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David S. Miller 307201a3d4 Merge branch 'cls_u32-fix-refcount-leak'
Davide Caratti says:

====================
net/sched: cls_u32: fix refcount leak

a refcount leak in the error path of u32_change() has been recently
introduced. It can be observed with the following commands:

  [root@f31 ~]# tc filter replace dev eth0 ingress protocol ip prio 97 \
  > u32 match ip src 127.0.0.1/32 indev notexist20 flowid 1:1 action drop
  RTNETLINK answers: Invalid argument
  We have an error talking to the kernel
  [root@f31 ~]# tc filter replace dev eth0 ingress protocol ip prio 98 \
  > handle 42:42 u32 divisor 256
  Error: cls_u32: Divisor can only be used on a hash table.
  We have an error talking to the kernel
  [root@f31 ~]# tc filter replace dev eth0 ingress protocol ip prio 99 \
  > u32 ht 47:47
  Error: cls_u32: Specified hash table not found.
  We have an error talking to the kernel

they all legitimately return -EINVAL; however, they leave semi-configured
filters at eth0 tc ingress:

 [root@f31 ~]# tc filter show dev eth0 ingress
 filter protocol ip pref 97 u32 chain 0
 filter protocol ip pref 97 u32 chain 0 fh 800: ht divisor 1
 filter protocol ip pref 98 u32 chain 0
 filter protocol ip pref 98 u32 chain 0 fh 801: ht divisor 1
 filter protocol ip pref 99 u32 chain 0
 filter protocol ip pref 99 u32 chain 0 fh 802: ht divisor 1

With older kernels, filters were unconditionally considered empty (and
thus de-refcounted) on the error path of ->change().
After commit 8b64678e0a ("net: sched: refactor tp insert/delete for
concurrent execution"), filters were considered empty when the walk()
function didn't set 'walker.stop' to 1.
Finally, with commit 6676d5e416 ("net: sched: set dedicated tcf_walker
flag when tp is empty"), tc filters are considered empty unless the walker
function is called with a non-NULL handle. This last change doesn't fit
cls_u32 design, because at least the "root hnode" is (almost) always
non-NULL, as it's allocated in u32_init().

- patch 1/2 is a proposal to restore the original kernel behavior, where
  no filter was installed in the error path of u32_change().
- patch 2/2 adds tdc selftests that can be ued to verify the correct
  behavior of u32 in the error path of ->change().
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-19 17:53:05 -08:00
arch bpf, mips: Limit to 33 tail calls 2019-12-11 13:57:22 +01:00
block block: fix memleak of bio integrity data 2019-12-05 11:38:36 -07:00
certs certs: Add wrapper function to check blacklisted binary hash 2019-11-12 12:25:50 +11:00
crypto Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2019-11-25 19:49:58 -08:00
Documentation linux-can-fixes-for-5.5-20191208 2019-12-09 09:27:47 -08:00
drivers nfc: s3fwrn5: replace the assertion with a WARN_ON 2019-12-19 17:33:23 -08:00
fs 9 cifs/smb3 fixes: two timestamp fixes, one oops fix (during oplock break) for stable, two fixes found in multichannel testing, two fixes for file create when using modeforsid mount parm 2019-12-08 12:12:18 -08:00
include of: mdio: export of_mdiobus_child_is_phy 2019-12-19 17:32:21 -08:00
init init/Kconfig: fix indentation 2019-12-04 19:44:13 -08:00
ipc y2038: remove CONFIG_64BIT_TIME 2019-11-15 14:38:27 +01:00
kernel bpf: Fix record_func_key to perform backtracking on r3 2019-12-19 13:39:22 -08:00
lib lib/: fix Kconfig indentation 2019-12-07 11:00:19 -08:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
mm Merge branch 'akpm' (patches from Andrew) 2019-12-05 09:46:26 -08:00
net net/sched: cls_u32: fix refcount leak in the error path of u32_change() 2019-12-19 17:53:05 -08:00
samples samples: bpf: fix syscall_tp due to unused syscall 2019-12-11 15:28:06 -08:00
scripts Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-12-08 13:28:11 -08:00
security + Features 2019-12-03 12:51:35 -08:00
sound sound updates #2 for 5.5-rc1 2019-12-06 13:06:14 -08:00
tools tc-testing: initial tdc selftests for cls_u32 2019-12-19 17:53:05 -08:00
usr arch: sembuf.h: make uapi asm/sembuf.h self-contained 2019-12-04 19:44:14 -08:00
virt KVM: Fix jump label out_free_* in kvm_init() 2019-11-23 11:29:17 +01:00
.clang-format clang-format: Update with the latest for_each macro list 2019-08-31 10:00:51 +02:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore modpost: dump missing namespaces into a single modules.nsdeps file 2019-11-11 20:10:01 +09:00
.mailmap mailmap: add entry for myself 2019-12-13 15:15:33 -08:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS Linux 5.4-rc4 2019-10-29 04:43:29 -06:00
Kbuild kbuild: do not descend to ./Kbuild when cleaning 2019-08-21 21:03:58 +09:00
Kconfig docs: kbuild: convert docs to ReST and rename to *.rst 2019-06-14 14:21:21 -06:00
MAINTAINERS MAINTAINERS: Add maintainers for rmnet 2019-12-13 15:14:24 -08:00
Makefile Linux 5.5-rc1 2019-12-08 14:57:55 -08:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.