- 22 8月, 2012 1 次提交
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由 Eric Dumazet 提交于
Pablo Neira Ayuso discovered that avahi and potentially NetworkManager accept spoofed Netlink messages because of a kernel bug. The kernel passes all-zero SCM_CREDENTIALS ancillary data to the receiver if the sender did not provide such data, instead of not including any such data at all or including the correct data from the peer (as it is the case with AF_UNIX). This bug was introduced in commit 16e57262 (af_unix: dont send SCM_CREDENTIALS by default) This patch forces passing credentials for netlink, as before the regression. Another fix would be to not add SCM_CREDENTIALS in netlink messages if not provided by the sender, but it might break some programs. With help from Florian Weimer & Petr Matousek This issue is designated as CVE-2012-3520 Signed-off-by: NEric Dumazet <edumazet@google.com> Cc: Petr Matousek <pmatouse@redhat.com> Cc: Florian Weimer <fweimer@redhat.com> Cc: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 30 7月, 2012 3 次提交
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由 Al Viro 提交于
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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由 Al Viro 提交于
One side effect - attempt to create a cross-device link on a read-only fs fails with EROFS instead of EXDEV now. Makes more sense, POSIX allows, etc. Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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由 Al Viro 提交于
releases what needs to be released after {kern,user}_path_create() Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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- 10 6月, 2012 1 次提交
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由 Eric Dumazet 提交于
As pointed out by Michael Tokarev , struct unix_iter_state is no longer needed. Suggested-by: NMichael Tokarev <mjt@tls.msk.ru> Signed-off-by: NEric Dumazet <edumazet@google.com> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 09 6月, 2012 1 次提交
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由 Eric Dumazet 提交于
/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: NEric Dumazet <edumazet@google.com> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 16 4月, 2012 1 次提交
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由 Eric Dumazet 提交于
Use of "unsigned int" is preferred to bare "unsigned" in net tree. Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 04 4月, 2012 1 次提交
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由 Eric Dumazet 提交于
unix_dgram_sendmsg() currently builds linear skbs, and this can stress page allocator with high order page allocations. When memory gets fragmented, this can eventually fail. We can try to use order-2 allocations for skb head (SKB_MAX_ALLOC) plus up to 16 page fragments to lower pressure on buddy allocator. This patch has no effect on messages of less than 16064 bytes. (on 64bit arches with PAGE_SIZE=4096) For bigger messages (from 16065 to 81600 bytes), this patch brings reliability at the expense of performance penalty because of extra pages allocations. netperf -t DG_STREAM -T 0,2 -- -m 16064 -s 200000 ->4086040 Messages / 10s netperf -t DG_STREAM -T 0,2 -- -m 16068 -s 200000 ->3901747 Messages / 10s Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 24 3月, 2012 1 次提交
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由 Hans Verkuil 提交于
In some cases the poll() implementation in a driver has to do different things depending on the events the caller wants to poll for. An example is when a driver needs to start a DMA engine if the caller polls for POLLIN, but doesn't want to do that if POLLIN is not requested but instead only POLLOUT or POLLPRI is requested. This is something that can happen in the video4linux subsystem among others. Unfortunately, the current epoll/poll/select implementation doesn't provide that information reliably. The poll_table_struct does have it: it has a key field with the event mask. But once a poll() call matches one or more bits of that mask any following poll() calls are passed a NULL poll_table pointer. Also, the eventpoll implementation always left the key field at ~0 instead of using the requested events mask. This was changed in eventpoll.c so the key field now contains the actual events that should be polled for as set by the caller. The solution to the NULL poll_table pointer is to set the qproc field to NULL in poll_table once poll() matches the events, not the poll_table pointer itself. That way drivers can