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Wang Yufen 2486ab434b bpf, sockmap: Fix double uncharge the mem of sk_msg
If tcp_bpf_sendmsg is running during a tear down operation, psock may be
freed.

tcp_bpf_sendmsg()
 tcp_bpf_send_verdict()
  sk_msg_return()
  tcp_bpf_sendmsg_redir()
   unlikely(!psock))
     sk_msg_free()

The mem of msg has been uncharged in tcp_bpf_send_verdict() by
sk_msg_return(), and would be uncharged by sk_msg_free() again. When psock
is null, we can simply returning an error code, this would then trigger
the sk_msg_free_nocharge in the error path of __SK_REDIRECT and would have
the side effect of throwing an error up to user space. This would be a
slight change in behavior from user side but would look the same as an
error if the redirect on the socket threw an error.

This issue can cause the following info:
WARNING: CPU: 0 PID: 2136 at net/ipv4/af_inet.c:155 inet_sock_destruct+0x13c/0x260
Call Trace:
 <TASK>
 __sk_destruct+0x24/0x1f0
 sk_psock_destroy+0x19b/0x1c0
 process_one_work+0x1b3/0x3c0
 worker_thread+0x30/0x350
 ? process_one_work+0x3c0/0x3c0
 kthread+0xe6/0x110
 ? kthread_complete_and_exit+0x20/0x20
 ret_from_fork+0x22/0x30
 </TASK>

Fixes: 604326b41a ("bpf, sockmap: convert to generic sk_msg interface")
Signed-off-by: Wang Yufen <wangyufen@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20220304081145.2037182-5-wangyufen@huawei.com
2022-03-15 16:43:31 +01:00
Documentation Documentation/bpf: Add documentation for BPF_PROG_RUN 2022-03-09 14:19:22 -08:00
LICENSES LICENSES/LGPL-2.1: Add LGPL-2.1-or-later as valid identifiers 2021-12-16 14:33:10 +01:00
arch Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2022-03-04 19:28:17 -08:00
block block: clear iocb->private in blkdev_bio_end_io_async() 2022-02-22 06:59:49 -07:00
certs certs: Fix build error when CONFIG_MODULE_SIG_KEY is empty 2022-01-23 00:08:44 +09:00
crypto crypto: af_alg - get rid of alg_memory_allocated 2022-02-15 14:29:04 +00:00
drivers bnxt_en: add an nvm test for hw diagnose 2022-03-05 11:16:56 +00:00
fs Change since last update: 2022-03-02 12:08:36 -08:00
include bpf, sockmap: Fix memleak in sk_psock_queue_msg 2022-03-15 16:43:31 +01:00
init Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2022-02-09 18:40:56 -08:00
ipc ipc/sem: do not sleep with a spin lock held 2022-02-04 09:25:05 -08:00
kernel bpf-lsm: Make bpf_lsm_kernel_read_file() as sleepable 2022-03-10 18:57:55 -08:00
lib Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2022-03-04 19:28:17 -08:00
mm memblock: use kfree() to release kmalloced memblock regions 2022-02-26 12:00:44 -08:00
net bpf, sockmap: Fix double uncharge the mem of sk_msg 2022-03-15 16:43:31 +01:00
samples Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-02-17 11:44:20 -08:00
scripts scripts/pahole-flags.sh: Parse DWARF and generate BTF with multithreading. 2022-02-22 14:32:44 -08:00
security ima: Always return a file measurement in ima_file_hash() 2022-03-10 18:56:24 -08:00
sound spi: Make remove() return void 2022-02-28 10:43:07 -08:00
tools selftests/bpf: Fix a clang compilation error for send_signal.c 2022-03-11 22:18:13 +01:00
usr kbuild: remove include/linux/cyclades.h from header file check 2022-01-27 08:51:08 +01:00
virt KVM: Fix lockdep false negative during host resume 2022-02-17 09:52:50 -05:00
.clang-format genirq/msi: Make interrupt allocation less convoluted 2021-12-16 22:22:20 +01:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.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 .gitignore: ignore only top-level modules.builtin 2021-05-02 00:43:35 +09:00
.mailmap mailmap: update Roman Gushchin's email 2022-02-26 09:51:17 -08:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: replace a Microchip AT91 maintainer 2022-02-09 11:30:01 +01:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-03-03 11:55:12 -08:00
Makefile Linux 5.17-rc6 2022-02-27 14:36:33 -08:00
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.