linux-kernel - Re: [PATCH RFC v3 04/10] coredump: add coredump socket

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250506-pilze-wegstecken-1d792c7b79b7@brauner>
Date: Tue, 6 May 2025 10:24:12 +0200
From: Christian Brauner <brauner@...nel.org>
To: Kuniyuki Iwashima <kuniyu@...zon.com>
Cc: alexander@...alicyn.com, bluca@...ian.org, daan.j.demeyer@...il.com, 
	davem@...emloft.net, david@...dahead.eu, edumazet@...gle.com, horms@...nel.org, 
	jack@...e.cz, jannh@...gle.com, kuba@...nel.org, lennart@...ttering.net, 
	linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org, me@...dnzj.com, 
	netdev@...r.kernel.org, oleg@...hat.com, pabeni@...hat.com, viro@...iv.linux.org.uk, 
	zbyszek@...waw.pl
Subject: Re: [PATCH RFC v3 04/10] coredump: add coredump socket

On Mon, May 05, 2025 at 11:48:43AM -0700, Kuniyuki Iwashima wrote:
> From: Christian Brauner <brauner@...nel.org>
> Date: Mon, 05 May 2025 13:13:42 +0200
> > @@ -801,6 +846,40 @@ void do_coredump(const kernel_siginfo_t *siginfo)
> >  		}
> >  		break;
> >  	}
> > +	case COREDUMP_SOCK: {
> > +		struct file *file __free(fput) = NULL;
> > +#ifdef CONFIG_UNIX
> > +		struct socket *socket;
> > +
> > +		/*
> > +		 * It is possible that the userspace process which is
> > +		 * supposed to handle the coredump and is listening on
> > +		 * the AF_UNIX socket coredumps. Userspace should just
> > +		 * mark itself non dumpable.
> > +		 */
> > +
> > +		retval = sock_create_kern(&init_net, AF_UNIX, SOCK_STREAM, 0, &socket);
> > +		if (retval < 0)
> > +			goto close_fail;
> > +
> > +		file = sock_alloc_file(socket, 0, NULL);
> > +		if (IS_ERR(file)) {
> > +			sock_release(socket);
> > +			retval = PTR_ERR(file);
> > +			goto close_fail;
> > +		}
> > +
> > +		retval = kernel_connect(socket,
> > +					(struct sockaddr *)(&coredump_unix_socket),
> > +					COREDUMP_UNIX_SOCKET_ADDR_SIZE, 0);
> 
> This blocks forever if the listener's accept() queue is full.
> 
> I think we don't want that and should pass O_NONBLOCK.
> 
> To keep the queue clean is userspace responsibility, and we don't
> need to care about a weird user.

That seems fine to me. I've changed that.