obtain the mask through a new poll_requested_events inline. The poll_table_struct can still be NULL since some kernel code calls it internally (netfs_state_poll() in ./drivers/staging/pohmelfs/netfs.h). In that case poll_requested_events() returns ~0 (i.e. all events). Very rarely drivers might want to know whether poll_wait will actually wait. If another earlier file descriptor in the set already matched the events the caller wanted to wait for, then the kernel will return from the select() call without waiting. This might be useful information in order to avoid doing expensive work. A new helper function poll_does_not_wait() is added that drivers can use to detect this situation. This is now used in sock_poll_wait() in include/net/sock.h. This was the only place in the kernel that needed this information. Drivers should no longer access any of the poll_table internals, but use the poll_requested_events() and poll_does_not_wait() access functions instead. In order to enforce that the poll_table fields are now prepended with an underscore and a comment was added warning against using them directly. This required a change in unix_dgram_poll() in unix/af_unix.c which used the key field to get the requested events. It's been replaced by a call to poll_requested_events(). For qproc it was especially important to change its name since the behavior of that field changes with this patch since this function pointer can now be NULL when that wasn't possible in the past. Any driver accessing the qproc or key fields directly will now fail to compile. Some notes regarding the correctness of this patch: the driver's poll() function is called with a 'struct poll_table_struct *wait' argument. This pointer may or may not be NULL, drivers can never rely on it being one or the other as that depends on whether or not an earlier file descriptor in the select()'s fdset matched the requested events. There are only three things a driver can do with the wait argument: 1) obtain the key field: events = wait ? wait->key : ~0; This will still work although it should be replaced with the new poll_requested_events() function (which does exactly the same). This will now even work better, since wait is no longer set to NULL unnecessarily. 2) use the qproc callback. This could be deadly since qproc can now be NULL. Renaming qproc should prevent this from happening. There are no kernel drivers that actually access this callback directly, BTW. 3) test whether wait == NULL to determine whether poll would return without waiting. This is no longer sufficient as the correct test is now wait == NULL || wait->_qproc == NULL. However, the worst that can happen here is a slight performance hit in the case where wait != NULL and wait->_qproc == NULL. In that case the driver will assume that poll_wait() will actually add the fd to the set of waiting file descriptors. Of course, poll_wait() will not do that since it tests for wait->_qproc. This will not break anything, though. There is only one place in the whole kernel where this happens (sock_poll_wait() in include/net/sock.h) and that code will be replaced by a call to poll_does_not_wait() in the next patch. Note that even if wait->_qproc != NULL drivers cannot rely on poll_wait() actually waiting. The next file descriptor from the set might match the event mask and thus any possible waits will never happen. Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com> Reviewed-by: NJonathan Corbet <corbet@lwn.net> Reviewed-by: NAl Viro <viro@zeniv.linux.org.uk> Cc: Davide Libenzi <davidel@xmailserver.org> Signed-off-by: NHans de Goede <hdegoede@redhat.com> Cc: Mauro Carvalho Chehab <mchehab@infradead.org> Cc: David Miller <davem@davemloft.net> Cc: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 21 3月, 2012 2 次提交
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由 Al Viro 提交于
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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由 Al Viro 提交于
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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- 23 2月, 2012 1 次提交
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由 Eric Dumazet 提交于
