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2021-11-26af_unix: Replace the big lock with small locks.Kuniyuki Iwashima1-1/+1
The hash table of AF_UNIX sockets is protected by the single lock. This patch replaces it with per-hash locks. The effect is noticeable when we handle multiple sockets simultaneously. Here is a test result on an EC2 c5.24xlarge instance. It shows latency (under 10us only) in unix_insert_unbound_socket() while 64 CPUs creating 1024 sockets for each in parallel. Without this patch: nsec : count distribution 0 : 179 | | 500 : 3021 |********* | 1000 : 6271 |******************* | 1500 : 6318 |******************* | 2000 : 5828 |***************** | 2500 : 5124 |*************** | 3000 : 4426 |************* | 3500 : 3672 |*********** | 4000 : 3138 |********* | 4500 : 2811 |******** | 5000 : 2384 |******* | 5500 : 2023 |****** | 6000 : 1954 |***** | 6500 : 1737 |***** | 7000 : 1749 |***** | 7500 : 1520 |**** | 8000 : 1469 |**** | 8500 : 1394 |**** | 9000 : 1232 |*** | 9500 : 1138 |*** | 10000 : 994 |*** | With this patch: nsec : count distribution 0 : 1634 |**** | 500 : 13170 |****************************************| 1000 : 13156 |*************************************** | 1500 : 9010 |*************************** | 2000 : 6363 |******************* | 2500 : 4443 |************* | 3000 : 3240 |********* | 3500 : 2549 |******* | 4000 : 1872 |***** | 4500 : 1504 |**** | 5000 : 1247 |*** | 5500 : 1035 |*** | 6000 : 889 |** | 6500 : 744 |** | 7000 : 634 |* | 7500 : 498 |* | 8000 : 433 |* | 8500 : 355 |* | 9000 : 336 |* | 9500 : 284 | | 10000 : 243 | | Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-11-26af_unix: Save hash in sk_hash.Kuniyuki Iwashima1-1/+0
To replace unix_table_lock with per-hash locks in the next patch, we need to save a hash in each socket because /proc/net/unix or BPF prog iterate sockets while holding a hash table lock and release it later in a different function. Currently, we store a real/pseudo hash in struct unix_address. However, we do not allocate it to unbound sockets, nor should we do just for that. For this purpose, we can use sk_hash. Then, we no longer use the hash field in struct unix_address and can remove it. Also, this patch does - rename unix_insert_socket() to unix_insert_unbound_socket() - remove the redundant list argument from __unix_insert_socket() and unix_insert_unbound_socket() - use 'unsigned int' instead of 'unsigned' in __unix_set_addr_hash() - remove 'inline' from unix_remove_socket() and unix_insert_unbound_socket(). Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-08-16af_unix: Add unix_stream_proto for sockmapJiang Wang1-2/+6
Previously, sockmap for AF_UNIX protocol only supports dgram type. This patch add unix stream type support, which is similar to unix_dgram_proto. To support sockmap, dgram and stream cannot share the same unix_proto anymore, because they have different implementations, such as unhash for stream type (which will remove closed or disconnected sockets from the map), so rename unix_proto to unix_dgram_proto and add a new unix_stream_proto. Also implement stream related sockmap functions. And add dgram key words to those dgram specific functions. Signed-off-by: Jiang Wang <jiang.wang@bytedance.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Reviewed-by: Cong Wang <cong.wang@bytedance.com> Acked-by: Jakub Sitnicki <jakub@cloudflare.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20210816190327.2739291-3-jiang.wang@bytedance.com
2021-08-04af_unix: Add OOB supportRao Shoaib1-0/+3
This patch adds OOB support for AF_UNIX sockets. The semantics is same as TCP. The last byte of a message with the OOB flag is treated as the OOB byte. The byte is separated into a skb and a pointer to the skb is stored in unix_sock. The pointer is used to enforce OOB semantics. Signed-off-by: Rao Shoaib <rao.shoaib@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-15af_unix: Implement unix_dgram_bpf_recvmsg()Cong Wang1-0/+2
We have to implement unix_dgram_bpf_recvmsg() to replace the original ->recvmsg() to retrieve skmsg from ingress_msg. AF_UNIX is again special here because the lack of sk_prot->recvmsg(). I simply add a special case inside unix_dgram_recvmsg() to call sk->sk_prot->recvmsg() directly. Signed-off-by: Cong Wang <cong.wang@bytedance.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210704190252.11866-8-xiyou.wangcong@gmail.com
2021-07-15af_unix: Implement ->psock_update_sk_prot()Cong Wang1-0/+10
Now we can implement unix_bpf_update_proto() to update sk_prot, especially prot->close(). Signed-off-by: Cong Wang <cong.wang@bytedance.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210704190252.11866-7-xiyou.wangcong@gmail.com
2020-02-28unix: uses an atomic type for scm files accountingPaolo Abeni1-1/+1
So the scm_stat_{add,del} helper can be invoked with no additional lock held. This clean-up the code a bit and will make the next patch easier. Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-28af_unix: Replace zero-length array with flexible-array memberGustavo A. R. Silva1-1/+1
