linux-kernel - [syzbot] [selinux?] KCSAN: data-race in selinux_socket_post_create / selinux_socket_sock_rcv

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Message-ID: <67cb894d.050a0220.d8275.0232.GAE@google.com>
Date: Fri, 07 Mar 2025 16:03:25 -0800
From: syzbot <syzbot+00c633585760c05507c3@...kaller.appspotmail.com>
To: linux-kernel@...r.kernel.org, omosnace@...hat.com, paul@...l-moore.com, 
	selinux@...r.kernel.org, stephen.smalley.work@...il.com, 
	syzkaller-bugs@...glegroups.com
Subject: [syzbot] [selinux?] KCSAN: data-race in selinux_socket_post_create / selinux_socket_sock_rcv_skb

Hello,

syzbot found the following issue on:

HEAD commit:    0f52fd4f67c6 Merge tag 'bcachefs-2025-03-06' of git://evil..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=11a5ca64580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=523b0e2f15224775
dashboard link: https://syzkaller.appspot.com/bug?extid=00c633585760c05507c3
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/eb0d7b540c67/disk-0f52fd4f.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/51c261332ad9/vmlinux-0f52fd4f.xz
kernel image: https://storage.googleapis.com/syzbot-assets/38914a4790c8/bzImage-0f52fd4f.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+00c633585760c05507c3@...kaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in selinux_socket_post_create / selinux_socket_sock_rcv_skb

write to 0xffff88811b989e30 of 4 bytes by task 3803 on cpu 0:
 selinux_socket_post_create+0x1b5/0x2a0 security/selinux/hooks.c:4681
 security_socket_post_create+0x5b/0xa0 security/security.c:4577
 __sock_create+0x35b/0x5a0 net/socket.c:1571
 sock_create net/socket.c:1606 [inline]
 __sys_socket_create net/socket.c:1643 [inline]
 __sys_socket+0xae/0x240 net/socket.c:1690
 __do_sys_socket net/socket.c:1704 [inline]
 __se_sys_socket net/socket.c:1702 [inline]
 __x64_sys_socket+0x3f/0x50 net/socket.c:1702
 x64_sys_call+0x2cf2/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:42
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff88811b989e30 of 4 bytes by task 3805 on cpu 1:
 selinux_socket_sock_rcv_skb+0x72/0x6a0 security/selinux/hooks.c:5129
 security_sock_rcv_skb+0x3d/0x80 security/security.c:4781
 sk_filter_trim_cap+0xca/0x3c0 net/core/filter.c:151
 sk_filter include/linux/filter.h:1062 [inline]
 sock_queue_rcv_skb_reason+0x28/0xc0 net/core/sock.c:527
 sock_queue_rcv_skb include/net/sock.h:2403 [inline]
 packet_rcv_spkt+0x2f7/0x3b0 net/packet/af_packet.c:1967
 deliver_skb net/core/dev.c:2449 [inline]
 __netif_receive_skb_core+0x48f/0x2350 net/core/dev.c:5737
 __netif_receive_skb_list_core+0x115/0x520 net/core/dev.c:5968
 __netif_receive_skb_list net/core/dev.c:6035 [inline]
 netif_receive_skb_list_internal+0x4e4/0x660 net/core/dev.c:6126
 netif_receive_skb_list+0x31/0x230 net/core/dev.c:6178
 xdp_recv_frames net/bpf/test_run.c:280 [inline]
 xdp_test_run_batch net/bpf/test_run.c:361 [inline]
 bpf_test_run_xdp_live+0xe10/0x1040 net/bpf/test_run.c:390
 bpf_prog_test_run_xdp+0x51d/0x8b0 net/bpf/test_run.c:1316
 bpf_prog_test_run+0x20f/0x3a0 kernel/bpf/syscall.c:4407
 __sys_bpf+0x400/0x7a0 kernel/bpf/syscall.c:5813
 __do_sys_bpf kernel/bpf/syscall.c:5902 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5900 [inline]
 __x64_sys_bpf+0x43/0x50 kernel/bpf/syscall.c:5900
 x64_sys_call+0x2914/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:322
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x00000003 -> 0x00000087

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 3805 Comm: syz.4.118 Not tainted 6.14.0-rc5-syzkaller-00109-g0f52fd4f67c6 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
==================================================================
syz.4.118 (3805) used greatest stack depth: 10328 bytes left


---
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