Piergiorgio Beruto expressed the need to fetch size of first datagram in queue for AF_UNIX sockets and suggested a patch against SIOCINQ ioctl. I suggested instead to implement MSG_TRUNC support as a recv() input flag, as already done for RAW, UDP & NETLINK sockets. len = recv(fd, &byte, 1, MSG_PEEK | MSG_TRUNC); MSG_TRUNC asks recv() to return the real length of the packet, even when is was longer than the passed buffer. There is risk that a userland application used MSG_TRUNC by accident (since it had no effect on af_unix sockets) and this might break after this patch. Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com> Tested-by: NPiergiorgio Beruto <piergiorgio.beruto@gmail.com> CC: Michael Kerrisk <mtk.manpages@gmail.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 22 2月, 2012 2 次提交
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由 Pavel Emelyanov 提交于
The same here -- we can protect the sk_peek_off manipulations with the unix_sk->readlock mutex. The peeking of data from a stream socket is done in the datagram style, i.e. even if there's enough room for more data in the user buffer, only the head skb's data is copied in there. This feature is preserved when peeking data from a given offset -- the data is read till the nearest skb's boundary. Signed-off-by: NPavel Emelyanov <xemul@parallels.com> Acked-by: NEric Dumazet <eric.dumazet@gmail.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Pavel Emelyanov 提交于
The sk_peek_off manipulations are protected with the unix_sk->readlock mutex. This mutex is enough since all we need is to syncronize setting the offset vs reading the queue head. The latter is fully covered with the mentioned lock. The recently added __skb_recv_datagram's offset is used to pick the skb to read the data from. Signed-off-by: NPavel Emelyanov <xemul@parallels.com> Acked-by: NEric Dumazet <eric.dumazet@gmail.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 31 1月, 2012 1 次提交
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由 Eric Dumazet 提交于
Commit 0884d7aa (AF_UNIX: Fix poll blocking problem when reading from a stream socket) added a regression for epoll() in Edge Triggered mode (EPOLLET) Appropriate fix is to use skb_peek()/skb_unlink() instead of skb_dequeue(), and only call skb_unlink() when skb is fully consumed. This remove the need to requeue a partial skb into sk_receive_queue head and the extra sk->sk_data_ready() calls that added the regression. This is safe because once skb is given to sk_receive_queue, it is not modified by a writer, and readers are serialized by u->readlock mutex. This also reduce number of spinlock acquisition for small reads or MSG_PEEK users so should improve overall performance. Reported-by: NNick Mathewson <nickm@freehaven.net> Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com> Cc: Alexey Moiseytsev <himeraster@gmail.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 04 1月, 2012 1 次提交
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由 Al Viro 提交于
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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- 31 12月, 2011 1 次提交
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由 Pavel Emelyanov 提交于
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: NPavel Emelyanov <xemul@parallels.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 17 12月, 2011 1 次提交
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由 Pavel Emelyanov 提交于
Signed-off-by: NPavel Emelyanov <xemul@parallels.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 27 11月, 2011 1 次提交
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由 Alexey Moiseytsev 提交于
poll() call may be blocked by concurrent reading from the same stream socket. Signed-off-by: NAlexey Moiseytsev <himeraster@gmail.com> Acked-by: NEric Dumazet <eric.dumazet@gmail.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 29 9月, 2011 1 次提交
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由 Eric Dumazet 提交于
Since commit 7361c36c (af_unix: Allow credentials to work across user and pid namespaces) af_unix performance dropped a lot. This is because we now take a reference on pid and cred in each write(), and release them in read(), usually done from another process, eventually from another cpu. This triggers false sharing. # Events: 154K cycles # # Overhead Command Shared Object Symbol # ........ ....... .................. ......................... # 10.40% hackbench [kernel.kallsyms] [k] put_pid 8.60% hackbench [kernel.kallsyms] [k] unix_stream_recvmsg 7.87% hackbench [kernel.kallsyms] [k] unix_stream_sendmsg 6.11% hackbench [kernel.kallsyms] [k] do_raw_spin_lock 4.95% hackbench [kernel.kallsyms] [k] unix_scm_to_skb 4.87% hackbench [kernel.kallsyms] [k] pid_nr_ns 4.34% hackbench [kernel.kallsyms] [k] cred_to_ucred 2.39% hackbench [kernel.kallsyms] [k] unix_destruct_scm 2.24% hackbench [kernel.kallsyms] [k] sub_preempt_count 1.75% hackbench [kernel.kallsyms] [k] fget_light 1.51% hackbench [kernel.kallsyms] [k] __mutex_lock_interruptible_slowpath 1.42% hackbench [kernel.kallsyms] [k] sock_alloc_send_pskb This patch includes SCM_CREDENTIALS information in a af_unix message/skb only if requested by the sender, [man 7 unix for details how to include ancillary data using sendmsg() system call] Note: This might break buggy applications that expected SCM_CREDENTIAL from an unaware write() system call, and receiver not using SO_PASSCRED socket option. If SOCK_PASSCRED is set on source or destination socket, we still include credentials for mere write() syscalls. Performance boost in hackbench : more than 50% gain on a 16 thread machine (2 quad-core cpus, 2 threads per core) hackbench 20 thread 2000 4.228 sec instead of 9.102 sec Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com> Acked-by: NTim Chen <tim.c.chen@linux.intel.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 17 9月, 2011 1 次提交
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由 David S. Miller 提交于
This reverts commit 0856a304. As requested by Eric Dumazet, it has various ref-counting problems and has introduced regressions. Eric will add a more suitable version of this performance fix. Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 25 8月, 2011 1 次提交
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由 Tim Chen 提交于
Patch series 109f6e39..7361c36c back in 2.6.36 added functionality to allow credentials to work across pid namespaces for packets sent via UNIX sockets. However, the atomic reference counts on pid and credentials caused plenty of cache bouncing when there are numerous threads of the same pid sharing a UNIX socket. This patch mitigates the problem by eliminating extraneous reference counts on pid and credentials on both send and receive path of UNIX sockets. I found a 2x improvement in hackbench's threaded case. On the receive path in unix_dgram_recvmsg, currently there is an increment of reference count on pid and credentials in scm_set_cred. Then there are two decrement of the reference counts. Once in scm_recv and once when skb_free_datagram call skb->destructor function unix_destruct_scm. One pair of increment and decrement of ref count on pid and credentials can be eliminated from the receive path. Until we destroy the skb, we already set a reference when we created the skb on the send side. On the send path, there are two increments of ref count on pid and credentials, once in scm_send and once in unix_scm_to_skb. Then there is a decrement of the reference counts in scm_destroy's call to scm_destroy_cred at the end of unix_dgram_sendmsg functions. One pair of increment and decrement of the reference counts can be removed so we only need to increment the ref counts once. By incorporating these changes, for hackbench running on a 4 socket NHM-EX machine with 40 cores, the execution of hackbench on 50 groups of 20 threads sped up by factor of 2. Hackbench command used for testing: ./hackbench 50 thread 2000 Signed-off-by: NTim Chen <tim.c.chen@linux.intel.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 20 7月, 2011 1 次提交
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由 Al Viro 提交于
combination of kern_path_parent() and lookup_create(). Does *not* expose struct nameidata to caller. Syscalls converted to that... Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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- 24 5月, 2011 1 次提交
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由 Dan Rosenberg 提交于
The %pK format specifier is designed to hide exposed kernel pointers, specifically via /proc interfaces. Exposing these pointers provides an easy target for kernel write vulnerabilities, since they reveal the locations of writable structures containing easily triggerable function pointers. The behavior of %pK depends on the kptr_restrict sysctl. If kptr_restrict is set to 0, no deviation from the standard %p behavior occurs. If kptr_restrict is set to 1, the default, if the current user (intended to be a reader via seq_printf(), etc.) does not have CAP_SYSLOG (currently in the LSM tree), kernel pointers using %pK are printed as 0's. If kptr_restrict is set to 2, kernel pointers using %pK are printed as 0's regardless of privileges. Replacing with 0's was chosen over the default "(null)", which cannot be parsed by userland %p, which expects "(nil)". The supporting code for kptr_restrict and %pK are currently in the -mm tree. This patch converts users of %p in net/ to %pK. Cases of printing pointers to the syslog are not covered, since this would eliminate useful information for postmortem debugging and the reading of the syslog is already optionally protected by the dmesg_restrict sysctl. Signed-off-by: NDan Rosenberg <drosenberg@vsecurity.com> Cc: James Morris <jmorris@namei.org> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Thomas Graf <tgraf@infradead.org> Cc: Eugene Teo <eugeneteo@kernel.org> Cc: Kees Cook <kees.cook@canonical.