From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0D2022C3242 for ; Thu, 5 Jun 2025 09:53:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749117215; cv=none; b=f6HcF3vH2Nz9tPCJgLf8hBIwIbtgHrBxnaxKCe8ZcnKuTZg3gSLrt47oMrJSMdID0FjQHty92Rwy5A4QG7X90irhm4nHXggtGfv8Dxx9WnUcncWV4RDEeHPtPPGzc3ud9eC0kNGpFFlgtMj5Dyx4vqNcgBddkKka/9u9dvG22N4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749117215; c=relaxed/simple; bh=mW8rsPuXw3nVhLHFk3N0mUcTcpixe+P0UMYtzIRiv5c=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=dCSELRwQtvtObDKPzmZN2g/RK/1deY3NCL6Hzjhj+l9oybV7X50kVl0Zbmtfpu5iLXQfkGbsJ7IgohpwYAc9EOWWpcpwVYkcW9egWmCj71yN2TrpVFPlDe3fJR3BevBvDgpndWR2JUGppHIbUg979hw9ei2imoBYJQS0BhwoDKg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=FDD6dUVA; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="FDD6dUVA" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B9ACEC4CEE7; Thu, 5 Jun 2025 09:53:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1749117213; bh=mW8rsPuXw3nVhLHFk3N0mUcTcpixe+P0UMYtzIRiv5c=; h=From:To:Cc:Subject:Date:From; b=FDD6dUVAjsA+rXIUtKNMLChpCEvzF6B5J8yyCmu3K9wXx1rSHHZJ+4vIDb5wtdYuV YbGGzMX1hKqO6eqJZw6elyfdDMzlMD9ZXWZOOrON7H5DQZJCsiCcGcFxPUFYMvPnAj AUNl87m2BynhAMQubkZb6ClwKSK6BMRc4YxBjM56azMPNsymjXALY6kpNGUukstvYT s0xWs2Fjitq+L+UjB7wBQl0nmZYNyQqfQ69fn1JbFJy0XMdDnkC5HO9WjM9qabJ1hM TkfZ39PzrBC+p0D3Nqd0RuFTkO529Bl/c4RzQQzaBUTEVTElfMmwyiiZd5pWGHrP4/ kxn1fkY7EeJcw== From: Christian Brauner To: linux-fsdevel@vger.kernel.org Cc: Christian Brauner , Jann Horn , Josef Bacik , Jeff Layton , Alexander Viro , Daan De Meyer , Jan Kara , Lennart Poettering , Mike Yuan , =?UTF-8?q?Zbigniew=20J=C4=99drzejewski-Szmek?= , Alexander Mikhalitsyn Subject: [PATCH] coredump: cleanup coredump socket functions Date: Thu, 5 Jun 2025 11:53:15 +0200 Message-ID: <20250605-schlamm-touren-720ba2b60a85@brauner> X-Mailer: git-send-email 2.47.2 Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=6326; i=brauner@kernel.org; h=from:subject:message-id; bh=mW8rsPuXw3nVhLHFk3N0mUcTcpixe+P0UMYtzIRiv5c=; b=owGbwMvMwCU28Zj0gdSKO4sYT6slMWQ4Zoowcm1++1c7V2bendOWireWXguf3j7zU3ardUzhZ quOm+e3dZSyMIhxMciKKbI4tJuEyy3nqdhslKkBM4eVCWQIAxenAExE34qRYddTjhdZZzZ8rH07 zaoiS6Ff6eqpq9MLxK2FnOsW/v11WJnhr6jNnF+v1ZhXsxo9lo4IMVhX6Tdr++rZ+RP/mm75dv7 MdSYA X-Developer-Key: i=brauner@kernel.org; a=openpgp; fpr=4880B8C9BD0E5106FC070F4F7B3C391EFEA93624 Content-Transfer-Encoding: 8bit We currently use multiple CONFIG_UNIX guards. This looks messy and makes the code harder to follow and maintain. Use a helper function coredump_sock_connect() that handles the connect portion. This allows us to remove the CONFIG_UNIX guard in the main do_coredump() function. Signed-off-by: Christian Brauner --- fs/coredump.c | 154 +++++++++++++++++++++++++++----------------------- 1 file changed, 82 insertions(+), 72 deletions(-) diff --git a/fs/coredump.c b/fs/coredump.c index 26443018266e..11859d53afee 100644 --- a/fs/coredump.c +++ b/fs/coredump.c @@ -646,6 +646,77 @@ static int umh_coredump_setup(struct subprocess_info *info, struct cred *new) } #ifdef CONFIG_UNIX +static bool coredump_sock_connect(struct core_name *cn, struct coredump_params *cprm) +{ + struct file *file __free(fput) = NULL; + struct sockaddr_un addr = { + .sun_family = AF_UNIX, + }; + ssize_t addr_len; + int retval; + struct socket *socket; + + addr_len = strscpy(addr.sun_path, cn->corename); + if (addr_len < 0) + return false; + addr_len += offsetof(struct sockaddr_un, sun_path) + 1; + + /* + * 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) + return false; + + file = sock_alloc_file(socket, 0, NULL); + if (IS_ERR(file)) + return false; + + /* + * Set the thread-group leader pid which is used for the peer + * credentials during connect() below. Then immediately register + * it in pidfs... + */ + cprm->pid = task_tgid(current); + retval = pidfs_register_pid(cprm->pid); + if (retval) + return false; + + /* + * ... and set the