameter to ->accept() that is analogous to the one passed in to ->create() that distinguishes whether kernel_accept() or sys_accept4() was the caller and can be passed to sk_alloc(). Note that a lot of accept functions merely dequeue an already allocated socket. I haven't touched these as the new socket already exists before we get the parameter. Note also that there are a couple of places where I've made the accepted socket unconditionally kernel-based: irda_accept() rds_rcp_accept_one() tcp_accept_from_sock() because they follow a sock_create_kern() and accept off of that. Whilst creating this, I noticed that lustre and ocfs don't create sockets through sock_create_kern() and thus they aren't marked as for-kernel, though they appear to be internal. I wonder if these should do that so that they use the new set of lock keys. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-02sched/headers: Prepare for new header dependencies before moving code to ↵Ingo Molnar1-1/+1
<linux/sched/signal.h> We are going to split <linux/sched/signal.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/signal.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-02-02unix: add ioctl to open a unix socket file with O_PATHAndrey Vagin1-0/+41
This ioctl opens a file to which a socket is bound and returns a file descriptor. The caller has to have CAP_NET_ADMIN in the socket network namespace. Currently it is impossible to get a path and a mount point for a socket file. socket_diag reports address, device ID and inode number for unix sockets. An address can contain a relative path or a file may be moved somewhere. And these properties say nothing about a mount namespace and a mount point of a socket file. With the introduced ioctl, we can get a path by reading /proc/self/fd/X and get mnt_id from /proc/self/fdinfo/X. In CRIU we are going to use this ioctl to dump and restore unix socket. Here is an example how it can be used: $ strace -e socket,bind,ioctl ./test /tmp/test_sock socket(AF_UNIX, SOCK_STREAM, 0) = 3 bind(3, {sa_family=AF_UNIX, sun_path="test_sock"}, 11) = 0 ioctl(3, SIOCUNIXFILE, 0) = 4 ^Z $ ss -a | grep test_sock u_str LISTEN 0 1 test_sock 17798 * 0 $ ls -l /proc/760/fd/{3,4} lrwx------ 1 root root 64 Feb 1 09:41 3 -> 'socket:[17798]' l--------- 1 root root 64 Feb 1 09:41 4 -> /tmp/test_sock $ cat /proc/760/fdinfo/4 pos: 0 flags: 012000000 mnt_id: 40 $ cat /proc/self/mountinfo | grep "^40\s" 40 19 0:37 / /tmp rw shared:23 - tmpfs tmpfs rw Signed-off-by: Andrei Vagin <avagin@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-24af_unix: move unix_mknod() out of bindlockWANG Cong1-11/+16
Dmitry reported a deadlock scenario: unix_bind() path: u->bindlock ==> sb_writer do_splice() path: sb_writer ==> pipe->mutex ==> u->bindlock In the unix_bind() code path, unix_mknod() does not have to be done with u->bindlock held, since it is a pure fs operation, so we can just move unix_mknod() out. Reported-by: Dmitry Vyukov <dvyukov@google.com> Tested-by: Dmitry Vyukov <dvyukov@google.com> Cc: Rainer Weikusat <rweikusat@mobileactivedefense.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-24Replace <asm/uaccess.h> with <linux/uaccess.h> globallyLinus Torvalds1-1/+1
This was entirely automated, using the script by Al: PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>' sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \ $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h) to do the replacement at the end of the merge window. Requested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-16Merge branch 'overlayfs-linus' of ↵Linus Torvalds1-3/+3
git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs Pull overlayfs updates from Miklos Szeredi: "This update contains: - try to clone on copy-up - allow renaming a directory - split source into managable chunks - misc cleanups and fixes It does not contain the read-only fd data inconsistency fix, which Al didn't like. I'll leave that to the next year..." * 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs: (36 commits) ovl: fix reStructuredText syntax errors in documentation ovl: fix return value of ovl_fill_super ovl: clean up kstat usage ovl: fold ovl_copy_up_truncate() into ovl_copy_up() ovl: create directories inside merged parent opaque ovl: opaque cleanup ovl: show redirect_dir mount option ovl: allow setting max size of redirect ovl: allow redirect_dir to default to "on" ovl: check for emptiness of redirect dir ovl: redirect on rename-dir ovl: lookup redirects ovl: consolidate lookup for underlying layers ovl: fix nested overlayfs mount ovl: check namelen ovl: split super.c ovl: use d_is_dir() ovl: simplify lookup ovl: check lower existence of rename target ovl: rename: simplify handling of lower/merged directory ...