The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-12unix: Show number of pending scm files of receive queue in fdinfoKirill Tkhai1-0/+5
Unix sockets like a block box. You never know what is stored there: there may be a file descriptor holding a mount or a block device, or there may be whole universes with namespaces, sockets with receive queues full of sockets etc. The patch adds a little debug and accounts number of files (not recursive), which is in receive queue of a unix socket. Sometimes this is useful to determine, that socket should be investigated or which task should be killed to put reference counter on a resourse. v2: Pass correct argument to lockdep Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-02-28net: split out functions related to registering inflight socket filesJens Axboe1-0/+1
We need this functionality for the io_uring file registration, but we cannot rely on it since CONFIG_UNIX can be modular. Move the helpers to a separate file, that's always builtin to the kernel if CONFIG_UNIX is m/y. No functional changes in this patch, just moving code around. Reviewed-by: Hannes Reinecke <hare@suse.com> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-10-31net: drop a space before tabsBo YU1-1/+1
Fix a warning from checkpatch.pl:'please no space before tabs' in include/net/af_unix.h Signed-off-by: Bo YU <tsu.yubo@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-31net: add an identifier name for 'struct sock *'Bo YU1-1/+1
Fix a warning from checkpatch: function definition argument 'struct sock *' should also have an identifier name in include/net/af_unix.h. Signed-off-by: Bo YU <tsu.yubo@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-22af_unix.h: trivial whitespace cleanupVito Caputo1-2/+2
Replace spurious spaces with a tab and remove superfluous tab from unix_sock struct. Signed-off-by: Vito Caputo <vcaputo@pengaru.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman1-0/+1
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-21Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-1/+1
2017-07-19Merge tag 'gcc-plugins-v4.13-rc2' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull structure randomization updates from Kees Cook: "Now that IPC and other changes have landed, enable manual markings for randstruct plugin, including the task_struct. This is the rest of what was staged in -next for the gcc-plugins, and comes in three patches, largest first: - mark "easy" structs with __randomize_layout - mark task_struct with an optional anonymous struct to isolate the __randomize_layout section - mark structs to opt _out_ of automated marking (which will come later) And, FWIW, this continues to pass allmodconfig (normal and patched to enable gcc-plugins) builds of x86_64, i386, arm64, arm, powerpc, and s390 for me" * tag 'gcc-plugins-v4.13-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: randstruct: opt-out externally exposed function pointer structs task_struct: Allow randomized layout randstruct: Mark various structs for randomization
2017-07-17net/unix: drop obsolete fd-recursion limitsDavid Herrmann1-1/+0
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 Torvalds1-1/+2
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, Elena1-1/+2
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>
2017-06-30randstruct: Mark various structs for randomizationKees Cook1-1/+1
This marks many critical kernel structures for randomization. These are structures that have been targeted in the past in security exploits, or contain functions pointers, pointers to function pointer tables, lists, workqueues, ref-counters, credentials, permissions, or are otherwise sensitive. This initial list was extracted from Brad Spengler/PaX Team's code in the last public patch of grsecurity/PaX based on my understanding of the code. Changes or omissions from the original code are mine and don't reflect the original grsecurity/PaX code. Left out of this list is task_struct, which requires special handling and will be covered in a subsequent patch. Signed-off-by: Kees Cook <keescook@chromium.org>
2017-06-20sched/wait: Rename wait_queue_t => wait_queue_entry_tIngo Molnar1-1/+1
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>
2016-09-04af_unix: split 'u->readlock' into two: 'iolock' and 'bindlock'Linus Torvalds1-1/+1
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>
2016-02-08unix: correctly track in-flight fds in sending process user_structHannes Frederic Sowa1-2/+2
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>
2015-11-23unix: avoid use-after-free in ep_remove_wait_queueRainer Weikusat1-0/+1
