linux/net/core/stream.c

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License cleanup: add SPDX GPL-2.0 license identifier to files with no license 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>
2017-11-01 22:07:57 +08:00
// SPDX-License-Identifier: GPL-2.0
/*
* SUCS NET3:
*
* Generic stream handling routines. These are generic for most
* protocols. Even IP. Tonight 8-).
* This is used because TCP, LLC (others too) layer all have mostly
* identical sendmsg() and recvmsg() code.
* So we (will) share it here.
*
* Authors: Arnaldo Carvalho de Melo <acme@conectiva.com.br>
* (from old tcp.c code)
* Alan Cox <alan@lxorguk.ukuu.org.uk> (Borrowed comments 8-))
*/
#include <linux/module.h>
#include <linux/sched/signal.h>
#include <linux/net.h>
#include <linux/signal.h>
#include <linux/tcp.h>
#include <linux/wait.h>
#include <net/sock.h>
/**
* sk_stream_write_space - stream socket write_space callback.
[PATCH] DocBook: changes and extensions to the kernel documentation I have recompiled Linux kernel 2.6.11.5 documentation for me and our university students again. The documentation could be extended for more sources which are equipped by structured comments for recent 2.6 kernels. I have tried to proceed with that task. I have done that more times from 2.6.0 time and it gets boring to do same changes again and again. Linux kernel compiles after changes for i386 and ARM targets. I have added references to some more files into kernel-api book, I have added some section names as well. So please, check that changes do not break something and that categories are not too much skewed. I have changed kernel-doc to accept "fastcall" and "asmlinkage" words reserved by kernel convention. Most of the other changes are modifications in the comments to make kernel-doc happy, accept some parameters description and do not bail out on errors. Changed <pid> to @pid in the description, moved some #ifdef before comments to correct function to comments bindings, etc. You can see result of the modified documentation build at http://cmp.felk.cvut.cz/~pisa/linux/lkdb-2.6.11.tar.gz Some more sources are ready to be included into kernel-doc generated documentation. Sources has been added into kernel-api for now. Some more section names added and probably some more chaos introduced as result of quick cleanup work. Signed-off-by: Pavel Pisa <pisa@cmp.felk.cvut.cz> Signed-off-by: Martin Waitz <tali@admingilde.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-01 23:59:25 +08:00
* @sk: socket
*
* FIXME: write proper description
*/
void sk_stream_write_space(struct sock *sk)
{
struct socket *sock = sk->sk_socket;
net: sock_def_readable() and friends RCU conversion 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>
2010-04-29 19:01:49 +08:00
struct socket_wq *wq;
tcp: reduce POLLOUT events caused by TCP_NOTSENT_LOWAT TCP_NOTSENT_LOWAT socket option or sysctl was added in linux-3.12 as a step to enable bigger tcp sndbuf limits. It works reasonably well, but the following happens : Once the limit is reached, TCP stack generates an [E]POLLOUT event for every incoming ACK packet. This causes a high number of context switches. This patch implements the strategy David Miller added in sock_def_write_space() : - If TCP socket has a notsent_lowat constraint of X bytes, allow sendmsg() to fill up to X bytes, but send [E]POLLOUT only if number of notsent bytes is below X/2 This considerably reduces TCP_NOTSENT_LOWAT overhead, while allowing to keep the pipe full. Tested: 100 ms RTT netem testbed between A and B, 100 concurrent TCP_STREAM A:/# cat /proc/sys/net/ipv4/tcp_wmem 4096 262144 64000000 A:/# super_netperf 100 -H B -l 1000 -- -K bbr & A:/# grep TCP /proc/net/sockstat TCP: inuse 203 orphan 0 tw 19 alloc 414 mem 1364904 # This is about 54 