2016-12-16Revert "af_unix: fix hard linked sockets on overlay"Miklos Szeredi1-3/+3
This reverts commit eb0a4a47ae89aaa0674ab3180de6a162f3be2ddf. Since commit 51f7e52dc943 ("ovl: share inode for hard link") there's no need to call d_real_inode() to check two overlay inodes for equality. Side effect of this revert is that it's no longer possible to connect one socket on overlayfs to one on the underlying layer (something which didn't make sense anyway). Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-11-22Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-6/+11
All conflicts were simple overlapping changes except perhaps for the Thunder driver. That driver has a change_mtu method explicitly for sending a message to the hardware. If that fails it returns an error. Normally a driver doesn't need an ndo_change_mtu method becuase those are usually just range changes, which are now handled generically. But since this extra operation is needed in the Thunder driver, it has to stay. However, if the message send fails we have to restore the original MTU before the change because the entire call chain expects that if an error is thrown by ndo_change_mtu then the MTU did not change. Therefore code is added to nicvf_change_mtu to remember the original MTU, and to restore it upon nicvf_update_hw_max_frs() failue. Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-18af_unix: conditionally use freezable blocking calls in readWANG Cong1-6/+11
Commit 2b15af6f95 ("af_unix: use freezable blocking calls in read") converts schedule_timeout() to its freezable version, it was probably correct at that time, but later, commit 2b514574f7e8 ("net: af_unix: implement splice for stream af_unix sockets") breaks the strong requirement for a freezable sleep, according to commit 0f9548ca1091: We shouldn't try_to_freeze if locks are held. Holding a lock can cause a deadlock if the lock is later acquired in the suspend or hibernate path (e.g. by dpm). Holding a lock can also cause a deadlock in the case of cgroup_freezer if a lock is held inside a frozen cgroup that is later acquired by a process outside that group. The pipe_lock is still held at that point. So use freezable version only for the recvmsg call path, avoid impact for Android. Fixes: 2b514574f7e8 ("net: af_unix: implement splice for stream af_unix sockets") Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Colin Cross <ccross@android.com> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-15Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-1/+2
Several cases of bug fixes in 'net' overlapping other changes in 'net-next-. Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-07udp: do fwd memory scheduling on dequeuePaolo Abeni1-2/+2
A new argument is added to __skb_recv_datagram to provide an explicit skb destructor, invoked under the receive queue lock. The UDP protocol uses such argument to perform memory reclaiming on dequeue, so that the UDP protocol does not set anymore skb->desctructor. Instead explicit memory reclaiming is performed at close() time and when skbs are removed from the receive queue. The in kernel UDP protocol users now need to call a skb_recv_udp() variant instead of skb_recv_datagram() to properly perform memory accounting on dequeue. Overall, this allows acquiring only once the receive queue lock on dequeue. Tested using pktgen with random src port, 64 bytes packet, wire-speed on a 10G link as sender and udp_sink as the receiver, using an l4 tuple rxhash to stress the contention, and one or more udp_sink instances with reuseport. nr sinks vanilla patched 1 440 560 3 2150 2300 6 3650 3800 9 4450 4600 12 6250 6450 v1 -> v2: - do rmem and allocated memory scheduling under the receive lock - do bulk scheduling in first_packet_length() and in udp_destruct_sock() - avoid the typdef for the dequeue callback Suggested-by: Eric Dumazet <edumazet@google.com> Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-01unix: escape all null bytes in abstract unix domain socketIsaac Boukris1-1/+2
Abstract unix domain socket may embed null characters, these should be translated to '@' when printed out to proc the same way the null prefix is currently being translated. This helps for tools such as netstat, lsof and the proc based implementation in ss to show all the significant bytes of the name (instead of getting cut at the first null occurrence). Signed-off-by: Isaac Boukris <iboukris@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-03skb_splice_bits(): get rid of callbackAl Viro1-16/+1