Rainer Weikusat <rweikusat@mobileactivedefense.com> writes: An AF_UNIX datagram socket being the client in an n:1 association with some server socket is only allowed to send messages to the server if the receive queue of this socket contains at most sk_max_ack_backlog datagrams. This implies that prospective writers might be forced to go to sleep despite none of the message presently enqueued on the server receive queue were sent by them. In order to ensure that these will be woken up once space becomes again available, the present unix_dgram_poll routine does a second sock_poll_wait call with the peer_wait wait queue of the server socket as queue argument (unix_dgram_recvmsg does a wake up on this queue after a datagram was received). This is inherently problematic because the server socket is only guaranteed to remain alive for as long as the client still holds a reference to it. In case the connection is dissolved via connect or by the dead peer detection logic in unix_dgram_sendmsg, the server socket may be freed despite "the polling mechanism" (in particular, epoll) still has a pointer to the corresponding peer_wait queue. There's no way to forcibly deregister a wait queue with epoll. Based on an idea by Jason Baron, the patch below changes the code such that a wait_queue_t belonging to the client socket is enqueued on the peer_wait queue of the server whenever the peer receive queue full condition is detected by either a sendmsg or a poll. A wake up on the peer queue is then relayed to the ordinary wait queue of the client socket via wake function. The connection to the peer wait queue is again dissolved if either a wake up is about to be relayed or the client socket reconnects or a dead peer is detected or the client socket is itself closed. This enables removing the second sock_poll_wait from unix_dgram_poll, thus avoiding the use-after-free, while still ensuring that no blocked writer sleeps forever. Signed-off-by: Rainer Weikusat <rweikusat@mobileactivedefense.com> Fixes: ec0d215f9420 ("af_unix: fix 'poll for write'/connected DGRAM sockets") Reviewed-by: Jason Baron <jbaron@akamai.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-08af_unix: constify the sock parameter in unix_sk()Paul Moore1-1/+1
Make unix_sk() just like inet[6]_sk() by constify'ing the sock parameter. Signed-off-by: Paul Moore <pmoore@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-29af_unix: Convert the unix_sk macro to an inline function for type safetyAaron Conole1-1/+5
As suggested by Eric Dumazet this change replaces the #define with a static inline function to enjoy complaints by the compiler when misusing the API. Signed-off-by: Aaron Conole <aconole@bytheb.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-06-10net/unix: support SCM_SECURITY for stream socketsStephen Smalley1-1/+0
SCM_SECURITY was originally only implemented for datagram sockets, not for stream sockets. However, SCM_CREDENTIALS is supported on Unix stream sockets. For consistency, implement Unix stream support for SCM_SECURITY as well. Also clean up the existing code and get rid of the superfluous UNIXSID macro. Motivated by https://bugzilla.redhat.com/show_bug.cgi?id=1224211, where systemd was using SCM_CREDENTIALS and assumed wrongly that SCM_SECURITY was also supported on Unix stream sockets. Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov> Acked-by: Paul Moore <paul@paul-moore.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-08-10af_unix: improve STREAM behavior with fragmented memoryEric Dumazet1-0/+1
unix_stream_sendmsg() currently uses order-2 allocations, and we had numerous reports this can fail. The __GFP_REPEAT flag present in sock_alloc_send_pskb() is not helping. This patch extends the work done in commit eb6a24816b247c ("af_unix: reduce high order page allocations) for datagram sockets. This opens the possibility of zero copy IO (splice() and friends) The trick is to not use skb_pull() anymore in recvmsg() path, and instead add a @consumed field in UNIXCB() to track amount of already read payload in the skb. There is a performance regression for large sends because of extra page allocations that will be addressed in a follow-up patch, allowing sock_alloc_send_pskb() to attempt high order page allocations. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-07-31af_unix.h: Remove extern from function prototypesJoe Perches1-8/+8
There are a mix of function prototypes with and without extern in the kernel sources. Standardize on not using extern for function prototypes. Function prototypes don't need to be written with extern. extern is assumed by the compiler. Its use is as unnecessary as using auto to declare automatic/local variables in a block. Reflow modified prototypes to 80 columns. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-05-01af_unix: fix a fatal race with bit fieldsEric Dumazet1-2/+3
Using bit fields is dangerous on ppc64/sparc64, as the compiler [1] uses 64bit instructions to manipulate them. If the 64bit word includes any atomic_t or spinlock_t, we can lose critical concurrent changes. This is happening in af_unix, where unix_sk(sk)->gc_candidate/ gc_maybe_cycle/lock share the same 64bit word. This leads to fatal deadlock, as one/several cpus spin forever on a spinlock that will never be available again. A safer way would be to use a long to store flags. This way we are sure compiler/arch wont do bad things. As we own unix_gc_lock spinlock when clearing or setting bits, we can use the non atomic __set_bit()/__clear_bit(). recursion_level can share the same 64bit location with the spinlock, as it is set only with this spinlock held. [1] bug fixed in gcc-4.8.0 : http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52080 Reported-by: Ambrose Feinstein <ambrose@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-04-07scm: Stop passing struct credEric W. Biederman1-1/+2