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: David S. Miller <davem@davemloft.net> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Eric Paris <eparis@parisplace.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 02 5月, 2011 1 次提交
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由 Eric W. Biederman 提交于
This fixes the following oops discovered by Dan Aloni: > Anyway, the following is the output of the Oops that I got on the > Ubuntu kernel on which I first detected the problem > (2.6.37-12-generic). The Oops that followed will be more useful, I > guess. >[ 5594.669852] BUG: unable to handle kernel NULL pointer dereference > at (null) > [ 5594.681606] IP: [<ffffffff81550b7b>] unix_dgram_recvmsg+0x1fb/0x420 > [ 5594.687576] PGD 2a05d067 PUD 2b951067 PMD 0 > [ 5594.693720] Oops: 0002 [#1] SMP > [ 5594.699888] last sysfs file: The bug was that unix domain sockets use a pseduo packet for connecting and accept uses that psudo packet to get the socket. In the buggy seqpacket case we were allowing unconnected sockets to call recvmsg and try to receive the pseudo packet. That is always wrong and as of commit 7361c36c the pseudo packet had become enough different from a normal packet that the kernel started oopsing. Do for seqpacket_recv what was done for seqpacket_send in 2.5 and only allow it on connected seqpacket sockets. Cc: stable@kernel.org Tested-by: NDan Aloni <dan@aloni.org> Signed-off-by: NEric W. Biederman <ebiederm@xmission.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 31 3月, 2011 1 次提交
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由 Lucas De Marchi 提交于
Fixes generated by 'codespell' and manually reviewed. Signed-off-by: NLucas De Marchi <lucas.demarchi@profusion.mobi>
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- 15 3月, 2011 1 次提交
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由 Daniel Baluta 提交于
We latch our state using a spinlock not a r/w kind of lock. Signed-off-by: NDaniel Baluta <dbaluta@ixiacom.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 14 3月, 2011 1 次提交
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由 Al Viro 提交于
all remaining callers pass LOOKUP_PARENT to it, so flags argument can die; renamed to kern_path_parent() Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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- 08 3月, 2011 2 次提交
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由 Hagen Paul Pfeifer 提交于
Signed-off-by: NHagen Paul Pfeifer <hagen@jauu.net> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Rainer Weikusat 提交于
The unix_dgram_recvmsg and unix_stream_recvmsg routines in net/af_unix.c utilize mutex_lock(&u->readlock) calls in order to serialize read operations of multiple threads on a single socket. This implies that, if all n threads of a process block in an AF_UNIX recv call trying to read data from the same socket, one of these threads will be sleeping in state TASK_INTERRUPTIBLE and all others in state TASK_UNINTERRUPTIBLE. Provided that a particular signal is supposed to be handled by a signal handler defined by the process and that none of this threads is blocking the signal, the complete_signal routine in kernel/signal.c will select the 'first' such thread it happens to encounter when deciding which thread to notify that a signal is supposed to be handled and if this is one of the TASK_UNINTERRUPTIBLE threads, the signal won't be handled until the one thread not blocking on the u->readlock mutex is woken up because some data to process has arrived (if this ever happens). The included patch fixes this by changing mutex_lock to mutex_lock_interruptible and handling possible error returns in the same way interruptions are handled by the actual receive-code. Signed-off-by: NRainer Weikusat <rweikusat@mobileactivedefense.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 23 2月, 2011 1 次提交
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由 Eric Dumazet 提交于
