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smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=IGhyitu5; 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 780C5606BDCB; Wed, 4 Nov 2026 17:50:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=IGhyitu5 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8EC531F00919; Wed, 4 Nov 2026 17:49:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793814616; bh=Ayyh3GSY9IX8l/NxmtUwOJrSt8ohKQ1xsnTJeKuAZFg=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=IGhyitu5c+TLBGkN2ZGwDU5Rsh1w/dzPMJRviHA5R0mqU+LsoYuTVg18Jscu2+6e9 Bde/aMBOPoYzdl/OGhbYhq2RMksr0qSkO6OBBKfsIB2QpTbcfD5O1d7DOOn6y0WboD luv6dPR8E2zuVmQwRu6+4E313LCJ0DI7VA+RNwygcTxJ2P+0Zxk4UQl+ViD8uLTSyj 0Bj56pQlnnoENGhH5tM4j+e/k88FvtR06w4zxZ0OD2mDGN5+rEvzwyzh17+R2wIXby my99TU5Vz2jDt+TrjxUCacOsyHguhDC7NltTczyRHXx91ZO5qtVY+n6qU6a+sO5L4R ZOW5mHfdcdKFg== From: Christian Brauner To: linux-fsdevel@vger.kernel.org Cc: Linus Torvalds , Jann Horn , Josef Bacik , Chris Mason , Jeff Layton , NeilBrown , Eric Dumazet , Thomas Gleixner , Al Viro , Jonathan Corbet , Christoph Hellwig , Greg Kroah-Hartman , Joel Granados , Kees Cook , Jan Kara , Jan Kara , linux-kernel@vger.kernel.org, linux-nfs@vger.kernel.org, linux-acpi@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-s390@vger.kernel.org, linux-scsi@vger.kernel.org, linux-um@lists.infradead.org, linux-wireless@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, netdev@vger.kernel.org, ntfs3@lists.linux.dev, platform-driver-x86@vger.kernel.org, coreteam@netfilter.org, kexec@lists.infradead.org, linux-pci@vger.kernel.org, linux-sound@vger.kernel.org, netfilter-devel@vger.kernel.org, dri-devel@lists.freedesktop.org, ibm-acpi-devel@lists.sourceforge.net, jfs-discussion@lists.sourceforge.net, linux-alpha@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-cifs@vger.kernel.org, linux-fbdev@vger.kernel.org, linux-hwmon@vger.kernel.org, linux-mm@kvack.org, linux-sh@vger.kernel.org, linux-usb@vger.kernel.org, samba-technical@lists.samba.org, sparclinux@vger.kernel.org, linux-m68k@lists.linux-m68k.org, linux-doc@vger.kernel.org, linux-serial@vger.kernel.org, linux-atm-general@lists.sourceforge.net, Takashi Iwai , linux-input@vger.kernel.org, linux-raid@vger.kernel.org, linux-ext4@vger.kernel.org, linux-modules@vger.kernel.org, linux-debuggers@vger.kernel.org, "Christian Brauner (Amutable)" , Chuck Lever , stable@vger.kernel.org Subject: [PATCH v2 20/51] powerpc/rtas_flash: don't read past the validate message Date: Wed, 4 Nov 2026 18:47:06 +0100 Message-ID: <20261104-work-procfs-bugfixes-v2-20-bbf7d5546809@kernel.org> In-Reply-To: <20261104-work-procfs-bugfixes-v2-0-bbf7d5546809@kernel.org> References: <20261104-work-procfs-bugfixes-v2-0-bbf7d5546809@kernel.org> X-Mailing-List: linux-wireless@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" X-Mailer: b4 0.17-dev X-Developer-Signature: v=1; a=openpgp-sha256; l=1303; i=brauner@kernel.org; h=from:subject:message-id; bh=7JHU1Fe1PUKfNakrIeb+3f7MU5rT/9SRwlQjBFg57NM=; b=owGbwMvMwCU28Zj0gdSKO4sYT6slMWS9zru+45fmhHOmCTv0/xXyljhu8Ir9cn6xZ2brsiN/Z jmlm2+821HKwiDGxSArpsji0G4SLrecp2KzUaYGzBxWJpAhDFycAjCRKEaG//GPri/6rCTy5+J8 1kMXe3b3xt9+LRAy/bux8ZXk+aLWoroM//OvT312ZfeyeUVOzxsmOu8P7DVL+ub/7E+HuUjwFae yubwA X-Developer-Key: i=brauner@kernel.org; a=openpgp; fpr=4880B8C9BD0E5106FC070F4F7B3C391EFEA93624 Content-Transfer-Encoding: 8bit get_validate_flash_msg() adds up what snprintf() returns, which is the length of the whole string and not what fit into msg. If the update results the firmware hands back don't fit into what is left of the 256 bytes, the length ends up larger than msg and validate_flash_read() copies whatever follows it on the stack to userspace. Use scnprintf(). Fixes: a94a14720eaf ("powerpc/rtas_flash: Fix validate_flash buffer overflow issue") Cc: stable@vger.kernel.org Signed-off-by: Christian Brauner (Amutable) --- arch/powerpc/kernel/rtas_flash.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/powerpc/kernel/rtas_flash.c b/arch/powerpc/kernel/rtas_flash.c index 722dbfb6fbf8..f1cd105f7426 100644 --- a/arch/powerpc/kernel/rtas_flash.c +++ b/arch/powerpc/kernel/rtas_flash.c @@ -448,7 +448,7 @@ static int get_validate_flash_msg(struct rtas_validate_flash_t *args_buf, n = sprintf(msg, "%d\n", args_buf->update_results); if ((args_buf->update_results >= VALIDATE_CUR_UNKNOWN) || (args_buf->update_results == VALIDATE_TMP_UPDATE)) - n += snprintf(msg + n, msglen - n, "%s\n", + n += scnprintf(msg + n, msglen - n, "%s\n", args_buf->buf); } else { n = sprintf(msg, "%d\n", args_buf->status); -- 2.53.0