MB of memory per flow :/ A:/# vmstat 5 5 procs -----------memory---------- ---swap-- -----io---- -system-- ------cpu----- r b swpd free buff cache si so bi bo in cs us sy id wa st 0 0 0 256220672 13532 694976 0 0 10 0 28 14 0 1 99 0 0 2 0 0 256320016 13532 698480 0 0 512 0 715901 5927 0 10 90 0 0 0 0 0 256197232 13532 700992 0 0 735 13 771161 5849 0 11 89 0 0 1 0 0 256233824 13532 703320 0 0 512 23 719650 6635 0 11 89 0 0 2 0 0 256226880 13532 705780 0 0 642 4 775650 6009 0 12 88 0 0 A:/# echo 2097152 >/proc/sys/net/ipv4/tcp_notsent_lowat A:/# grep TCP /proc/net/sockstat TCP: inuse 203 orphan 0 tw 19 alloc 414 mem 86411 # 3.5 MB per flow A:/# vmstat 5 5 # check that context switches have not inflated too much. procs -----------memory---------- ---swap-- -----io---- -system-- ------cpu----- r b swpd free buff cache si so bi bo in cs us sy id wa st 2 0 0 260386512 13592 662148 0 0 10 0 17 14 0 1 99 0 0 0 0 0 260519680 13592 604184 0 0 512 13 726843 12424 0 10 90 0 0 1 1 0 260435424 13592 598360 0 0 512 25 764645 12925 0 10 90 0 0 1 0 0 260855392 13592 578380 0 0 512 7 722943 13624 0 11 88 0 0 1 0 0 260445008 13592 601176 0 0 614 34 772288 14317 0 10 90 0 0 Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-04 23:58:17 +08:00
if (__sk_stream_is_writeable(sk, 1) && sock) {
clear_bit(SOCK_NOSPACE, &sock->flags);
net: sock_def_readable() and friends RCU conversion 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>
2010-04-29 19:01:49 +08:00
rcu_read_lock();
wq = rcu_dereference(sk->sk_wq);
if (skwq_has_sleeper(wq))
wake_up_interruptible_poll(&wq->wait, EPOLLOUT |
EPOLLWRNORM | EPOLLWRBAND);
net: sock_def_readable() and friends RCU conversion 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>
2010-04-29 19:01:49 +08:00
if (wq && wq->fasync_list && !(sk->sk_shutdown & SEND_SHUTDOWN))
sock_wake_async(wq, SOCK_WAKE_SPACE, POLL_OUT);
net: sock_def_readable() and friends RCU conversion 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>
2010-04-29 19:01:49 +08:00
rcu_read_unlock();
}
}
/**
* sk_stream_wait_connect - Wait for a socket to get into the connected state
[PATCH] DocBook: changes and extensions to the kernel documentation I have recompiled Linux kernel 2.6.11.5 documentation for me and our university students again. The documentation could be extended for more sources which are equipped by structured comments for recent 2.6 kernels. I have tried to proceed with that task. I have done that more times from 2.6.0 time and it gets boring to do same changes again and again. Linux kernel compiles after changes for i386 and ARM targets. I have added references to some more files into kernel-api book, I have added some section names as well. So please, check that changes do not break something and that categories are not too much skewed. I have changed kernel-doc to accept "fastcall" and "asmlinkage" words reserved by kernel convention. Most of the other changes are modifications in the comments to make kernel-doc happy, accept some parameters description and do not bail out on errors. Changed <pid> to @pid in the description, moved some #ifdef before comments to correct function to comments bindings, etc. You can see result of the modified documentation build at http://cmp.felk.cvut.cz/~pisa/linux/lkdb-2.6.11.tar.gz Some more sources are ready to be included into kernel-doc generated documentation. Sources has been added into kernel-api for now. Some more section names added and probably some more chaos introduced as result of quick cleanup work. Signed-off-by: Pavel Pisa <pisa@cmp.felk.cvut.cz> Signed-off-by: Martin Waitz <tali@admingilde.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-01 23:59:25 +08:00
* @sk: sock to wait on
* @timeo_p: for how long to wait
*
* Must be called with the socket locked.