since pipe_lock is the outermost now, we don't need to drop/regain socket locks around the call of splice_to_pipe() from skb_splice_bits(), which kills the need to have a socket-specific callback; we can just call splice_to_pipe() and be done with that. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-09-04af_unix: split 'u->readlock' into two: 'iolock' and 'bindlock'Linus Torvalds1-22/+23
Right now we use the 'readlock' both for protecting some of the af_unix IO path and for making the bind be single-threaded. The two are independent, but using the same lock makes for a nasty deadlock due to ordering with regards to filesystem locking. The bind locking would want to nest outside the VSF pathname locking, but the IO locking wants to nest inside some of those same locks. We tried to fix this earlier with commit c845acb324aa ("af_unix: Fix splice-bind deadlock") which moved the readlock inside the vfs locks, but that caused problems with overlayfs that will then call back into filesystem routines that take the lock in the wrong order anyway. Splitting the locks means that we can go back to having the bind lock be the outermost lock, and we don't have any deadlocks with lock ordering. Acked-by: Rainer Weikusat <rweikusat@cyberadapt.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-04Revert "af_unix: Fix splice-bind deadlock"Linus Torvalds1-40/+26
This reverts commit c845acb324aa85a39650a14e7696982ceea75dc1. It turns out that it just replaces one deadlock with another one: we can still get the wrong lock ordering with the readlock due to overlayfs calling back into the filesystem layer and still taking the vfs locks after the readlock. The proper solution ends up being to just split the readlock into two pieces: the bind lock (taken *outside* the vfs locks) and the IO lock (taken *inside* the filesystem locks). The two locks are independent anyway. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Reviewed-by: Shmulik Ladkani <shmulik.ladkani@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-26af_unix: charge buffers to kmemcgVladimir Davydov1-0/+1
Unix sockets can consume a significant amount of system memory, hence they should be accounted to kmemcg. Since unix socket buffers are always allocated from process context, all we need to do to charge them to kmemcg is set __GFP_ACCOUNT in sock->sk_allocation mask. Eric asked: > 1) What happens when a buffer, allocated from socket <A> lands in a > different socket <B>, maybe owned by another user/process. > > Who owns it now, in term of kmemcg accounting ? We never move memcg charges. E.g. if two processes from different cgroups are sharing a memory region, each page will be charged to the process which touched it first. Or if two processes are working with the same directory tree, inodes and dentries will be charged to the first user. The same is fair for unix socket buffers - they will be charged to the sender. > 2) Has performance impact been evaluated ? I ran netperf STREAM_STREAM with default options in a kmemcg on a 4 core x2 HT box. The results are below: # clients bandwidth (10^6bits/sec) base patched 1 67643 +- 725 64874 +- 353 - 4.0 % 4 193585 +- 2516 186715 +- 1460 - 3.5 % 8 194820 +- 377 187443 +- 1229 - 3.7 % So the accounting doesn't come for free - it takes ~4% of performance. I believe we could optimize it by using per cpu batching not only on charge, but also on uncharge in memcg core, but that's beyond the scope of this patch set - I'll take a look at this later. Anyway, if performance impact is found to be unacceptable, it is always possible to disable kmem accounting at boot time (cgroup.memory=nokmem) or not use memory cgroups at runtime at all (thanks to jump labels there'll be no overhead even if they are compiled in). Link: http://lkml.kernel.org/r/fcfe6cae27a59fbc5e40145664b3cf085a560c68.1464079538.git.vdavydov@virtuozzo.com Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-06-12Merge branch 'overlayfs-af_unix-fix' into overlayfs-linusMiklos Szeredi1-3/+3
2016-05-20af_unix: fix hard linked sockets on overlayMiklos Szeredi1-3/+3
Overlayfs uses separate inodes even in the case of hard links on the underlying filesystems. This is a problem for AF_UNIX socket implementation which indexes sockets based on the inode. This resulted in hard linked sockets not working. The fix is to use the real, underlying inode. Test case follows: -- ovl-sock-test.c -- #include <unistd.h> #include <err.h> #include <sys/socket.h> #include <sys/un.h> #define SOCK "test-sock" #define SOCK2 "test-sock2" int main(void) { int fd, fd2; struct sockaddr_un addr = { .sun_family = AF_UNIX, .sun_path = SOCK, }; struct sockaddr_un addr2 = { .sun_family = AF_UNIX, .sun_path = SOCK2, }; unlink(SOCK); unlink(SOCK2); if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) == -1) err(1, "socket"); if (bind(fd, (struct sockaddr *) &addr, sizeof(addr)) == -1) err(1, "bind"); if (listen(fd, 0) == -1) err(1, "listen"); if (link(SOCK, SOCK2) == -1) err(1, "link"); if ((fd2 = socket(AF_UNIX, SOCK_STREAM, 0)) == -1) err(1, "socket"); if (connect(fd2, (struct sockaddr *) &addr2, sizeof(addr2)) == -1) err (1, "connect"); return 0; } ---- Reported-by: Alexander Morozov <alexandr.morozov@docker.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Cc: <stable@vger.kernel.org>