coredump information so userspace has it + * available after connect()... + */ + pidfs_coredump(cprm); + + retval = kernel_connect(socket, (struct sockaddr *)(&addr), addr_len, + O_NONBLOCK | SOCK_COREDUMP); + /* + * ... Make sure to only put our reference after connect() took + * its own reference keeping the pidfs entry alive ... + */ + pidfs_put_pid(cprm->pid); + + if (retval) { + if (retval == -EAGAIN) + coredump_report_failure("Coredump socket %s receive queue full", addr.sun_path); + else + coredump_report_failure("Coredump socket connection %s failed %d", addr.sun_path, retval); + return false; + } + + /* ... and validate that @sk_peer_pid matches @cprm.pid. */ + if (WARN_ON_ONCE(unix_peer(socket->sk)->sk_peer_pid != cprm->pid)) + return false; + + cprm->limit = RLIM_INFINITY; + cprm->file = no_free_ptr(file); + + return true; +} + static inline bool coredump_sock_recv(struct file *file, struct coredump_ack *ack, size_t size, int flags) { struct msghdr msg = {}; @@ -709,7 +780,7 @@ static inline void coredump_sock_shutdown(struct file *file) kernel_sock_shutdown(socket, SHUT_WR); } -static bool coredump_request(struct core_name *cn, struct coredump_params *cprm) +static bool coredump_sock_request(struct core_name *cn, struct coredump_params *cprm) { struct coredump_req req = { .size = sizeof(struct coredump_req), @@ -759,6 +830,14 @@ static bool coredump_request(struct core_name *cn, struct coredump_params *cprm) return true; } #else +static bool coredump_sock_connect(struct core_name *cn, + struct coredump_params *cprm) +{ + coredump_report_failure("Core dump socket support %s disabled", cn->corename); + return false; +} +static bool coredump_sock_request(struct core_name *cn, + struct coredump_params *cprm) { return false; } static inline void coredump_sock_wait(struct file *file) { } static inline void coredump_sock_shutdown(struct file *file) { } #endif @@ -984,80 +1063,11 @@ void do_coredump(const kernel_siginfo_t *siginfo) case COREDUMP_SOCK_REQ: fallthrough; case COREDUMP_SOCK: { -#ifdef CONFIG_UNIX - struct file *file __free(fput) = NULL; - struct sockaddr_un addr = { - .sun_family = AF_UNIX, - }; - ssize_t addr_len; - struct socket *socket; - - addr_len = strscpy(addr.sun_path, cn.corename); - if (addr_len < 0) - goto close_fail; - addr_len += offsetof(struct sockaddr_un, sun_path) + 1; - - /* - * 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) + if (!coredump_sock_connect(&cn, &cprm)) goto close_fail; - file = sock_alloc_file(socket, 0, NULL); - if (IS_ERR(file)) + if (!coredump_sock_request(&cn, &cprm)) goto close_fail; - - /* - * Set the thread-group leader pid which is used for the - * peer credentials during connect() below. Then - * immediately register it in pidfs... - */ - cprm.pid = task_tgid(current); - retval = pidfs_register_pid(cprm.pid); - if (retval) - goto close_fail; - - /* - * ... and set the coredump information so userspace - * has it available after connect()... - */ - pidfs_coredump(&cprm); - - retval = kernel_connect(socket, (struct sockaddr *)(&addr), - addr_len, O_NONBLOCK | SOCK_COREDUMP); - - /* - * ... Make sure to only put our reference after connect() took - * its own reference keeping the pidfs entry alive ... - */ - pidfs_put_pid(cprm.pid); - - if (retval) { - if (retval == -EAGAIN) - coredump_report_failure("Coredump socket %s receive queue full", addr.sun_path); - else - coredump_report_failure("Coredump socket connection %s failed %d", addr.sun_path, retval); - goto close_fail; - } - - /* ... and validate that @sk_peer_pid matches @cprm.pid. */ - if (WARN_ON_ONCE(unix_peer(socket->sk)->sk_peer_pid != cprm.pid)) - goto close_fail; - - cprm.limit = RLIM_INFINITY; - cprm.file = no_free_ptr(file); - - if (!coredump_request(&cn, &cprm)) - goto close_fail; -#else - coredump_report_failure("Core dump socket support %s disabled", cn.corename); - goto close_fail; -#endif break; } default: -- 2.47.2