*/
int sk_stream_wait_connect(struct sock *sk, long *timeo_p)
{
DEFINE_WAIT_FUNC(wait, woken_wake_function);
struct task_struct *tsk = current;
int done;
do {
int err = sock_error(sk);
if (err)
return err;
if ((1 << sk->sk_state) & ~(TCPF_SYN_SENT | TCPF_SYN_RECV))
return -EPIPE;
if (!*timeo_p)
return -EAGAIN;
if (signal_pending(tsk))
return sock_intr_errno(*timeo_p);
add_wait_queue(sk_sleep(sk), &wait);
sk->sk_write_pending++;
done = sk_wait_event(sk, timeo_p,
net: deal with most data-races in sk_wait_event() __condition is evaluated twice in sk_wait_event() macro. First invocation is lockless, and reads can race with writes, as spotted by syzbot. BUG: KCSAN: data-race in sk_stream_wait_connect / tcp_disconnect write to 0xffff88812d83d6a0 of 4 bytes by task 9065 on cpu 1: tcp_disconnect+0x2cd/0xdb0 inet_shutdown+0x19e/0x1f0 net/ipv4/af_inet.c:911 __sys_shutdown_sock net/socket.c:2343 [inline] __sys_shutdown net/socket.c:2355 [inline] __do_sys_shutdown net/socket.c:2363 [inline] __se_sys_shutdown+0xf8/0x140 net/socket.c:2361 __x64_sys_shutdown+0x31/0x40 net/socket.c:2361 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd read to 0xffff88812d83d6a0 of 4 bytes by task 9040 on cpu 0: sk_stream_wait_connect+0x1de/0x3a0 net/core/stream.c:75 tcp_sendmsg_locked+0x2e4/0x2120 net/ipv4/tcp.c:1266 tcp_sendmsg+0x30/0x50 net/ipv4/tcp.c:1484 inet6_sendmsg+0x63/0x80 net/ipv6/af_inet6.c:651 sock_sendmsg_nosec net/socket.c:724 [inline] sock_sendmsg net/socket.c:747 [inline] __sys_sendto+0x246/0x300 net/socket.c:2142 __do_sys_sendto net/socket.c:2154 [inline] __se_sys_sendto net/socket.c:2150 [inline] __x64_sys_sendto+0x78/0x90 net/socket.c:2150 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd value changed: 0x00000000 -> 0x00000068 Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-05-10 02:29:48 +08:00
!READ_ONCE(sk->sk_err) &&
!((1 << READ_ONCE(sk->sk_state)) &
~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)), &wait);
remove_wait_queue(sk_sleep(sk), &wait);
sk->sk_write_pending--;
} while (!done);
net: Return error from sk_stream_wait_connect() if sk_wait_event() fails The following NULL pointer dereference issue occurred: BUG: kernel NULL pointer dereference, address: 0000000000000000 <...> RIP: 0010:ccid_hc_tx_send_packet net/dccp/ccid.h:166 [inline] RIP: 0010:dccp_write_xmit+0x49/0x140 net/dccp/output.c:356 <...> Call Trace: <TASK> dccp_sendmsg+0x642/0x7e0 net/dccp/proto.c:801 inet_sendmsg+0x63/0x90 net/ipv4/af_inet.c:846 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x83/0xe0 net/socket.c:745 ____sys_sendmsg+0x443/0x510 net/socket.c:2558 ___sys_sendmsg+0xe5/0x150 net/socket.c:2612 __sys_sendmsg+0xa6/0x120 net/socket.c:2641 __do_sys_sendmsg net/socket.c:2650 [inline] __se_sys_sendmsg net/socket.c:2648 [inline] __x64_sys_sendmsg+0x45/0x50 net/socket.c:2648 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x43/0x110 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x63/0x6b sk_wait_event() returns an error (-EPIPE) if disconnect() is called on the socket waiting for the event. However, sk_stream_wait_connect() returns success, i.e. zero, even if sk_wait_event() returns -EPIPE, so a function that waits for a connection with sk_stream_wait_connect() may misbehave. In the case of the above DCCP issue, dccp_sendmsg() is waiting for the connection. If disconnect() is called in concurrently, the above issue occurs. This patch fixes the issue by returning error from sk_stream_wait_connect() if sk_wait_event() fails. Fixes: 419ce133ab92 ("tcp: allow again tcp_disconnect() when threads are waiting") Signed-off-by: Shigeru Yoshida <syoshida@redhat.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reported-by: syzbot+c71bc336c5061153b502@syzkaller.appspotmail.com Reviewed-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Reported-by: syzkaller <syzkaller@googlegroups.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-12-14 13:09:22 +08:00
return done < 0 ? done : 0;
}
EXPORT_SYMBOL(sk_stream_wait_connect);
/**
* sk_stream_closing - Return 1 if we still have things to send in our buffers.
