Message-ID: <20250612211610.4129612-1-kuni1840@gmail.com>
Date: Thu, 12 Jun 2025 14:16:04 -0700
From: Kuniyuki Iwashima <kuni1840@...il.com>
To: syzbot+a4cc4ac22daa4a71b87c@...kaller.appspotmail.com
Cc: Dai.Ngo@...cle.com,
	anna@...nel.org,
	chuck.lever@...cle.com,
	davem@...emloft.net,
	edumazet@...gle.com,
	horms@...nel.org,
	jlayton@...nel.org,
	kuba@...nel.org,
	linux-kernel@...r.kernel.org,
	linux-nfs@...r.kernel.org,
	neil@...wn.name,
	netdev@...r.kernel.org,
	okorniev@...hat.com,
	pabeni@...hat.com,
	syzkaller-bugs@...glegroups.com,
	tom@...pey.com,
	trondmy@...nel.org
Subject: Re: [syzbot] [net?] [nfs?] WARNING in remove_proc_entry (8)

From: syzbot <syzbot+a4cc4ac22daa4a71b87c@...kaller.appspotmail.com>
Date: Thu, 12 Jun 2025 14:08:31 -0700
> Hello,
> 
> syzbot found the following issue on:
> 
> HEAD commit:    2c4a1f3fe03e Merge tag 'bpf-fixes' of git://git.kernel.org..
> git tree:       upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=1432610c580000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=c4c8362784bb7796
> dashboard link: https://syzkaller.appspot.com/bug?extid=a4cc4ac22daa4a71b87c
> compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1126ed70580000
> 
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/cd1ec81a3ab8/disk-2c4a1f3f.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/992d9b6a25bf/vmlinux-2c4a1f3f.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/85a9bf583faa/bzImage-2c4a1f3f.xz
> 
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+a4cc4ac22daa4a71b87c@...kaller.appspotmail.com
> 
> WARNING: CPU: 0 PID: 6182 at fs/proc/generic.c:727 remove_proc_entry+0x45e/0x530 fs/proc/generic.c:727
> Modules linked in:
> CPU: 0 UID: 0 PID: 6182 Comm: syz.1.75 Not tainted 6.16.0-rc1-syzkaller-00010-g2c4a1f3fe03e #0 PREEMPT(full) 
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
> RIP: 0010:remove_proc_entry+0x45e/0x530 fs/proc/generic.c:727
> Code: 3c 02 00 0f 85 85 00 00 00 48 8b 93 d8 00 00 00 4d 89 f0 4c 89 e9 48 c7 c6 40 ba a2 8b 48 c7 c7 60 b9 a2 8b e8 33 81 1d ff 90 <0f> 0b 90 90 e9 5f fe ff ff e8 04 69 5e ff 90 48 b8 00 00 00 00 00
> RSP: 0018:ffffc90003e5fb08 EFLAGS: 00010282
> RAX: 0000000000000000 RBX: ffff88804e6568c0 RCX: ffffffff817a92c8
> RDX: ffff88803046da00 RSI: ffffffff817a92d5 RDI: 0000000000000001
> RBP: ffff8880353bde80 R08: 0000000000000001 R09: 0000000000000000
> R10: 0000000000000001 R11: 0000000000000001 R12: ffff8880353bddc0
> R13: ffff8880353bdea4 R14: ffff88802556cae4 R15: dffffc0000000000
> FS:  0000555562486500(0000) GS:ffff888124962000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 000000c0024fb070 CR3: 000000006b39a000 CR4: 00000000003526f0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> Call Trace:
>  <TASK>
>  sunrpc_exit_net+0x46/0x90 net/sunrpc/sunrpc_syms.c:76
>  ops_exit_list net/core/net_namespace.c:200 [inline]
>  ops_undo_list+0x2eb/0xab0 net/core/net_namespace.c:253
>  setup_net+0x2e1/0x510 net/core/net_namespace.c:457
>  copy_net_ns+0x2a6/0x5f0 net/core/net_namespace.c:574
>  create_new_namespaces+0x3ea/0xa90 kernel/nsproxy.c:110
>  unshare_nsproxy_namespaces+0xc0/0x1f0 kernel/nsproxy.c:218
>  ksys_unshare+0x45b/0xa40 kernel/fork.c:3121
>  __do_sys_unshare kernel/fork.c:3192 [inline]
>  __se_sys_unshare kernel/fork.c:3190 [inline]
>  __x64_sys_unshare+0x31/0x40 kernel/fork.c:3190
>  do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
>  do_syscall_64+0xcd/0x490 arch/x86/entry/syscall_64.c:94
>  entry_SYSCALL_64_after_hwframe+0x77/0x7f
> RIP: 0033:0x7f239858e929
> Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
> RSP: 002b:00007ffd08ac9b18 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
> RAX: ffffffffffffffda RBX: 00007f23987b5fa0 RCX: 00007f239858e929
> RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000080
> RBP: 00007f2398610b39 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
> R13: 00007f23987b5fa0 R14: 00007f23987b5fa0 R15: 0000000000000001
>  </TASK>
> 
> 
> ---
> This report is generated by a bot. It may contain errors.
> See https://goo.gl/tpsmEJ for more information about syzbot.
> syzbot engineers can be reached at syzkaller@...glegroups.com.
> 
> syzbot will keep track of this issue. See:
> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
> 
> If the report is already addressed, let syzbot know by replying with:
> #syz fix: exact-commit-title
> 
> If you want syzbot to run the reproducer, reply with:
> #syz test: git://repo/address.git branch-or-commit-hash
> If you attach or paste a git patch, syzbot will apply it before testing.

#syz test

diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index 8ab7868807a7..19277e050c09 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -2589,15 +2589,26 @@ EXPORT_SYMBOL_GPL(nfs_net_id);
 static int nfs_net_init(struct net *net)
 {
 	struct nfs_net *nn = net_generic(net, nfs_net_id);
+	int err;
 
 	nfs_clients_init(net);
 
 	if (!rpc_proc_register(net, &nn->rpcstats)) {
-		nfs_clients_exit(net);
-		return -ENOMEM;
+		goto err_proc_rpc;
+		err = -ENOMEM;
 	}
 
-	return nfs_fs_proc_net_init(net);
+	err = nfs_fs_proc_net_init(net);
+	if (err)
+		goto err_proc_nfs;
+
+	return 0;
+
+err_proc_nfs:
+	rpc_proc_unregister(net, "nfs");
+err_proc_rpc:
+	nfs_clients_exit(net);
+	return err;
 }
 
 static void nfs_net_exit(struct net *net)

Powered by blists - more mailing lists