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Eric Dumazet 5e5265522a tcp: annotate data-races around tcp_rsk(req)->txhash
TCP request sockets are lockless, some of their fields
can change while being read by another cpu as syzbot noticed.

This is usually harmless, but we should annotate the known
races.

This patch takes care of tcp_rsk(req)->txhash,
a separate one is needed for tcp_rsk(req)->ts_recent.

BUG: KCSAN: data-race in tcp_make_synack / tcp_rtx_synack

write to 0xffff8881362304bc of 4 bytes by task 32083 on cpu 1:
tcp_rtx_synack+0x9d/0x2a0 net/ipv4/tcp_output.c:4213
inet_rtx_syn_ack+0x38/0x80 net/ipv4/inet_connection_sock.c:880
tcp_check_req+0x379/0xc70 net/ipv4/tcp_minisocks.c:665
tcp_v6_rcv+0x125b/0x1b20 net/ipv6/tcp_ipv6.c:1673
ip6_protocol_deliver_rcu+0x92f/0xf30 net/ipv6/ip6_input.c:437
ip6_input_finish net/ipv6/ip6_input.c:482 [inline]
NF_HOOK include/linux/netfilter.h:303 [inline]
ip6_input+0xbd/0x1b0 net/ipv6/ip6_input.c:491
dst_input include/net/dst.h:468 [inline]
ip6_rcv_finish+0x1e2/0x2e0 net/ipv6/ip6_input.c:79
NF_HOOK include/linux/netfilter.h:303 [inline]
ipv6_rcv+0x74/0x150 net/ipv6/ip6_input.c:309
__netif_receive_skb_one_core net/core/dev.c:5452 [inline]
__netif_receive_skb+0x90/0x1b0 net/core/dev.c:5566
netif_receive_skb_internal net/core/dev.c:5652 [inline]
netif_receive_skb+0x4a/0x310 net/core/dev.c:5711
tun_rx_batched+0x3bf/0x400
tun_get_user+0x1d24/0x22b0 drivers/net/tun.c:1997
tun_chr_write_iter+0x18e/0x240 drivers/net/tun.c:2043
call_write_iter include/linux/fs.h:1871 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x4ab/0x7d0 fs/read_write.c:584
ksys_write+0xeb/0x1a0 fs/read_write.c:637
__do_sys_write fs/read_write.c:649 [inline]
__se_sys_write fs/read_write.c:646 [inline]
__x64_sys_write+0x42/0x50 fs/read_write.c:646
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

read to 0xffff8881362304bc of 4 bytes by task 32078 on cpu 0:
tcp_make_synack+0x367/0xb40 net/ipv4/tcp_output.c:3663
tcp_v6_send_synack+0x72/0x420 net/ipv6/tcp_ipv6.c:544
tcp_conn_request+0x11a8/0x1560 net/ipv4/tcp_input.c:7059
tcp_v6_conn_request+0x13f/0x180 net/ipv6/tcp_ipv6.c:1175
tcp_rcv_state_process+0x156/0x1de0 net/ipv4/tcp_input.c:6494
tcp_v6_do_rcv+0x98a/0xb70 net/ipv6/tcp_ipv6.c:1509
tcp_v6_rcv+0x17b8/0x1b20 net/ipv6/tcp_ipv6.c:1735
ip6_protocol_deliver_rcu+0x92f/0xf30 net/ipv6/ip6_input.c:437
ip6_input_finish net/ipv6/ip6_input.c:482 [inline]
NF_HOOK include/linux/netfilter.h:303 [inline]
ip6_input+0xbd/0x1b0 net/ipv6/ip6_input.c:491
dst_input include/net/dst.h:468 [inline]
ip6_rcv_finish+0x1e2/0x2e0 net/ipv6/ip6_input.c:79
NF_HOOK include/linux/netfilter.h:303 [inline]
ipv6_rcv+0x74/0x150 net/ipv6/ip6_input.c:309
__netif_receive_skb_one_core net/core/dev.c:5452 [inline]
__netif_receive_skb+0x90/0x1b0 net/core/dev.c:5566
netif_receive_skb_internal net/core/dev.c:5652 [inline]
netif_receive_skb+0x4a/0x310 net/core/dev.c:5711
tun_rx_batched+0x3bf/0x400
tun_get_user+0x1d24/0x22b0 drivers/net/tun.c:1997
tun_chr_write_iter+0x18e/0x240 drivers/net/tun.c:2043
call_write_iter include/linux/fs.h:1871 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x4ab/0x7d0 fs/read_write.c:584
ksys_write+0xeb/0x1a0 fs/read_write.c:637
__do_sys_write fs/read_write.c:649 [inline]
__se_sys_write fs/read_write.c:646 [inline]
__x64_sys_write+0x42/0x50 fs/read_write.c:646
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x91d25731 -> 0xe79325cd