Add proper RCU annotations/verbs to sk_wq and wq members Fix __sctp_write_space() sk_sleep() abuse (and sock->wq access) Fix sunrpc sk_sleep() abuse too Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 20 1月, 2011 1 次提交
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由 Alban Crequy 提交于
Signed-off-by: NAlban Crequy <alban.crequy@collabora.co.uk> Reviewed-by: NIan Molton <ian.molton@collabora.co.uk> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 19 1月, 2011 1 次提交
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由 Alban Crequy 提交于
Linux Socket Filters can already be successfully attached and detached on unix sockets with setsockopt(sockfd, SOL_SOCKET, SO_{ATTACH,DETACH}_FILTER, ...). See: Documentation/networking/filter.txt But the filter was never used in the unix socket code so it did not work. This patch uses sk_filter() to filter buffers before delivery. This short program demonstrates the problem on SOCK_DGRAM. int main(void) { int i, j, ret; int sv[2]; struct pollfd fds[2]; char *message = "Hello world!"; char buffer[64]; struct sock_filter ins[32] = {{0,},}; struct sock_fprog filter; socketpair(AF_UNIX, SOCK_DGRAM, 0, sv); for (i = 0 ; i < 2 ; i++) { fds[i].fd = sv[i]; fds[i].events = POLLIN; fds[i].revents = 0; } for(j = 1 ; j < 13 ; j++) { /* Set a socket filter to truncate the message */ memset(ins, 0, sizeof(ins)); ins[0].code = BPF_RET|BPF_K; ins[0].k = j; filter.len = 1; filter.filter = ins; setsockopt(sv[1], SOL_SOCKET, SO_ATTACH_FILTER, &filter, sizeof(filter)); /* send a message */ send(sv[0], message, strlen(message) + 1, 0); /* The filter should let the message pass but truncated. */ poll(fds, 2, 0); /* Receive the truncated message*/ ret = recv(sv[1], buffer, 64, 0); printf("received %d bytes, expected %d\n", ret, j); } for (i = 0 ; i < 2 ; i++) close(sv[i]); return 0; } Signed-off-by: NAlban Crequy <alban.crequy@collabora.co.uk> Reviewed-by: NIan Molton <ian.molton@collabora.co.uk> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 06 1月, 2011 1 次提交
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由 David S. Miller 提交于
unix_release() can asynchornously set socket->sk to NULL, and it does so without holding the unix_state_lock() on "other" during stream connects. However, the reverse mapping, sk->sk_socket, is only transitioned to NULL under the unix_state_lock(). Therefore make the security hooks follow the reverse mapping instead of the forward mapping. Reported-by: NJeremy Fitzhardinge <jeremy@goop.org> Reported-by: NLinus Torvalds <torvalds@linux-foundation.org> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 30 11月, 2010 1 次提交
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由 Eric Dumazet 提交于
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: NМарк Коренберг <socketpair@gmail.com> Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 09 11月, 2010 3 次提交
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由 Eric Dumazet 提交于
unix_dgram_poll() is pretty expensive to check POLLOUT status, because it has to lock the socket to get its peer, take a reference on the peer to check its receive queue status, and queue another poll_wait on peer_wait. This all can be avoided if the process calling unix_dgram_poll() is not interested in POLLOUT status. It makes unix_dgram_recvmsg() faster by not queueing irrelevant pollers in peer_wait. On a test program provided by Alan Crequy : Before: real 0m0.211s user 0m0.000s sys 0m0.208s After: real 0m0.044s user 0m0.000s sys 0m0.040s Suggested-by: NDavide Libenzi <davidel@xmailserver.org> Reported-by: NAlban Crequy <alban.crequy@collabora.co.uk> Acked-by: NDavide Libenzi <davidel@xmailserver.org> Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Eric Dumazet 提交于
Alban Crequy reported a problem with connected dgram af_unix sockets and provided a test program. epoll() would miss to send an EPOLLOUT event when a thread unqueues a packet from the other peer, making its receive queue not full. This is because unix_dgram_poll() fails to call sock_poll_wait(file, &unix_sk(other)->peer_wait, wait); if the socket is not writeable at the time epoll_ctl(ADD) is called. We must call sock_poll_wait(), regardless of 'writable' status, so that epoll can be notified later of states changes. Misc: avoids testing twice (sk->sk_shutdown & RCV_SHUTDOWN) Reported-by: NAlban Crequy <alban.crequy@collabora.co.uk> Cc: Davide Libenzi <davidel@xmailserver.org> Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com> Acked-by: NDavide Libenzi <davidel@xmailserver.org> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Eric Dumazet 提交于
