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Kuniyuki Iwashima 31b46d5e7c af_unix: Fix data-race around unix_tot_inflight.
[ Upstream commit ade32bd8a7 ]

unix_tot_inflight is changed under spin_lock(unix_gc_lock), but
unix_release_sock() reads it locklessly.

Let's use READ_ONCE() for unix_tot_inflight.

Note that the writer side was marked by commit 9d6d7f1cb6 ("af_unix:
annote lockless accesses to unix_tot_inflight & gc_in_progress")

BUG: KCSAN: data-race in unix_inflight / unix_release_sock

write (marked) to 0xffffffff871852b8 of 4 bytes by task 123 on cpu 1:
 unix_inflight+0x130/0x180 net/unix/scm.c:64
 unix_attach_fds+0x137/0x1b0 net/unix/scm.c:123
 unix_scm_to_skb net/unix/af_unix.c:1832 [inline]
 unix_dgram_sendmsg+0x46a/0x14f0 net/unix/af_unix.c:1955
 sock_sendmsg_nosec net/socket.c:724 [inline]
 sock_sendmsg+0x148/0x160 net/socket.c:747
 ____sys_sendmsg+0x4e4/0x610 net/socket.c:2493
 ___sys_sendmsg+0xc6/0x140 net/socket.c:2547
 __sys_sendmsg+0x94/0x140 net/socket.c:2576
 __do_sys_sendmsg net/socket.c:2585 [inline]
 __se_sys_sendmsg net/socket.c:2583 [inline]
 __x64_sys_sendmsg+0x45/0x50 net/socket.c:2583
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x72/0xdc

read to 0xffffffff871852b8 of 4 bytes by task 4891 on cpu 0:
 unix_release_sock+0x608/0x910 net/unix/af_unix.c:671
 unix_release+0x59/0x80 net/unix/af_unix.c:1058
 __sock_release+0x7d/0x170 net/socket.c:653
 sock_close+0x19/0x30 net/socket.c:1385
 __fput+0x179/0x5e0 fs/file_table.c:321
 ____fput+0x15/0x20 fs/file_table.c:349
 task_work_run+0x116/0x1a0 kernel/task_work.c:179
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:171 [inline]
 exit_to_user_mode_prepare+0x174/0x180 kernel/entry/common.c:204
 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline]
 syscall_exit_to_user_mode+0x1a/0x30 kernel/entry/common.c:297
 do_syscall_64+0x4b/0x90 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x72/0xdc

value changed: 0x00000000 -> 0x00000001

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 4891 Comm: systemd-coredum Not tainted 6.4.0-rc5-01219-gfa0e21fa4443 #5
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014

Fixes: 9305cfa444 ("[AF_UNIX]: Make unix_tot_inflight counter non-atomic")
Reported-by: syzkaller <syzkaller@googlegroups.com>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-09-23 10:47:02 +02:00
arch x86/virt: Drop unnecessary check on extended CPUID level in cpu_has_svm() 2023-09-23 10:47:01 +02:00
block block: bio-integrity: Copy flags when bio_integrity_payload is cloned 2023-03-11 16:26:35 +01:00
certs certs/blacklist_hashes.c: fix const confusion in certs blacklist 2022-06-25 11:46:44 +02:00
crypto X.509: if signature is unsupported skip validation 2023-09-23 10:47:01 +02:00
Documentation Documentation: security-bugs.rst: update preferences when dealing with the linux-distros group 2023-08-11 11:33:53 +02:00
drivers igb: disable virtualization features on 82580 2023-09-23 10:47:02 +02:00
firmware Fix built-in early-load Intel microcode alignment 2020-01-23 08:20:30 +01:00
fs NFSv4/pnfs: minor fix for cleanup path in nfs4_get_device_info 2023-09-23 10:47:01 +02:00
include net: handle ARPHRD_PPP in dev_is_mac_header_xmit() 2023-09-23 10:47:01 +02:00
init init, x86: Move mem_encrypt_init() into arch_cpu_finalize_init() 2023-08-08 19:48:24 +02:00
ipc ipc/sem: Fix dangling sem_array access in semtimedop race 2022-12-08 11:16:33 +01:00
kernel cgroup:namespace: Remove unused cgroup_namespaces_init() 2023-09-23 10:46:58 +02:00
lib lib/ubsan: remove returns-nonnull-attribute checks 2023-09-23 10:46:52 +02:00
mm treewide: Remove uninitialized_var() usage 2023-08-11 11:33:32 +02:00
net af_unix: Fix data-race around unix_tot_inflight. 2023-09-23 10:47:02 +02:00
samples samples/kretprobes: Fix return value if register_kretprobe() failed 2021-11-26 11:40:31 +01:00
scripts lib/ubsan: remove returns-nonnull-attribute checks 2023-09-23 10:46:52 +02:00
security smackfs: Prevent underflow in smk_set_cipso() 2023-09-23 10:46:56 +02:00
sound ALSA: pcm: Fix missing fixup call in compat hw_refine ioctl 2023-09-23 10:46:59 +02:00
tools radix tree test suite: fix incorrect allocation size for pthreads 2023-08-16 18:10:53 +02:00
usr initramfs: restore default compression behavior 2020-04-13 10:34:19 +02:00
virt KVM: arm64: vgic: Fix exit condition in scan_its_table() 2022-11-03 23:50:50 +09:00
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS Remove DECnet support from kernel 2023-06-21 15:38:58 +02:00
Makefile Linux 4.14.325 2023-09-02 09:21:33 +02:00
README

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

This file was moved to Documentation/admin-guide/README.rst

Please notice that there are several guides for kernel developers and users.
These guides can be rendered in a number of formats, like HTML and PDF.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

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.