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 32078 Comm: syz-executor.4 Not tainted 6.5.0-rc1-syzkaller-00033-geb26cbb1a754 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/03/2023

Fixes: 58d607d3e5 ("tcp: provide skb->hash to synack packets")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20230717144445.653164-2-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-07-18 19:45:27 -07:00
arch Networking fixes for 6.5-rc2, including fixes from netfilter, 2023-07-13 14:21:22 -07:00
block block-6.5-2023-07-03 2023-07-03 18:48:38 -07:00
certs KEYS: Add missing function documentation 2023-04-24 16:15:52 +03:00
crypto crypto: algif_hash - Fix race between MORE and non-MORE sends 2023-07-08 22:48:42 +10:00
Documentation Networking fixes for 6.5-rc2, including fixes from netfilter, 2023-07-13 14:21:22 -07:00
drivers octeontx2-pf: mcs: Generate hash key using ecb(aes) 2023-07-18 19:21:56 -07:00
fs Minor cleanups for 6.5: 2023-07-09 09:50:42 -07:00
include rsi: remove kernel-doc comment marker 2023-07-14 20:39:30 -07:00
init Kbuild updates for v6.5 2023-07-01 09:24:31 -07:00
io_uring io_uring-6.5-2023-07-03 2023-07-03 18:43:10 -07:00
ipc Merge branch 'work.namespace' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2023-02-24 19:20:07 -08:00
kernel Networking fixes for 6.5-rc2, including fixes from netfilter, 2023-07-13 14:21:22 -07:00
lib 16 hotfixes. Six are cc:stable and the remainder address post-6.4 issues. 2023-07-08 14:30:25 -07:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm mm: lock newly mapped VMA with corrected ordering 2023-07-08 16:44:11 -07:00
net tcp: annotate data-races around tcp_rsk(req)->txhash 2023-07-18 19:45:27 -07:00
rust rust: error: impl Debug for Error with errname() integration 2023-06-13 01:24:42 +02:00
samples arm64: ftrace: Add direct call trampoline samples support 2023-07-10 17:51:54 -04:00
scripts A half-dozen late arriving docs patches. They are mostly fixes, but we 2023-07-06 22:15:38 -07:00
security + Bug Fixes 2023-07-07 09:55:31 -07:00
sound sound fixes for 6.5-rc1 2023-07-07 15:40:17 -07:00
tools selftests: tc: add ConnTrack procfs kconfig 2023-07-18 16:52:12 -07:00
usr initramfs: Encode dependency on KBUILD_BUILD_TIMESTAMP 2023-06-06 17:54:49 +09:00
virt ARM64: 2023-07-03 15:32:22 -07:00
.clang-format iommu: Add for_each_group_device() 2023-05-23 08:15:51 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore Revert ".gitignore: ignore *.cover and *.mbx" 2023-07-04 15:05:12 -07:00
.mailmap mailmap: Add entry for old intel email 2023-07-18 18:27:59 -07:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS - Address -Wmissing-prototype warnings 2023-06-26 16:43:54 -07:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS Networking fixes for 6.5-rc2, including fixes from netfilter, 2023-07-13 14:21:22 -07:00
Makefile Linux 6.5-rc1 2023-07-09 13:53:13 -07:00
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.