Now that uids and gids are completely encapsulated in kuid_t and kgid_t we no longer need to pass struct cred which allowed us to test both the uid and the user namespace for equality. Passing struct cred potentially allows us to pass the entire group list as BSD does but I don't believe the cost of cache line misses justifies retaining code for a future potential application. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-10-21unix: Remove unused field from unix_sockPavel Emelyanov1-1/+0
The struct sock *other one seem to be unused. Grep and make do not object. Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-08af_unix: speedup /proc/net/unixEric Dumazet1-1/+2
/proc/net/unix has quadratic behavior, and can hold unix_table_lock for a while if high number of unix sockets are alive. (90 ms for 200k sockets...) We already have a hash table, so its quite easy to use it. Problem is unbound sockets are still hashed in a single hash slot (unix_socket_table[UNIX_HASH_TABLE]) This patch also spreads unbound sockets to 256 hash slots, to speedup both /proc/net/unix and unix_diag. Time to read /proc/net/unix with 200k unix sockets : (time dd if=/proc/net/unix of=/dev/null bs=4k) before : 520 secs after : 2 secs Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-15net: cleanup unsigned to unsigned intEric Dumazet1-1/+1
Use of "unsigned int" is preferred to bare "unsigned" in net tree. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-03-20switch unix_sock to struct pathAl Viro1-2/+1
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-12-30af_unix: Move CINQ/COUTQ code to helpersPavel Emelyanov1-0/+3
Currently tcp diag reports rqlen and wqlen values similar to how the CINQ/COUTQ iotcls do. To make unix diag report these values in the same way move the respective code into helpers. Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-16af_unix: Export stuff required for diag modulePavel Emelyanov1-0/+3
Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-24net: Remove __KERNEL__ cpp checks from include/netDavid S. Miller1-2/+0
These header files are never installed to user consumption, so any __KERNEL__ cpp checks are superfluous. Projects should also not copy these files into their userland utility sources and try to use them there. If they insist on doing so, the onus is on them to sanitize the headers as needed. Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-29af_unix: limit recursion levelEric Dumazet1-0/+2
Its easy to eat all kernel memory and trigger NMI watchdog, using an exploit program that queues unix sockets on top of others. lkml ref : http://lkml.org/lkml/2010/11/25/8 This mechanism is used in applications, one choice we have is to have a recursion limit. Other limits might be needed as well (if we queue other types of files), since the passfd mechanism is currently limited by socket receive queue sizes only. Add a recursion_level to unix socket, allowing up to 4 levels. Each time we send an unix socket through sendfd mechanism, we copy its recursion level (plus one) to receiver. This recursion level is cleared when socket receive queue is emptied. Reported-by: Марк Коренберг <socketpair@gmail.com> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-06-16af_unix: Allow credentials to work across user and pid namespaces.Eric W. Biederman1-2/+2
In unix_skb_parms store pointers to struct pid and struct cred instead of raw uid, gid, and pid values, then translate the credentials on reception into values that are meaningful in the receiving processes namespaces. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Acked-by: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-05-01net: sock_def_readable() and friends RCU conversionEric Dumazet1-9/+11
sk_callback_lock rwlock actually protects sk->sk_sleep pointer, so we need two atomic operations (and associated dirtying) per incoming packet. RCU conversion is pretty much needed : 1) Add a new structure, called "struct socket_wq" to hold all fields that will need rcu_read_lock() protection (currently: a wait_queue_head_t and a struct fasync_struct pointer). [Future patch will add a list anchor for wakeup coalescing] 2) Attach one of such structure to each "struct socket" created in sock_alloc_inode(). 3) Respect RCU grace period when freeing a "struct socket_wq" 4) Change sk_sleep pointer in "struct sock" by sk_wq, pointer to "struct socket_wq" 5) Change sk_sleep() function to use new sk->sk_wq instead of sk->sk_sleep 6) Change sk_has_sleeper() to wq_has_sleeper() that must be used inside a rcu_read_lock() section. 7) Change all sk_has_sleeper() callers to : - Use rcu_read_lock() instead of read_lock(&sk->sk_callback_lock) - Use wq_has_sleeper() to eventually wakeup tasks. - Use rcu_read_unlock() instead of read_unlock(&sk->sk_callback_lock) 8) sock_wake_async() is modified to use rcu protection as well. 9) Exceptions : macvtap, drivers/net/tun.c, af_unix use integrated "struct socket_wq" instead of dynamically allocated ones. They dont need rcu freeing. Some cleanups or followups are probably needed, (possible sk_callback_lock conversion to a spinlock for example...). Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-26net: Fix soft lockups/OOM issues w/ unix garbage collectordann frazier1-0/+1
