linux-stable.git/net/netlink, branch v4.14.2 Linux kernel stable tree af_netlink: ensure that NLMSG_DONE never fails in dumps 2017-11-24T07:37:03+00:00 Jason A. Donenfeld Jason@zx2c4.com 2017-11-09T04:04:44+00:00 5856c858c6eaa9a4ba2100a9c7f1748be5614546 [ Upstream commit 0642840b8bb008528dbdf929cec9f65ac4231ad0 ] The way people generally use netlink_dump is that they fill in the skb as much as possible, breaking when nla_put returns an error. Then, they get called again and start filling out the next skb, and again, and so forth. The mechanism at work here is the ability for the iterative dumping function to detect when the skb is filled up and not fill it past the brim, waiting for a fresh skb for the rest of the data. However, if the attributes are small and nicely packed, it is possible that a dump callback function successfully fills in attributes until the skb is of size 4080 (libmnl's default page-sized receive buffer size). The dump function completes, satisfied, and then, if it happens to be that this is actually the last skb, and no further ones are to be sent, then netlink_dump will add on the NLMSG_DONE part: nlh = nlmsg_put_answer(skb, cb, NLMSG_DONE, sizeof(len), NLM_F_MULTI); It is very important that netlink_dump does this, of course. However, in this example, that call to nlmsg_put_answer will fail, because the previous filling by the dump function did not leave it enough room. And how could it possibly have done so? All of the nla_put variety of functions simply check to see if the skb has enough tailroom, independent of the context it is in. In order to keep the important assumptions of all netlink dump users, it is therefore important to give them an skb that has this end part of the tail already reserved, so that the call to nlmsg_put_answer does not fail. Otherwise, library authors are forced to find some bizarre sized receive buffer that has a large modulo relative to the common sizes of messages received, which is ugly and buggy. This patch thus saves the NLMSG_DONE for an additional message, for the case that things are dangerously close to the brim. This requires keeping track of the errno from ->dump() across calls. Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 0642840b8bb008528dbdf929cec9f65ac4231ad0 ]

The way people generally use netlink_dump is that they fill in the skb
as much as possible, breaking when nla_put returns an error. Then, they
get called again and start filling out the next skb, and again, and so
forth. The mechanism at work here is the ability for the iterative
dumping function to detect when the skb is filled up and not fill it
past the brim, waiting for a fresh skb for the rest of the data.

However, if the attributes are small and nicely packed, it is possible
that a dump callback function successfully fills in attributes until the
skb is of size 4080 (libmnl's default page-sized receive buffer size).
The dump function completes, satisfied, and then, if it happens to be
that this is actually the last skb, and no further ones are to be sent,
then netlink_dump will add on the NLMSG_DONE part:

  nlh = nlmsg_put_answer(skb, cb, NLMSG_DONE, sizeof(len), NLM_F_MULTI);

It is very important that netlink_dump does this, of course. However, in
this example, that call to nlmsg_put_answer will fail, because the
previous filling by the dump function did not leave it enough room. And
how could it possibly have done so? All of the nla_put variety of
functions simply check to see if the skb has enough tailroom,
independent of the context it is in.

In order to keep the important assumptions of all netlink dump users, it
is therefore important to give them an skb that has this end part of the
tail already reserved, so that the call to nlmsg_put_answer does not
fail. Otherwise, library authors are forced to find some bizarre sized
receive buffer that has a large modulo relative to the common sizes of
messages received, which is ugly and buggy.

This patch thus saves the NLMSG_DONE for an additional message, for the
case that things are dangerously close to the brim. This requires
keeping track of the errno from ->dump() across calls.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02T10:10:55+00:00 Greg Kroah-Hartman gregkh@linuxfoundation.org 2017-11-01T14:07:57+00:00 b24413180f5600bcb3bb70fbed5cf186b60864bd 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> 
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>
netlink: fix netlink_ack() extack race 2017-10-18T11:22:28+00:00 Johannes Berg johannes.berg@intel.com 2017-10-16T15:09:53+00:00 48044eb490be71c203e14dd89e8bae87209eab52 It seems that it's possible to toggle NETLINK_F_EXT_ACK through setsockopt() while another thread/CPU is building a message inside netlink_ack(), which could then trigger the WARN_ON()s I added since if it goes from being turned off to being turned on between allocating and filling the message, the skb could end up being too small. Avoid this whole situation by storing the value of this flag in a separate variable and using that throughout the function instead. Fixes: 2d4bc93368f5 ("netlink: extended ACK reporting") Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
It seems that it's possible to toggle NETLINK_F_EXT_ACK
through setsockopt() while another thread/CPU is building
a message inside netlink_ack(), which could then trigger
the WARN_ON()s I added since if it goes from being turned
off to being turned on between allocating and filling the
message, the skb could end up being too small.