[PATCH] DocBook: changes and extensions to the kernel documentation I have recompiled Linux kernel 2.6.11.5 documentation for me and our university students again. The documentation could be extended for more sources which are equipped by structured comments for recent 2.6 kernels. I have tried to proceed with that task. I have done that more times from 2.6.0 time and it gets boring to do same changes again and again. Linux kernel compiles after changes for i386 and ARM targets. I have added references to some more files into kernel-api book, I have added some section names as well. So please, check that changes do not break something and that categories are not too much skewed. I have changed kernel-doc to accept "fastcall" and "asmlinkage" words reserved by kernel convention. Most of the other changes are modifications in the comments to make kernel-doc happy, accept some parameters description and do not bail out on errors. Changed <pid> to @pid in the description, moved some #ifdef before comments to correct function to comments bindings, etc. You can see result of the modified documentation build at http://cmp.felk.cvut.cz/~pisa/linux/lkdb-2.6.11.tar.gz Some more sources are ready to be included into kernel-doc generated documentation. Sources has been added into kernel-api for now. Some more section names added and probably some more chaos introduced as result of quick cleanup work. Signed-off-by: Pavel Pisa <pisa@cmp.felk.cvut.cz> Signed-off-by: Martin Waitz <tali@admingilde.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-01 23:59:25 +08:00
* @sk: socket to verify
*/
net: deal with most data-races in sk_wait_event() __condition is evaluated twice in sk_wait_event() macro. First invocation is lockless, and reads can race with writes, as spotted by syzbot. BUG: KCSAN: data-race in sk_stream_wait_connect / tcp_disconnect write to 0xffff88812d83d6a0 of 4 bytes by task 9065 on cpu 1: tcp_disconnect+0x2cd/0xdb0 inet_shutdown+0x19e/0x1f0 net/ipv4/af_inet.c:911 __sys_shutdown_sock net/socket.c:2343 [inline] __sys_shutdown net/socket.c:2355 [inline] __do_sys_shutdown net/socket.c:2363 [inline] __se_sys_shutdown+0xf8/0x140 net/socket.c:2361 __x64_sys_shutdown+0x31/0x40 net/socket.c:2361 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd read to 0xffff88812d83d6a0 of 4 bytes by task 9040 on cpu 0: sk_stream_wait_connect+0x1de/0x3a0 net/core/stream.c:75 tcp_sendmsg_locked+0x2e4/0x2120 net/ipv4/tcp.c:1266 tcp_sendmsg+0x30/0x50 net/ipv4/tcp.c:1484 inet6_sendmsg+0x63/0x80 net/ipv6/af_inet6.c:651 sock_sendmsg_nosec net/socket.c:724 [inline] sock_sendmsg net/socket.c:747 [inline] __sys_sendto+0x246/0x300 net/socket.c:2142 __do_sys_sendto net/socket.c:2154 [inline] __se_sys_sendto net/socket.c:2150 [inline] __x64_sys_sendto+0x78/0x90 net/socket.c:2150 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd value changed: 0x00000000 -> 0x00000068 Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-05-10 02:29:48 +08:00
static int sk_stream_closing(const struct sock *sk)
{
net: deal with most data-races in sk_wait_event() __condition is evaluated twice in sk_wait_event() macro. First invocation is lockless, and reads can race with writes, as spotted by syzbot. BUG: KCSAN: data-race in sk_stream_wait_connect / tcp_disconnect write to 0xffff88812d83d6a0 of 4 bytes by task 9065 on cpu 1: tcp_disconnect+0x2cd/0xdb0 inet_shutdown+0x19e/0x1f0 net/ipv4/af_inet.c:911 __sys_shutdown_sock net/socket.c:2343 [inline] __sys_shutdown net/socket.c:2355 [inline] __do_sys_shutdown net/socket.c:2363 [inline] __se_sys_shutdown+0xf8/0x140 net/socket.c:2361 __x64_sys_shutdown+0x31/0x40 net/socket.c:2361 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd read to 0xffff88812d83d6a0 of 4 bytes by task 9040 on cpu 0: sk_stream_wait_connect+0x1de/0x3a0 net/core/stream.c:75 tcp_sendmsg_locked+0x2e4/0x2120 net/ipv4/tcp.c:1266 tcp_sendmsg+0x30/0x50 net/ipv4/tcp.c:1484 inet6_sendmsg+0x63/0x80 net/ipv6/af_inet6.c:651 sock_sendmsg_nosec net/socket.c:724 [inline] sock_sendmsg net/socket.c:747 [inline] __sys_sendto+0x246/0x300 net/socket.c:2142 __do_sys_sendto net/socket.c:2154 [inline] __se_sys_sendto net/socket.c:2150 [inline] __x64_sys_sendto+0x78/0x90 net/socket.c:2150 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd value changed: 0x00000000 -> 0x00000068 Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-05-10 02:29:48 +08:00
