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Kuniyuki Iwashima 0c5d628f1e tcp/udp: Fix memory leak in ipv6_renew_options().
commit 3c52c6bb83 upstream.

syzbot reported a memory leak [0] related to IPV6_ADDRFORM.

The scenario is that while one thread is converting an IPv6 socket into
IPv4 with IPV6_ADDRFORM, another thread calls do_ipv6_setsockopt() and
allocates memory to inet6_sk(sk)->XXX after conversion.

Then, the converted sk with (tcp|udp)_prot never frees the IPv6 resources,
which inet6_destroy_sock() should have cleaned up.

setsockopt(IPV6_ADDRFORM)                 setsockopt(IPV6_DSTOPTS)
+-----------------------+                 +----------------------+
- do_ipv6_setsockopt(sk, ...)
  - sockopt_lock_sock(sk)                 - do_ipv6_setsockopt(sk, ...)
    - lock_sock(sk)                         ^._ called via tcpv6_prot
  - WRITE_ONCE(sk->sk_prot, &tcp_prot)          before WRITE_ONCE()
  - xchg(&np->opt, NULL)
  - txopt_put(opt)
  - sockopt_release_sock(sk)
    - release_sock(sk)                      - sockopt_lock_sock(sk)
                                              - lock_sock(sk)
                                            - ipv6_set_opt_hdr(sk, ...)
                                              - ipv6_update_options(sk, opt)
                                                - xchg(&inet6_sk(sk)->opt, opt)
                                                  ^._ opt is never freed.

                                            - sockopt_release_sock(sk)
                                              - release_sock(sk)

Since IPV6_DSTOPTS allocates options under lock_sock(), we can avoid this
memory leak by testing whether sk_family is changed by IPV6_ADDRFORM after
acquiring the lock.

This issue exists from the initial commit between IPV6_ADDRFORM and
IPV6_PKTOPTIONS.

[0]:
BUG: memory leak
unreferenced object 0xffff888009ab9f80 (size 96):
  comm "syz-executor583", pid 328, jiffies 4294916198 (age 13.034s)
  hex dump (first 32 bytes):
    01 00 00 00 48 00 00 00 08 00 00 00 00 00 00 00  ....H...........
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<000000002ee98ae1>] kmalloc include/linux/slab.h:605 [inline]
    [<000000002ee98ae1>] sock_kmalloc+0xb3/0x100 net/core/sock.c:2566
    [<0000000065d7b698>] ipv6_renew_options+0x21e/0x10b0 net/ipv6/exthdrs.c:1318
    [<00000000a8c756d7>] ipv6_set_opt_hdr net/ipv6/ipv6_sockglue.c:354 [inline]
    [<00000000a8c756d7>] do_ipv6_setsockopt.constprop.0+0x28b7/0x4350 net/ipv6/ipv6_sockglue.c:668
    [<000000002854d204>] ipv6_setsockopt+0xdf/0x190 net/ipv6/ipv6_sockglue.c:1021
    [<00000000e69fdcf8>] tcp_setsockopt+0x13b/0x2620 net/ipv4/tcp.c:3789
    [<0000000090da4b9b>] __sys_setsockopt+0x239/0x620 net/socket.c:2252
    [<00000000b10d192f>] __do_sys_setsockopt net/socket.c:2263 [inline]
    [<00000000b10d192f>] __se_sys_setsockopt net/socket.c:2260 [inline]
    [<00000000b10d192f>] __x64_sys_setsockopt+0xbe/0x160 net/socket.c:2260
    [<000000000a80d7aa>] do_syscall_x64 arch/x86/entry/common.c:50 [inline]
    [<000000000a80d7aa>] do_syscall_64+0x38/0x90 arch/x86/entry/common.c:80
    [<000000004562b5c6>] entry_SYSCALL_64_after_hwframe+0x63/0xcd

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Meena Shanmugam <meenashanmugam@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-04 00:00:35 +09:00
Documentation Revert "dt-bindings: pinctrl-zynqmp: Add output-enable configuration" 2022-11-04 00:00:24 +09:00
LICENSES LICENSES/LGPL-2.1: Add LGPL-2.1-or-later as valid identifiers 2021-12-16 14:33:10 +01:00
arch arm64: Add AMPERE1 to the Spectre-BHB affected list 2022-11-04 00:00:35 +09:00
block blk-mq: fix null pointer dereference in blk_mq_clear_rq_mapping() 2022-10-29 10:08:33 +02:00
certs certs: make system keyring depend on built-in x509 parser 2022-09-24 04:31:18 +09:00
crypto crypto: akcipher - default implementation for setting a private key 2022-10-21 12:38:59 +02:00
drivers net: enetc: survive memory pressure without crashing 2022-11-04 00:00:34 +09:00
fs erofs: fix up inplace decompression success rate 2022-11-04 00:00:27 +09:00
include net/mlx5: Fix possible use-after-free in async command interface 2022-11-04 00:00:34 +09:00
init arm64 fixes for -rc3 2022-08-26 11:32:53 -07:00
io_uring io_uring: don't gate task_work run on TIF_NOTIFY_SIGNAL 2022-10-29 10:08:35 +02:00
ipc ipc: mqueue: fix possible memory leak in init_mqueue_fs() 2022-10-21 12:38:55 +02:00
kernel PM: hibernate: Allow hybrid sleep to work with s2idle 2022-11-04 00:00:31 +09:00
lib lib/Kconfig.debug: Add check for non-constant .{s,u}leb128 support to DWARF5 2022-10-21 12:39:29 +02:00
mm mm: prep_compound_tail() clear page->private 2022-11-04 00:00:23 +09:00
net tcp/udp: Fix memory leak in ipv6_renew_options(). 2022-11-04 00:00:35 +09:00
samples Tracing updates for 5.20 / 6.0 2022-08-05 09:41:12 -07:00
scripts kbuild: rpm-pkg: fix breakage when V=1 is used 2022-10-21 12:39:01 +02:00
security selinux: enable use of both GFP_KERNEL and GFP_ATOMIC in convert_context() 2022-10-29 10:08:29 +02:00
sound ALSA: aoa: Fix I2S device accounting 2022-11-04 00:00:33 +09:00
tools perf vendor events arm64: Fix incorrect Hisi hip08 L3 metrics 2022-11-04 00:00:32 +09:00
usr Not a lot of material this cycle. Many singleton patches against various 2022-05-27 11:22:03 -07:00
virt kvm: Add support for arch compat vm ioctls 2022-10-29 10:08:30 +02:00
.clang-format PCI/DOE: Add DOE mailbox support functions 2022-07-19 15:38:04 -07:00
.cocciconfig
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore kbuild: split the second line of *.mod into *.usyms 2022-05-08 03:16:59 +09:00
.mailmap Qualcomm ARM64 DTS fixes for 6.0 2022-09-23 16:44:37 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS drm for 5.20/6.0 2022-08-03 19:52:08 -07:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
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MAINTAINERS One MAINTAINERS update, two MM fixes, both cc:stable 2022-10-01 09:13:29 -07:00
Makefile Linux 6.0.6 2022-10-29 10:08:36 +02:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

README

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.