2016-03-28constify security_path_{mkdir,mknod,symlink}Al Viro1-1/+1
... as well as unix_mknod() and may_o_create() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-02-23Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller3-15/+25
Conflicts: drivers/net/phy/bcm7xxx.c drivers/net/phy/marvell.c drivers/net/vxlan.c All three conflicts were cases of simple overlapping changes. Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-19af_unix: Don't use continue to re-execute unix_stream_read_generic loopRainer Weikusat1-1/+2
The unix_stream_read_generic function tries to use a continue statement to restart the receive loop after waiting for a message. This may not work as intended as the caller might use a recvmsg call to peek at control messages without specifying a message buffer. If this was the case, the continue will cause the function to return without an error and without the credential information if the function had to wait for a message while it had returned with the credentials otherwise. Change to using goto to restart the loop without checking the condition first in this case so that credentials are returned either way. Signed-off-by: Rainer Weikusat <rweikusat@mobileactivedefense.com> Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-19unix_diag: fix incorrect sign extension in unix_lookup_by_inoDmitry V. Levin1-1/+1
The value passed by unix_diag_get_exact to unix_lookup_by_ino has type __u32, but unix_lookup_by_ino's argument ino has type int, which is not a problem yet. However, when ino is compared with sock_i_ino return value of type unsigned long, ino is sign extended to signed long, and this results to incorrect comparison on 64-bit architectures for inode numbers greater than INT_MAX. This bug was found by strace test suite. Fixes: 5d3cae8bc39d ("unix_diag: Dumping exact socket core") Signed-off-by: Dmitry V. Levin <ldv@altlinux.org> Acked-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-16af_unix: Guard against other == sk in unix_dgram_sendmsgRainer Weikusat1-1/+6
The unix_dgram_sendmsg routine use the following test if (unlikely(unix_peer(other) != sk && unix_recvq_full(other))) { to determine if sk and other are in an n:1 association (either established via connect or by using sendto to send messages to an unrelated socket identified by address). This isn't correct as the specified address could have been bound to the sending socket itself or because this socket could have been connected to itself by the time of the unix_peer_get but disconnected before the unix_state_lock(other). In both cases, the if-block would be entered despite other == sk which might either block the sender unintentionally or lead to trying to unlock the same spin lock twice for a non-blocking send. Add a other != sk check to guard against this. Fixes: 7d267278a9ec ("unix: avoid use-after-free in ep_remove_wait_queue") Reported-By: Philipp Hahn <pmhahn@pmhahn.de> Signed-off-by: Rainer Weikusat <rweikusat@mobileactivedefense.com> Tested-by: Philipp Hahn <pmhahn@pmhahn.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-16af_unix: Don't set err in unix_stream_read_generic unless there was an errorRainer Weikusat1-6/+10
The present unix_stream_read_generic contains various code sequences of the form err = -EDISASTER; if (<test>) goto out; This has the unfortunate side effect of possibly causing the error code to bleed through to the final out: return copied ? : err; and then to be wrongly returned if no data was copied because the caller didn't supply a data buffer, as demonstrated by the program available at http://pad.lv/1540731 Change it such that err is only set if an error condition was detected. Fixes: 3822b5c2fc62 ("af_unix: Revert 'lock_interruptible' in stream receive code") Reported-by: Joseph Salisbury <joseph.salisbury@canonical.com> Signed-off-by: Rainer Weikusat <rweikusat@mobileactivedefense.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-08unix: correctly track in-flight fds in sending process user_structHannes Frederic Sowa2-6/+6
