[moderation] [kernel?] KCSAN: data-race in kobject_put / kobject_uevent_env

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 18daea77cca6 Merge tag 'for-linus' of git://git.kernel.org..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=14332937180000
kernel config: https://syzkaller.appspot.com/x/.config?x=c3beef2aff822313
dashboard link: https://syzkaller.appspot.com/bug?extid=8c52032b484b510c8b5b
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
CC: [gre...@linuxfoundation.org linux-...@vger.kernel.org raf...@kernel.org]

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/bf6a505db597/disk-18daea77.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/eca1bb0a1073/vmlinux-18daea77.xz
kernel image: https://storage.googleapis.com/syzbot-assets/71723d8f8875/bzImage-18daea77.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+8c5203...@syzkaller.appspotmail.com

llcp: llcp_sock_recvmsg: Recv datagram failed state 3 -6 0
==================================================================
BUG: KCSAN: data-race in kobject_put / kobject_uevent_env

read-write to 0xffff888101070854 of 1 bytes by task 1621 on cpu 0:
kobject_uevent_env+0x4e/0x550 lib/kobject_uevent.c:476
kobject_uevent+0x1c/0x30 lib/kobject_uevent.c:641
device_del+0x729/0x7b0 drivers/base/core.c:3927
nfc_unregister_device+0x114/0x130 net/nfc/core.c:1183
nci_unregister_device+0x14c/0x160 net/nfc/nci/core.c:1312
virtual_ncidev_close+0x30/0x50 drivers/nfc/virtual_ncidev.c:168
__fput+0x2c1/0x660 fs/file_table.c:422
____fput+0x15/0x20 fs/file_table.c:450
task_work_run+0x13a/0x1a0 kernel/task_work.c:180
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0xbe/0x130 kernel/entry/common.c:218
do_syscall_64+0xda/0x1d0 arch/x86/entry/common.c:89
entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888101070854 of 1 bytes by task 1617 on cpu 1:
kobject_put+0x25/0x180 lib/kobject.c:733
put_device+0x1f/0x30 drivers/base/core.c:3828
nfc_put_device net/nfc/nfc.h:103 [inline]
nfc_llcp_local_put+0x87/0xb0 net/nfc/llcp_core.c:196
nfc_llcp_sock_free net/nfc/llcp_sock.c:1021 [inline]
llcp_sock_destruct+0x14d/0x1a0 net/nfc/llcp_sock.c:966
__sk_destruct+0x3d/0x440 net/core/sock.c:2175
sk_destruct net/core/sock.c:2223 [inline]
__sk_free+0x284/0x2d0 net/core/sock.c:2234
sk_free+0x39/0x70 net/core/sock.c:2245
sock_put include/net/sock.h:1950 [inline]
llcp_sock_release+0x38f/0x3d0 net/nfc/llcp_sock.c:646
__sock_release net/socket.c:659 [inline]
sock_close+0x68/0x150 net/socket.c:1421
__fput+0x2c1/0x660 fs/file_table.c:422
____fput+0x15/0x20 fs/file_table.c:450
task_work_run+0x13a/0x1a0 kernel/task_work.c:180
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0xbe/0x130 kernel/entry/common.c:218
do_syscall_64+0xda/0x1d0 arch/x86/entry/common.c:89
entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x07 -> 0x0d

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 1617 Comm: syz-executor.1 Tainted: G W 6.9.0-rc6-syzkaller-00046-g18daea77cca6 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
==================================================================


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