[syzbot] [fs?] WARNING: proc registration bug in bcm_connect

[syzbot] [fs?] WARNING: proc registration bug in bcm_connect

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    d46efae31672 Merge branch 'for-next/core' into for-kernelci
git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci
console output: https://syzkaller.appspot.com/x/log.txt?x=123d805ce80000
kernel config:  https://syzkaller.appspot.com/x/.config?x=f62dd67b72f86455
dashboard link: https://syzkaller.appspot.com/bug?extid=df49d48077305d17519a
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: arm64
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=112e94fae80000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=11b971dae80000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/f1c7fab7b512/disk-d46efae3.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/44ed3d86d2c1/vmlinux-d46efae3.xz
kernel image: https://storage.googleapis.com/syzbot-assets/2e0b5f52455a/Image-d46efae3.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+df49d48077305d17519a@syzkaller.appspotmail.com

__nla_validate_parse: 1 callbacks suppressed
netlink: 4 bytes leftover after parsing attributes in process `syz-executor167'.
------------[ cut here ]------------
proc_dir_entry 'can-bcm/3005' already registered
WARNING: CPU: 0 PID: 6120 at fs/proc/generic.c:376 proc_register+0x2e8/0x464 fs/proc/generic.c:377
Modules linked in:
CPU: 0 PID: 6120 Comm: syz-executor167 Not tainted 6.7.0-rc4-syzkaller-gd46efae31672 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023
pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : proc_register+0x2e8/0x464 fs/proc/generic.c:377
lr : proc_register+0x2e0/0x464 fs/proc/generic.c:375
sp : ffff800096fa7a40
x29: ffff800096fa7a60 x28: dfff800000000000 x27: 0000000000000000
x26: 0000000000000004 x25: ffff0000d3567ab8 x24: ffff0000c92524a4
x23: ffff0000c9252498 x22: 1fffe0001924a48a x21: ffff0000c9252454
x20: ffff0000d3567ae4 x19: ffff0000c92523c0 x18: ffff800096fa6f20
x17: 0000000000000000 x16: ffff80008a82b29c x15: 0000000000000001
x14: 1fffe0003682623a x13: 0000000000000000 x12: 0000000000000000
x11: 0000000000000003 x10: 0000000000ff0100 x9 : 4358bb8e0c091100
x8 : 4358bb8e0c091100 x7 : 0000000000000001 x6 : 0000000000000001
x5 : ffff800096fa7338 x4 : ffff80008e5d1ea0 x3 : ffff8000805af654
x2 : 0000000000000001 x1 : 0000000100000001 x0 : ffff80008e80d580
Call trace:
 proc_register+0x2e8/0x464 fs/proc/generic.c:377
 proc_create_net_single+0x140/0x198 fs/proc/proc_net.c:219
 bcm_connect+0x224/0x43c net/can/bcm.c:1631
 __sys_connect_file net/socket.c:2046 [inline]
 __sys_connect+0x268/0x290 net/socket.c:2063
 __do_sys_connect net/socket.c:2073 [inline]
 __se_sys_connect net/socket.c:2070 [inline]
 __arm64_sys_connect+0x7c/0x94 net/socket.c:2070
 __invoke_syscall arch/arm64/kernel/syscall.c:37 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:51
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:136
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:155
 el0_svc+0x54/0x158 arch/arm64/kernel/entry-common.c:678
 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:696
 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:595
irq event stamp: 2368
hardirqs last  enabled at (2367): [<ffff80008035a900>] __up_console_sem kernel/printk/printk.c:341 [inline]
hardirqs last  enabled at (2367): [<ffff80008035a900>] __console_unlock kernel/printk/printk.c:2706 [inline]
hardirqs last  enabled at (2367): [<ffff80008035a900>] console_unlock+0x17c/0x3d4 kernel/printk/printk.c:3038
hardirqs last disabled at (2368): [<ffff80008a826dc0>] el1_dbg+0x24/0x80 arch/arm64/kernel/entry-common.c:436
softirqs last  enabled at (2338): [<ffff8000889a2938>] local_bh_enable+0x10/0x34 include/linux/bottom_half.h:32
softirqs last disabled at (2336): [<ffff8000889a2904>] local_bh_disable+0x10/0x34 include/linux/bottom_half.h:19
---[ end trace 0000000000000000 ]---


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