[moderation] [ext4?] [block?] KCSAN: data-race in data_push_tail / vsnprintf (6)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 3ca112b71f35 Merge tag 'probes-fixes-v6.7-rc1' of git://gi..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=13aaa0db680000
kernel config: https://syzkaller.appspot.com/x/.config?x=1c4caf9f31b81308
dashboard link: https://syzkaller.appspot.com/bug?extid=96a41bfe9f245b3c8350
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
CC: [adilger...@dilger.ca da...@davemloft.net edum...@google.com ku...@kernel.org linux...@vger.kernel.org linux...@vger.kernel.org linux-...@vger.kernel.org linux-...@vger.kernel.org net...@vger.kernel.org pab...@redhat.com ty...@mit.edu]

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/06b08cfc6edb/disk-3ca112b7.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/4015d21a3b25/vmlinux-3ca112b7.xz
kernel image: https://storage.googleapis.com/syzbot-assets/27b26ecfc1c5/bzImage-3ca112b7.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+96a41b...@syzkaller.appspotmail.com

SELinux: unrecognized netlink message: protocol=0 nlmsg_type=1060 sclass=netlink_route_socket pid=8641 comm=syz-executor.1
==================================================================
BUG: KCSAN: data-race in data_push_tail / vsnprintf

write to 0xffffffff86ed69cb of 1 bytes by task 8640 on cpu 1:
vsnprintf+0xdd0/0xe20
vscnprintf+0x42/0x80 lib/vsprintf.c:2925
printk_sprint+0x30/0x2d0 kernel/printk/printk.c:2124
vprintk_store+0x56f/0x800 kernel/printk/printk.c:2238
vprintk_emit+0xd0/0x5d0 kernel/printk/printk.c:2284
vprintk_default+0x26/0x30 kernel/printk/printk.c:2318
vprintk+0x71/0x80 kernel/printk/printk_safe.c:45
_printk+0x7a/0xa0 kernel/printk/printk.c:2328
__nla_validate_parse+0x1768/0x1d00 lib/nlattr.c:643
__nla_parse+0x40/0x50 lib/nlattr.c:728
nla_parse_nested_deprecated include/net/netlink.h:1288 [inline]
__rtnl_newlink net/core/rtnetlink.c:3619 [inline]
rtnl_newlink+0x3fa/0x1670 net/core/rtnetlink.c:3754
rtnetlink_rcv_msg+0x807/0x8c0 net/core/rtnetlink.c:6558
netlink_rcv_skb+0x126/0x220 net/netlink/af_netlink.c:2545
rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:6576
netlink_unicast_kernel net/netlink/af_netlink.c:1342 [inline]
netlink_unicast+0x589/0x650 net/netlink/af_netlink.c:1368
netlink_sendmsg+0x66e/0x770 net/netlink/af_netlink.c:1910
sock_sendmsg_nosec net/socket.c:730 [inline]
__sock_sendmsg net/socket.c:745 [inline]
____sys_sendmsg+0x37c/0x4d0 net/socket.c:2584
___sys_sendmsg net/socket.c:2638 [inline]
__sys_sendmsg+0x1e9/0x270 net/socket.c:2667
__do_sys_sendmsg net/socket.c:2676 [inline]
__se_sys_sendmsg net/socket.c:2674 [inline]
__x64_sys_sendmsg+0x46/0x50 net/socket.c:2674
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x63/0x6b

read to 0xffffffff86ed69c8 of 8 bytes by task 8641 on cpu 0:
data_make_reusable kernel/printk/printk_ringbuffer.c:590 [inline]
data_push_tail+0x102/0x430 kernel/printk/printk_ringbuffer.c:675
data_alloc+0xbe/0x2c0 kernel/printk/printk_ringbuffer.c:1046
prb_reserve+0x893/0xbc0 kernel/printk/printk_ringbuffer.c:1555
vprintk_store+0x53e/0x800 kernel/printk/printk.c:2228
vprintk_emit+0xd0/0x5d0 kernel/printk/printk.c:2284
vprintk_default+0x26/0x30 kernel/printk/printk.c:2318
vprintk+0x71/0x80 kernel/printk/printk_safe.c:45
_printk+0x7a/0xa0 kernel/printk/printk.c:2328
selinux_netlink_send+0x393/0x400 security/selinux/hooks.c:5906
security_netlink_send+0x3e/0x70 security/security.c:3867
netlink_sendmsg+0x563/0x770 net/netlink/af_netlink.c:1900
sock_sendmsg_nosec net/socket.c:730 [inline]
__sock_sendmsg net/socket.c:745 [inline]
____sys_sendmsg+0x37c/0x4d0 net/socket.c:2584
___sys_sendmsg net/socket.c:2638 [inline]
__sys_sendmsg+0x1e9/0x270 net/socket.c:2667
__do_sys_sendmsg net/socket.c:2676 [inline]
__se_sys_sendmsg net/socket.c:2674 [inline]
__x64_sys_sendmsg+0x46/0x50 net/socket.c:2674
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x63/0x6b

value changed: 0x000000010000aba6 -> 0x00000001000a2e27

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 8641 Comm: syz-executor.1 Not tainted 6.6.0-syzkaller-16159-g3ca112b71f35 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
==================================================================


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.