Instead of wakeup all sleepers, use wake_up_interruptible_sync_poll() to wakeup only ones interested into writing the socket. This patch is a specialization of commit 37e5540b (epoll keyed wakeups: make sockets use keyed wakeups). On a test program provided by Alan Crequy : Before: real 0m3.101s user 0m0.000s sys 0m6.104s After: real 0m0.211s user 0m0.000s sys 0m0.208s Reported-by: NAlban Crequy <alban.crequy@collabora.co.uk> Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com> Cc: Davide Libenzi <davidel@xmailserver.org> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 27 10月, 2010 1 次提交
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由 Eric Dumazet 提交于
Robin Holt tried to boot a 16TB system and found af_unix was overflowing a 32bit value : <quote> We were seeing a failure which prevented boot. The kernel was incapable of creating either a named pipe or unix domain socket. This comes down to a common kernel function called unix_create1() which does: atomic_inc(&unix_nr_socks); if (atomic_read(&unix_nr_socks) > 2 * get_max_files()) goto out; The function get_max_files() is a simple return of files_stat.max_files. files_stat.max_files is a signed integer and is computed in fs/file_table.c's files_init(). n = (mempages * (PAGE_SIZE / 1024)) / 10; files_stat.max_files = n; In our case, mempages (total_ram_pages) is approx 3,758,096,384 (0xe0000000). That leaves max_files at approximately 1,503,238,553. This causes 2 * get_max_files() to integer overflow. </quote> Fix is to let /proc/sys/fs/file-nr & /proc/sys/fs/file-max use long integers, and change af_unix to use an atomic_long_t instead of atomic_t. get_max_files() is changed to return an unsigned long. get_nr_files() is changed to return a long. unix_nr_socks is changed from atomic_t to atomic_long_t, while not strictly needed to address Robin problem. Before patch (on a 64bit kernel) : # echo 2147483648 >/proc/sys/fs/file-max # cat /proc/sys/fs/file-max -18446744071562067968 After patch: # echo 2147483648 >/proc/sys/fs/file-max # cat /proc/sys/fs/file-max 2147483648 # cat /proc/sys/fs/file-nr 704 0 2147483648 Reported-by: NRobin Holt <holt@sgi.com> Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com> Acked-by: NDavid Miller <davem@davemloft.net> Reviewed-by: NRobin Holt <holt@sgi.com> Tested-by: NRobin Holt <holt@sgi.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 26 10月, 2010 1 次提交
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由 Eric Dumazet 提交于
Andrew, Could you please review this patch, you probably are the right guy to take it, because it crosses fs and net trees. Note : /proc/sys/fs/file-nr is a read-only file, so this patch doesnt depend on previous patch (sysctl: fix min/max handling in __do_proc_doulongvec_minmax()) Thanks ! [PATCH V4] fs: allow for more than 2^31 files Robin Holt tried to boot a 16TB system and found af_unix was overflowing a 32bit value : <quote> We were seeing a failure which prevented boot. The kernel was incapable of creating either a named pipe or unix domain socket. This comes down to a common kernel function called unix_create1() which does: atomic_inc(&unix_nr_socks); if (atomic_read(&unix_nr_socks) > 2 * get_max_files()) goto out; The function get_max_files() is a simple return of files_stat.max_files. files_stat.max_files is a signed integer and is computed in fs/file_table.c's files_init(). n = (mempages * (PAGE_SIZE / 1024)) / 10; files_stat.max_files = n; In our case, mempages (total_ram_pages) is approx 3,758,096,384 (0xe0000000). That leaves max_files at approximately 1,503,238,553. This causes 2 * get_max_files() to integer overflow. </quote> Fix is to let /proc/sys/fs/file-nr & /proc/sys/fs/file-max use long integers, and change af_unix to use an atomic_long_t instead of atomic_t. get_max_files() is changed to return an unsigned long. get_nr_files() is changed to return a long. unix_nr_socks is changed from atomic_t to atomic_long_t, while not strictly needed to address Robin problem. Before patch (on a 64bit kernel) : # echo 2147483648 >/proc/sys/fs/file-max # cat /proc/sys/fs/file-max -18446744071562067968 After patch: # echo 2147483648 >/proc/sys/fs/file-max # cat /proc/sys/fs/file-max 2147483648 # cat /proc/sys/fs/file-nr 704 0 2147483648 Reported-by: NRobin Holt <holt@sgi.com> Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com> Acked-by: NDavid Miller <davem@davemloft.net> Reviewed-by: NRobin Holt <holt@sgi.com> Tested-by: NRobin Holt <holt@sgi.com> Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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