Avoid this whole situation by storing the value of this
flag in a separate variable and using that throughout the
function instead.

Fixes: 2d4bc93368f5 ("netlink: extended ACK reporting")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
netlink: do not set cb_running if dump's start() errs 2017-10-09T17:27:49+00:00 Jason A. Donenfeld Jason@zx2c4.com 2017-10-09T12:14:51+00:00 41c87425a1ac9b633e0fcc78eb1f19640c8fb5a0 It turns out that multiple places can call netlink_dump(), which means it's still possible to dereference partially initialized values in dump() that were the result of a faulty returned start(). This fixes the issue by calling start() _before_ setting cb_running to true, so that there's no chance at all of hitting the dump() function through any indirect paths. It also moves the call to start() to be when the mutex is held. This has the nice side effect of serializing invocations to start(), which is likely desirable anyway. It also prevents any possible other races that might come out of this logic. In testing this with several different pieces of tricky code to trigger these issues, this commit fixes all avenues that I'm aware of. Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Cc: Johannes Berg <johannes@sipsolutions.net> Reviewed-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: David S. Miller <davem@davemloft.net> 
It turns out that multiple places can call netlink_dump(), which means
it's still possible to dereference partially initialized values in
dump() that were the result of a faulty returned start().

This fixes the issue by calling start() _before_ setting cb_running to
true, so that there's no chance at all of hitting the dump() function
through any indirect paths.

It also moves the call to start() to be when the mutex is held. This has
the nice side effect of serializing invocations to start(), which is
likely desirable anyway. It also prevents any possible other races that
might come out of this logic.

In testing this with several different pieces of tricky code to trigger
these issues, this commit fixes all avenues that I'm aware of.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
netlink: do not proceed if dump's start() errs 2017-09-30T15:13:31+00:00 Jason A. Donenfeld Jason@zx2c4.com 2017-09-27T22:41:44+00:00 fef0035c0f31322d417d1954bba5ab959bf91183 Drivers that use the start method for netlink dumping rely on dumpit not being called if start fails. For example, ila_xlat.c allocates memory and assigns it to cb->args[0] in its start() function. It might fail to do that and return -ENOMEM instead. However, even when returning an error, dumpit will be called, which, in the example above, quickly dereferences the memory in cb->args[0], which will OOPS the kernel. This is but one example of how this goes wrong. Since start() has always been a function with an int return type, it therefore makes sense to use it properly, rather than ignoring it. This patch thus returns early and does not call dumpit() when start() fails. Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Cc: Johannes Berg <johannes@sipsolutions.net> Reviewed-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: David S. Miller <davem@davemloft.net> 
Drivers that use the start method for netlink dumping rely on dumpit not
being called if start fails. For example, ila_xlat.c allocates memory
and assigns it to cb->args[0] in its start() function. It might fail to
do that and return -ENOMEM instead. However, even when returning an
error, dumpit will be called, which, in the example above, quickly
dereferences the memory in cb->args[0], which will OOPS the kernel. This
is but one example of how this goes wrong.

Since start() has always been a function with an int return type, it
therefore makes sense to use it properly, rather than ignoring it. This
patch thus returns early and does not call dumpit() when start() fails.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
netlink: access nlk groups safely in netlink bind and getname 2017-09-07T04:22:54+00:00 Xin Long lucien.xin@gmail.com 2017-09-06T03:53:29+00:00 f773608026ee1e75e2256e3ad625c222ff6f9305 Now there is no lock protecting nlk ngroups/groups' accessing in netlink bind and getname. It's safe from nlk groups' setting in netlink_release, but not from netlink_realloc_groups called by netlink_setsockopt. netlink_lock_table is needed in both netlink bind and getname when accessing nlk groups. Acked-by: Florian Westphal <fw@strlen.de> Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Now there is no lock protecting nlk ngroups/groups' accessing in
netlink bind and getname. It's safe from nlk groups' setting in
netlink_release, but not from netlink_realloc_groups called by
netlink_setsockopt.

netlink_lock_table is needed in both netlink bind and getname when
accessing nlk groups.

Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
netlink: fix an use-after-free issue for nlk groups 2017-09-07T04:22:53+00:00 Xin Long lucien.xin@gmail.com 2017-09-06T03:47:12+00:00 be82485fbcbb1cf11b13e7356231c72fdf21241c ChunYu found a netlink use-after-free issue by syzkaller: [28448.842981] BUG: KASAN: use-after-free in __nla_put+0x37/0x40 at addr ffff8807185e2378 [28448.969918] Call Trace: [...] [28449.117207] __nla_put+0x37/0x40 [28449.132027] nla_put+0xf5/0x130 [28449.146261] sk_diag_fill.isra.4.constprop.5+0x5a0/0x750 [netlink_diag] [28449.176608] __netlink_diag_dump+0x25a/0x700 [netlink_diag] [28449.202215] netlink_diag_dump+0x176/0x240 [netlink_diag] [28449.226834] netlink_dump+0x488/0xbb0 [28449.298014] __netlink_dump_start+0x4e8/0x760 [28449.317924] netlink_diag_handler_dump+0x261/0x340 [netlink_diag] [28449.413414] sock_diag_rcv_msg+0x207/0x390 [28449.432409] netlink_rcv_skb+0x149/0x380 [28449.467647] sock_diag_rcv+0x2d/0x40 [28449.484362] netlink_unicast+0x562/0x7b0 [28449.564790] netlink_sendmsg+0xaa8/0xe60 [28449.661510] sock_sendmsg+0xcf/0x110 [28449.865631] __sys_sendmsg+0xf3/0x240 [28450.000964] SyS_sendmsg+0x32/0x50 [28450.016969] do_syscall_64+0x25c/0x6c0 [28450.154439] entry_SYSCALL64_slow_path+0x25/0x25 It was caused by no protection between nlk groups' free in netlink_release and nlk groups' accessing in sk_diag_dump_groups. The similar issue also exists in netlink_seq_show(). This patch is to defer nlk groups' free in deferred_put_nlk_sk. Reported-by: ChunYu Wang <chunwang@redhat.com> Acked-by: Florian Westphal <fw@strlen.de> Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
ChunYu found a netlink use-after-free issue by syzkaller:

[28448.842981] BUG: KASAN: use-after-free in __nla_put+0x37/0x40 at addr ffff8807185e2378
[28448.969918] Call Trace:
[...]
[28449.117207]  __nla_put+0x37/0x40
[28449.132027]  nla_put+0xf5/0x130
[28449.146261]  sk_diag_fill.isra.4.constprop.5+0x5a0/0x750 [netlink_diag]
[28449.176608]  __netlink_diag_dump+0x25a/0x700 [netlink_diag]
[28449.202215]  netlink_diag_dump+0x176/0x240 [netlink_diag]
[28449.226834]  netlink_dump+0x488/0xbb0
[28449.298014]  __netlink_dump_start+0x4e8/0x760
[28449.317924]  netlink_diag_handler_dump+0x261/0x340 [netlink_diag]
[28449.413414]  sock_diag_rcv_msg+0x207/0x390
[28449.432409]  netlink_rcv_skb+0x149/0x380
[28449.467647]  sock_diag_rcv+0x2d/0x40
[28449.484362]  netlink_unicast+0x562/0x7b0
[28449.564790]  netlink_sendmsg+0xaa8/0xe60
[28449.661510]  sock_sendmsg+0xcf/0x110
[28449.865631]  __sys_sendmsg+0xf3/0x240
[28450.000964]  SyS_sendmsg+0x32/0x50
[28450.016969]  do_syscall_64+0x25c/0x6c0
[28450.154439]  entry_SYSCALL64_slow_path+0x25/0x25

It was caused by no protection between nlk groups' free in netlink_release
and nlk groups' accessing in sk_diag_dump_groups. The similar issue also
exists in netlink_seq_show().

This patch is to defer nlk groups' free in deferred_put_nlk_sk.

Reported-by: ChunYu Wang <chunwang@redhat.com>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: convert sock.sk_refcnt from atomic_t to refcount_t 2017-07-01T14:39:08+00:00 Reshetova, Elena elena.reshetova@intel.com 2017-06-30T10:08:01+00:00 41c6d650f6537e55a1b53438c646fbc3f49176bf refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. This patch uses refcount_inc_not_zero() instead of atomic_inc_not_zero_hint() due to absense of a _hint() version of refcount API. If the hint() version must be used, we might need to revisit API. Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David Windsor <dwindsor@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

This patch uses refcount_inc_not_zero() instead of
atomic_inc_not_zero_hint() due to absense of a _hint()
version of refcount API. If the hint() version must
be used, we might need to revisit API.

Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: convert sock.sk_wmem_alloc from atomic_t to refcount_t 2017-07-01T14:39:08+00:00 Reshetova, Elena elena.reshetova@intel.com 2017-06-30T10:08:00+00:00 14afee4b6092fde451ee17604e5f5c89da33e71e 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> 
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>
net: convert sk_buff.users from atomic_t to refcount_t 2017-07-01T14:39:07+00:00 Reshetova, Elena elena.reshetova@intel.com 2017-06-30T10:07:58+00:00 633547973ffc32fd2c815639d4675e1531f0896f 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> 
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>