From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794063173; b=3QhtAynOnKk2WUvqUSdwrlg3uDLZShB0kttGhRm6UlIf2pJoRIMxfe8B96z1KpIoLNG6 iFadn8l0xtT1ukyMBjQihAXTr8oiivVHglwxrpUuLlWU3W2rqxzGWShtPv3QyrFlLkYHx 33Qafg3OIOJSnjYQZuSpzlOMTE/9k6m/hLrSt3WHENWCiDCZtnKSZObC031kLSzWHo/lO nYhze0AXNvMHBIA0VgpH0VoWHWr1JmOMFiVGR0yt01oLPeTPkPxUXkwyrQs/1HggPvgsg aLpE6PrARCnORCZ5Z5GonIW9nELFQDxkEW4LTriscTnEiPHtk9sQMIujCtInfX0oSLg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794063173; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=lpBB73T332H1q44qIZWwCM24m+9+spH0ha3iEmqHWwk=; b=0cRTqXm5gIBjj+QVm7NOnH2m+ayvHF97R6rNDsLdAXW1Gg9V0IxLhpPMw6JaPT0lWG6z qfk6nTO6gbbUbIALT477moKkEfo+siuKn3SqxCRQQ+5YLSbcGTSrh1vHEuvd4s5rZgYjF jDL6BybHtmZRco9dNNZ0Yr3L/FyiDUphUinlJd9Fm3X6Rsi0ab5C6DxTv1eNqnc82EOL/ 1iq0N/nXs8ABN//SYsAWoX50+yb1a9bE5D1/Ejh1dDbBB6DmmsA0l1VFCTdDsCuXqgAWx PVYxKVLLjkAOkehcH51m0dWjyB2FlKasbfJsUwYzloJozcB4doR60PhNQf7hiez0Aew== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=TEg2Xxel; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BC4FD606D802; Sat, 7 Nov 2026 14:52:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=TEg2Xxel Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6A0121F0089F; Sat, 7 Nov 2026 14:52:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1794063172; bh=lpBB73T332H1q44qIZWwCM24m+9+spH0ha3iEmqHWwk=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=TEg2XxelUfV/TCjiMVUPDlxxgCnXA4RdRe1YGf7QmBx9u4mKE15qUysk2/7wT3YtR VGmM4rK/3lNC6EIoxM71mtJnAroCMd+gQdxI2STtn2mpyYvfh+jwwsZOpGIyrAgChE Lf+zKkizDoMKg8i40sZZ4Vxtp7iRaHaUGHxF/7nw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Thorsten Blum , Andrew Morton , Dan Moulding , Sasha Levin Subject: [PATCH 6.18 390/869] init: fix early boot crash with bare hostname parameter Date: Sat, 7 Nov 2026 08:51:12 -0500 Message-ID: <20261107134906.657095154@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261107134852.069646174@linuxfoundation.org> References: <20261107134852.069646174@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Thorsten Blum [ Upstream commit b6bec5b63a5b812145e53aaad1e63661c7214f93 ] When a bare hostname parameter is specified on the kernel command line without the '=' separator, early parameter parsing passes NULL to early_hostname(), which dereferences it in strscpy() and can crash the system during early boot. Reject NULL values in early_hostname() and return -EINVAL instead. Link: https://lore.kernel.org/20260826100904.296151-2-blum@kernel.org Fixes: 5a704629f2c1 ("init: add "hostname" kernel parameter") Signed-off-by: Thorsten Blum Signed-off-by: Andrew Morton Cc: Dan Moulding Cc: Signed-off-by: Sasha Levin --- init/version.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/init/version.c b/init/version.c index 94c96f6fbfe6a..0bd5c45aabc46 100644 --- a/init/version.c +++ b/init/version.c @@ -23,6 +23,9 @@ static int __init early_hostname(char *arg) size_t maxlen = bufsize - 1; ssize_t arglen; + if (!arg) + return -EINVAL; + arglen = strscpy(init_uts_ns.name.nodename, arg, bufsize); if (arglen < 0) { pr_warn("hostname parameter exceeds %zd characters and will be truncated", -- 2.53.0