The commit referenced in the Fixes tag incorrectly accounted the number of in-flight fds over a unix domain socket to the original opener of the file-descriptor. This allows another process to arbitrary deplete the original file-openers resource limit for the maximum of open files. Instead the sending processes and its struct cred should be credited. To do so, we add a reference counted struct user_struct pointer to the scm_fp_list and use it to account for the number of inflight unix fds. Fixes: 712f4aad406bb1 ("unix: properly account for FDs passed over unix sockets") Reported-by: David Herrmann <dh.herrmann@gmail.com> Cc: David Herrmann <dh.herrmann@gmail.com> Cc: Willy Tarreau <w@1wt.eu> Cc: Linus Torvalds <torvalds@linux-foundation.org> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-07net: drop write-only stack variableDavid Herrmann1-4/+1
Remove a write-only stack variable from unix_attach_fds(). This is a left-over from the security fix in: commit 712f4aad406bb1ed67f3f98d04c044191f0ff593 Author: willy tarreau <w@1wt.eu> Date: Sun Jan 10 07:54:56 2016 +0100 unix: properly account for FDs passed over unix sockets Signed-off-by: David Herrmann <dh.herrmann@gmail.com> Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-01-24af_unix: fix struct pid memory leakEric Dumazet1-0/+1
Dmitry reported a struct pid leak detected by a syzkaller program. Bug happens in unix_stream_recvmsg() when we break the loop when a signal is pending, without properly releasing scm. Fixes: b3ca9b02b007 ("net: fix multithreaded signal handling in unix recv routines") Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Rainer Weikusat <rweikusat@mobileactivedefense.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-01-11Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller2-9/+28
Conflicts: drivers/net/bonding/bond_main.c drivers/net/ethernet/mellanox/mlxsw/spectrum.h drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c The bond_main.c and mellanox switch conflicts were cases of overlapping changes. Signed-off-by: David S. Miller <davem@davemloft.net>
2016-01-11unix: properly account for FDs passed over unix socketswilly tarreau2-9/+28
It is possible for a process to allocate and accumulate far more FDs than the process' limit by sending them over a unix socket then closing them to keep the process' fd count low. This change addresses this problem by keeping track of the number of FDs in flight per user and preventing non-privileged processes from having more FDs in flight than their configured FD limit. Reported-by: socketpair@gmail.com Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Mitigates: CVE-2013-4312 (Linux 2.0+) Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-01-06Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-26/+40
2016-01-04af_unix: Fix splice-bind deadlockRainer Weikusat1-26/+40
On 2015/11/06, Dmitry Vyukov reported a deadlock involving the splice system call and AF_UNIX sockets, http://lists.openwall.net/netdev/2015/11/06/24 The situation was analyzed as (a while ago) A: socketpair() B: splice() from a pipe to /mnt/regular_file does sb_start_write() on /mnt C: try to freeze /mnt wait for B to finish with /mnt A: bind() try to bind our socket to /mnt/new_socket_name lock our socket, see it not bound yet decide that it needs to create something in /mnt try to do sb_start_write() on /mnt, block (it's waiting for C). D: splice() from the same pipe to our socket lock the pipe, see that socket is connected try to lock the socket, block waiting for A B: get around to actually feeding a chunk from pipe to file, try to lock the pipe. Deadlock. on 2015/11/10 by Al Viro, http://lists.openwall.net/netdev/2015/11/10/4 The patch fixes this by removing the kern_path_create related code from unix_mknod and executing it as part of unix_bind prior acquiring the readlock of the socket in question. This means that A (as used above) will sb_start_write on /mnt before it acquires the readlock, hence, it won't indirectly block B which first did a sb_start_write and then waited for a thread trying to acquire the readlock. Consequently, A being blocked by C waiting for B won't cause a deadlock anymore (effectively, both A and B acquire two locks in opposite order in the situation described above). Dmitry Vyukov(<dvyukov@google.com>) tested the original patch. Signed-off-by: Rainer Weikusat <rweikusat@mobileactivedefense.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-17Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-10/+3
Conflicts: drivers/net/geneve.c Here we had an overlapping change, where in 'net' the extraneous stats bump was being removed whilst in 'net-next' the final argument to udp_tunnel6_xmit_skb() was being changed. Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-17af_unix: Revert 'lock_interruptible' in stream receive codeRainer Weikusat1-10/+3