This is an implementation of David Miller's suggested fix in: https://bugzilla.redhat.com/show_bug.cgi?id=470201 It has been updated to use wait_event() instead of wait_event_interruptible(). Paraphrasing the description from the above report, it makes sendmsg() block while UNIX garbage collection is in progress. This avoids a situation where child processes continue to queue new FDs over a AF_UNIX socket to a parent which is in the exit path and running garbage collection on these FDs. This contention can result in soft lockups and oom-killing of unrelated processes. Signed-off-by: dann frazier <dannf@hp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-09net: unix: fix inflight counting bug in garbage collectorMiklos Szeredi1-0/+1
Previously I assumed that the receive queues of candidates don't change during the GC. This is only half true, nothing can be received from the queues (see comment in unix_gc()), but buffers could be added through the other half of the socket pair, which may still have file descriptors referring to it. This can result in inc_inflight_move_tail() erronously increasing the "inflight" counter for a unix socket for which dec_inflight() wasn't previously called. This in turn can trigger the "BUG_ON(total_refs < inflight_refs)" in a later garbage collection run. Fix this by only manipulating the "inflight" counter for sockets which are candidates themselves. Duplicating the file references in unix_attach_fds() is also needed to prevent a socket becoming a candidate for GC while the skb that contains it is not yet queued. Reported-by: Andrea Bittau <a.bittau@cs.ucl.ac.uk> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> CC: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-26[PATCH] f_count may wrap aroundAl Viro1-1/+1
make it atomic_long_t; while we are at it, get rid of useless checks in affs, hfs and hpfs - ->open() always has it equal to 1, ->release() - to 0. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-01-28[AF_UNIX]: Remove unused declaration of sysctl_unix_max_dgram_qlen.Denis V. Lunev1-1/+0
Signed-off-by: Denis V. Lunev <den@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[UNIX]: Extend unix_sysctl_(un)register prototypesPavel Emelyanov1-4/+4
Add the struct net * argument to both of them to use in the future. Also make the register one return an error code. It is useless right now, but will make the future patches much simpler. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Acked-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-11-10[AF_UNIX]: Make unix_tot_inflight counter non-atomicPavel Emelyanov1-1/+1
This counter is _always_ modified under the unix_gc_lock spinlock, so its atomicity can be provided w/o additional efforts. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-07-31[AF_UNIX]: Make code static.Adrian Bunk1-29/+0
The following code can now become static: - struct unix_socket_table - unix_table_lock Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-07-11[AF_UNIX]: Rewrite garbage collector, fixes race.Miklos Szeredi1-1/+2
Throw out the old mark & sweep garbage collector and put in a refcounting cycle detecting one. The old one had a race with recvmsg, that resulted in false positives and hence data loss. The old algorithm operated on all unix sockets in the system, so any additional locking would have meant performance problems for all users of these. The new algorithm instead only operates on "in flight" sockets, which are very rare, and the additional locking for these doesn't negatively impact the vast majority of users. In fact it's probable, that there weren't *any* heavy senders of sockets over sockets, otherwise the above race would have been discovered long ago. The patch works OK with the app that exposed the race with the old code. The garbage collection has also been verified to work in a few simple cases. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-06-03[AF_UNIX]: Make socket locking much less confusing.David S. Miller1-5/+3
The unix_state_*() locking macros imply that there is some rwlock kind of thing going on, but the implementation is actually a spinlock which makes the code more confusing than it needs to be. So use plain unix_state_lock and unix_state_unlock. Signed-off-by: David S. Miller <davem@davemloft.net>
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