From patchwork Mon Apr 14 09:53:37 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christian Brauner X-Patchwork-Id: 14050076 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 DBC41269836; Mon, 14 Apr 2025 09:54:02 +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=1744624443; cv=none; b=SAOqVRGv3KWdj+3iyCsXp2glesX4Cyb/SLbFOM0He1tGhQ/uFnBJjo+igzLOyt+NfQv8CeM63jhTsuLth1YCgJiemVagtqJKV9d6RRKsi/JGvvdxFd30syScfCd3q+QfeOCuOGVJKZ4HP4ByFEYuYBgpTUKVvKlFln1oRCfiJyA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744624443; c=relaxed/simple; bh=Yx0s+29+fWiKG5e4fyOCBvG2yH0V+I1OL3c1XfGljr8=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=J9lyL7SdTaVgTfscAeFsip7YcbTyCHwt8FG3SvQN+6oupWFTTCdqpLqlq6723mhtU8dPWWI+6PtUH3XtIW/8Uz6yLdEB7rmkKOKQpGXgdGi6NJMXaH/Iow73YsyRWT+dJg0rjPhT+TcvSVXBjeoOWSWpRapg72UNum9St8INVJI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=RKTDHglf; 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="RKTDHglf" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 638DAC4CEE2; Mon, 14 Apr 2025 09:54:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1744624442; bh=Yx0s+29+fWiKG5e4fyOCBvG2yH0V+I1OL3c1XfGljr8=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=RKTDHglfBRaRk7Z1UhTKUaSYsds+HamSNpTvpeIkZ6BQEo2Xbk5B94ov3jXtVtGBK umErYL1uABCcLXxmZXcw0TcnpYgP5ikIp81TucCnstpanuO906Sw1RY5OoJNmBe4GR bD2I9WFBHU3V6oWwZfo8O9l61BjFiLewP1J9vHdLbTAMCUIO+VRl25gJHRHpkq1XSg kLBVYOUPvWcIyPSv0QOBa7SsWYEfiAIC4L4yW+UYKuuw7oUwrNz/anCALT4tnwIAQL ccnA6WFuQsiVDAfqcDVxLCLgIQ99XwNuWbYnsDFGzMBlE3grqUl4hSYiPTI6JeX8DJ ptzCXHBQTddDA== From: Christian Brauner Date: Mon, 14 Apr 2025 11:53:37 +0200 Subject: [PATCH 2/3] coredump: fix error handling for replace_fd() Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20250414-work-coredump-v1-2-6caebc807ff4@kernel.org> References: <20250414-work-coredump-v1-0-6caebc807ff4@kernel.org> In-Reply-To: <20250414-work-coredump-v1-0-6caebc807ff4@kernel.org> To: linux-fsdevel@vger.kernel.org Cc: Oleg Nesterov , Luca Boccassi , Lennart Poettering , Daan De Meyer , Mike Yuan , =?utf-8?q?Zbigniew_J=C4=99drzejewski-Szmek?= , linux-kernel@vger.kernel.org, Christian Brauner X-Mailer: b4 0.15-dev-c25d1 X-Developer-Signature: v=1; a=openpgp-sha256; l=1244; i=brauner@kernel.org; h=from:subject:message-id; bh=Yx0s+29+fWiKG5e4fyOCBvG2yH0V+I1OL3c1XfGljr8=; b=owGbwMvMwCU28Zj0gdSKO4sYT6slMaT/uW08eVr2OrPvHOuu/y7Y92Nf7u/HQXrMbN1yNiHan OXTNfUvdpSyMIhxMciKKbI4tJuEyy3nqdhslKkBM4eVCWQIAxenAExEVY3hN9vU3r+h9bts9rPb y/G1rS06ssw/6oOWgVne3sadrUIKpxgZtj4IivTP4zs1mSmo5MZxhfNd4X9KchL+ba0L4ZOvlP/ HBgA= X-Developer-Key: i=brauner@kernel.org; a=openpgp; fpr=4880B8C9BD0E5106FC070F4F7B3C391EFEA93624 The replace_fd() helper returns the file descriptor number on success and a negative error code on failure. The current error handling in umh_pipe_setup() only works because the file descriptor that is replaced is zero but that's pretty volatile. Explicitly check for a negative error code. Tested-by: Luca Boccassi Signed-off-by: Christian Brauner --- fs/coredump.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/fs/coredump.c b/fs/coredump.c index c33c177a701b..2ed5e6956a09 100644 --- a/fs/coredump.c +++ b/fs/coredump.c @@ -507,7 +507,9 @@ static int umh_pipe_setup(struct subprocess_info *info, struct cred *new) { struct file *files[2]; struct coredump_params *cp = (struct coredump_params *)info->data; - int err = create_pipe_files(files, 0); + int err; + + err = create_pipe_files(files, 0); if (err) return err; @@ -515,6 +517,9 @@ static int umh_pipe_setup(struct subprocess_info *info, struct cred *new) err = replace_fd(0, files[0], 0); fput(files[0]); + if (err < 0) + return err; + /* and disallow core files too */ current->signal->rlim[RLIMIT_CORE] = (struct rlimit){1, 1};