With b3ca9b02b00704053a38bfe4c31dbbb9c13595d0, the AF_UNIX SOCK_STREAM receive code was changed from using mutex_lock(&u->readlock) to mutex_lock_interruptible(&u->readlock) to prevent signals from being delayed for an indefinite time if a thread sleeping on the mutex happened to be selected for handling the signal. But this was never a problem with the stream receive code (as opposed to its datagram counterpart) as that never went to sleep waiting for new messages with the mutex held and thus, wouldn't cause secondary readers to block on the mutex waiting for the sleeping primary reader. As the interruptible locking makes the code more complicated in exchange for no benefit, change it back to using mutex_lock. Signed-off-by: Rainer Weikusat <rweikusat@mobileactivedefense.com> Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-06af_unix: fix unix_dgram_recvmsg entry lockingRainer Weikusat1-15/+20
The current unix_dgram_recvsmg code acquires the u->readlock mutex in order to protect access to the peek offset prior to calling __skb_recv_datagram for actually receiving data. This implies that a blocking reader will go to sleep with this mutex held if there's presently no data to return to userspace. Two non-desirable side effects of this are that a later non-blocking read call on the same socket will block on the ->readlock mutex until the earlier blocking call releases it (or the readers is interrupted) and that later blocking read calls will wait longer than the effective socket read timeout says they should: The timeout will only start 'ticking' once such a reader hits the schedule_timeout in wait_for_more_packets (core.c) while the time it already had to wait until it could acquire the mutex is unaccounted for. The patch avoids both by using the __skb_try_recv_datagram and __skb_wait_for_more packets functions created by the first patch to implement a unix_dgram_recvmsg read loop which releases the readlock mutex prior to going to sleep and reacquires it as needed afterwards. Non-blocking readers will thus immediately return with -EAGAIN if there's no data available regardless of any concurrent blocking readers and all blocking readers will end up sleeping via schedule_timeout, thus honouring the configured socket receive timeout. Signed-off-by: Rainer Weikusat <rweikusat@mobileactivedefense.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-03Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-37/+231
Conflicts: drivers/net/ethernet/renesas/ravb_main.c kernel/bpf/syscall.c net/ipv4/ipmr.c All three conflicts were cases of overlapping changes. Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-01net: rename SOCK_ASYNC_NOSPACE and SOCK_ASYNC_WAITDATAEric Dumazet1-3/+3
This patch is a cleanup to make following patch easier to review. Goal is to move SOCK_ASYNC_NOSPACE and SOCK_ASYNC_WAITDATA from (struct socket)->flags to a (struct socket_wq)->flags to benefit from RCU protection in sock_wake_async() To ease backports, we rename both constants. Two new helpers, sk_set_bit(int nr, struct sock *sk) and sk_clear_bit(int net, struct sock *sk) are added so that following patch can change their implementation. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-01unix: use wq_has_sleeper in unix_dgram_recvmsgRainer Weikusat1-2/+4
The current unix_dgram_recvmsg does a wake up for every received datagram. This seems wasteful as only SOCK_DGRAM client sockets in an n:1 association with a server socket will ever wait because of the associated condition. The patch below changes the function such that the wake up only happens if wq_has_sleeper indicates that someone actually wants to be notified. Testing with SOCK_SEQPACKET and SOCK_DGRAM socket seems to confirm that this is an improvment. Signed-Off-By: Rainer Weikusat <rweikusat@mobileactivedefense.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-11-30af-unix: passcred support for sendpageHannes Frederic Sowa1-15/+64
sendpage did not care about credentials at all. This could lead to situations in which because of fd passing between processes we could append data to skbs with different scm data. It is illegal to splice those skbs together. Instead we have to allocate a new skb and if requested fill out the scm details. Fixes: 869e7c62486ec ("net: af_unix: implement stream sendpage support") Reported-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Eric Dumazet <edumazet@google.com> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-11-30net: Generalise wq_has_sleeper helperHerbert Xu1-1/+1
The memory barrier in the helper wq_has_sleeper is needed by just about every user of waitqueue_active. This patch generalises it by making it take a wait_queue_head_t directly. The existing helper is renamed to skwq_has_sleeper. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>