return (1 << READ_ONCE(sk->sk_state)) &
(TCPF_FIN_WAIT1 | TCPF_CLOSING | TCPF_LAST_ACK);
}
void sk_stream_wait_close(struct sock *sk, long timeout)
{
if (timeout) {
DEFINE_WAIT_FUNC(wait, woken_wake_function);
add_wait_queue(sk_sleep(sk), &wait);
do {
if (sk_wait_event(sk, &timeout, !sk_stream_closing(sk), &wait))
break;
} while (!signal_pending(current) && timeout);
remove_wait_queue(sk_sleep(sk), &wait);
}
}
EXPORT_SYMBOL(sk_stream_wait_close);
/**
* sk_stream_wait_memory - Wait for more memory for a socket
[PATCH] DocBook: changes and extensions to the kernel documentation I have recompiled Linux kernel 2.6.11.5 documentation for me and our university students again. The documentation could be extended for more sources which are equipped by structured comments for recent 2.6 kernels. I have tried to proceed with that task. I have done that more times from 2.6.0 time and it gets boring to do same changes again and again. Linux kernel compiles after changes for i386 and ARM targets. I have added references to some more files into kernel-api book, I have added some section names as well. So please, check that changes do not break something and that categories are not too much skewed. I have changed kernel-doc to accept "fastcall" and "asmlinkage" words reserved by kernel convention. Most of the other changes are modifications in the comments to make kernel-doc happy, accept some parameters description and do not bail out on errors. Changed <pid> to @pid in the description, moved some #ifdef before comments to correct function to comments bindings, etc. You can see result of the modified documentation build at http://cmp.felk.cvut.cz/~pisa/linux/lkdb-2.6.11.tar.gz Some more sources are ready to be included into kernel-doc generated documentation. Sources has been added into kernel-api for now. Some more section names added and probably some more chaos introduced as result of quick cleanup work. Signed-off-by: Pavel Pisa <pisa@cmp.felk.cvut.cz> Signed-off-by: Martin Waitz <tali@admingilde.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-01 23:59:25 +08:00
* @sk: socket to wait for memory
* @timeo_p: for how long
*/
int sk_stream_wait_memory(struct sock *sk, long *timeo_p)
{
int ret, err = 0;
long vm_wait = 0;
long current_timeo = *timeo_p;
DEFINE_WAIT_FUNC(wait, woken_wake_function);
if (sk_stream_memory_free(sk))
current_timeo = vm_wait = get_random_u32_below(HZ / 5) + 2;
add_wait_queue(sk_sleep(sk), &wait);
while (1) {
sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
goto do_error;
if (!*timeo_p)
goto do_eagain;
if (signal_pending(current))
goto do_interrupted;
sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
if (sk_stream_memory_free(sk) && !vm_wait)
break;
set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
sk->sk_write_pending++;
ret = sk_wait_event(sk, &current_timeo, READ_ONCE(sk->sk_err) ||
(READ_ONCE(sk->sk_shutdown) & SEND_SHUTDOWN) ||
(sk_stream_memory_free(sk) && !vm_wait),
&wait);
sk->sk_write_pending--;
if (ret < 0)
goto do_error;
if (vm_wait) {
vm_wait -= current_timeo;
current_timeo = *timeo_p;
if (current_timeo != MAX_SCHEDULE_TIMEOUT &&
(current_timeo -= vm_wait) < 0)
current_timeo = 0;
vm_wait = 0;
}
*timeo_p = current_timeo;
}
out:
net: If sock is dead don't access sock's sk_wq in sk_stream_wait_memory Fixes the below NULL pointer dereference: [...] [ 14.471200] Call Trace: [ 14.471562] <TASK> [ 14.471882] lock_acquire+0x245/0x2e0 [ 14.472416] ? remove_wait_queue+0x12/0x50 [ 14.473014] ? _raw_spin_lock_irqsave+0x17/0x50 [ 14.473681] _raw_spin_lock_irqsave+0x3d/0x50 [ 14.474318] ? remove_wait_queue+0x12/0x50 [ 14.474907] remove_wait_queue+0x12/0x50 [ 14.475480] sk_stream_wait_memory+0x20d/0x340 [ 14.476127] ? do_wait_intr_irq+0x80/0x80 [ 14.476704] do_tcp_sendpages+0x287/0x600 [ 14.477283] tcp_bpf_push+0xab/0x260 [ 14.477817] tcp_bpf_sendmsg_redir+0x297/0x500 [ 14.478461] ? __local_bh_enable_ip+0x77/0xe0 [ 14.479096] tcp_bpf_send_verdict+0x105/0x470 [ 14.479729] tcp_bpf_sendmsg+0x318/0x4f0 [ 14.480311] sock_sendmsg+0x2d/0x40 [ 14.480822] ____sys_sendmsg+0x1b4/0x1c0 [ 14.481390] ? copy_msghdr_from_user+0x62/0x80 [ 14.482048] ___sys_sendmsg+0x78/0xb0 [ 14.482580] ? vmf_insert_pfn_prot+0x91/0x150 [ 14.483215] ? __do_fault+0x2a/0x1a0 [ 14.483738] ? do_fault+0x15e/0x5d0 [ 14.484246] ? __handle_mm_fault+0x56b/0x1040 [ 14.484874] ? lock_is_held_type+0xdf/0x130 [ 14.485474] ? find_held_lock+0x2d/0x90 [ 14.486046] ? __sys_sendmsg+0x41/0x70 [ 14.486587] __sys_sendmsg+0x41/0x70 [ 14.487105] ? intel_pmu_drain_pebs_core+0x350/0x350 [ 14.487822] do_syscall_64+0x34/0x80 [ 14.488345] entry_SYSCALL_64_after_hwframe+0x63/0xcd [...] The test scenario has the following flow: thread1 thread2 ----------- --------------- tcp_bpf_sendmsg tcp_bpf_send_verdict tcp_bpf_sendmsg_redir sock_close tcp_bpf_push_locked __sock_release tcp_bpf_push //inet_release do_tcp_sendpages sock->ops->release sk_stream_wait_memory // tcp_close sk_wait_event sk->sk_prot->close release_sock(__sk); *** lock_sock(sk); __tcp_close sock_orphan(sk) sk->sk_wq = NULL release_sock **** lock_sock(__sk); remove_wait_queue(sk_sleep(sk), &wait); sk_sleep(sk) //NULL pointer dereference &rcu_dereference_raw(sk->sk_wq)->wait While waiting for memory in thread1, the socket is released with its wait queue because thread2 has closed it. This caused by tcp_bpf_send_verdict didn't increase the f_count of psock->sk_redir->sk_socket->file in thread1. We should check if SOCK_DEAD flag is set on wakeup in sk_stream_wait_memory before accessing the wait queue. Suggested-by: Jakub Sitnicki <jakub@cloudflare.com> Signed-off-by: Liu Jian <liujian56@huawei.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: John Fastabend <john.fastabend@gmail.com> Cc: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/bpf/20220823133755.314697-2-liujian56@huawei.com
2022-08-23 21:37:54 +08:00
if (!sock_flag(sk, SOCK_DEAD))
remove_wait_queue(sk_sleep(sk), &wait);
return err;
do_error:
err = -EPIPE;
goto out;
do_eagain:
/* Make sure that whenever EAGAIN is returned, EPOLLOUT event can
* be generated later.
* When TCP receives ACK packets that make room, tcp_check_space()
* only calls tcp_new_space() if SOCK_NOSPACE is set.
*/
set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
err = -EAGAIN;
goto out;
do_interrupted:
err = sock_intr_errno(*timeo_p);
goto out;
}
EXPORT_SYMBOL(sk_stream_wait_memory);
int sk_stream_error(struct sock *sk, int flags, int err)
{
if (err == -EPIPE)
err = sock_error(sk) ? : -EPIPE;
if (err == -EPIPE && !(flags & MSG_NOSIGNAL))
send_sig(SIGPIPE, current, 0);
return err;
}
EXPORT_SYMBOL(sk_stream_error);
void sk_stream_kill_queues(struct sock *sk)
{
/* First the read buffer. */
__skb_queue_purge(&sk->sk_receive_queue);
/* Next, the error queue.
* We need to use queue lock, because other threads might
* add packets to the queue without socket lock being held.
*/
skb_queue_purge(&sk->sk_error_queue);
/* Next, the write queue. */
WARN_ON_ONCE(!skb_queue_empty(&sk->sk_write_queue));
/* Account for returned memory. */
sk_mem_reclaim_final(sk);
WARN_ON_ONCE(sk->sk_wmem_queued);
/* It is _impossible_ for the backlog to contain anything
* when we get here. All user references to this socket
* have gone away, only the net layer knows can touch it.
*/
}
EXPORT_SYMBOL(sk_stream_kill_queues);