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=1792584894; b=YPjiQwzaaT1rflLioMukbR+dSYaLax38RuC2Hl5Y8+zzifzlFbfhCNUFXNZ2TgWvd7g3 vG+hX2EPcSGQsNCWcKbRPse9I3REE1sPX3DdL08EBxUjUgloU9yrNAnPTNQgyBiPL2z8R dpGc8oktItIp16hgaOgVPnvAaP9i5Hisxid+nICvJ6+XL7nNp0UZMT3hyHj5PRv0NsdPg YS8RTCeZLTKd2Ruf+lMZHjP+5K7gXayfBrJ+Esj0xogCnfsDlssc2IGvmoc5iTuj3KA9K BoIHEvg4P2vJAPHkJRpZq93/ajA95lvuBRjexQVmlyy9swZwtdHpky6AZULQ3OT65Tg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792584894; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=yIE4Ws0+fzmkVfBmC58B4o4iBYgCAB+97otsS2HlOmY=; b=ARb504YWJi3+oIow//B/qUGefg4bqO4ETpZfEwUTaBD47u3Hk6Ufi0g6ZcuS8fbIADf7 j3JIz1ITOuZL9rgMJI+WnfRESWLuXeyKMUiYt8QPsfKPInQF5W/+UHoHqUvP9QqQ9v1pT dnKlSDlWC7FsJqke1PDrS3FVcWAG68bukCoca+HirukoZGYSBbcOQb4aXM1q6GpzOGt/a uT3chQonJUYIIbefMrWi7da72+gXwN98L8N1NsD0Y42+gpKJ4g926XOvUgibUqd3fZNuA VX4brSfZh4Y5LEZWf+xLttXKDv10GpzKYqkEuOkL3E4LDcFoQtMeWIeOecI89Vc1sZA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=MT16dIF5; 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 C5AD4606A334; Wed, 21 Oct 2026 12:14:53 +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=MT16dIF5 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5ECD41F000C5; Wed, 21 Oct 2026 12:14:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792584893; bh=yIE4Ws0+fzmkVfBmC58B4o4iBYgCAB+97otsS2HlOmY=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=MT16dIF5R3rm5ttv3iWHGZfQKfnLzunO0QTri6bfKhnQfJbfnFVRsRebPLx5naONA 6cbT8oJkh4F6TdYpQAZWCpUzwpLeVeQEqvKEbHsQjQ2UK+Sz73DHdPdKiYUxk/7e47 KD7bpCJHs5yTOtp0J6AFt0Ha0gH7hijjKUJqxv17lmi7E2DFj3jVvj6n0uSGdNwRjK 0wHluVC/XZ3X9b3ztMeRdBILVmQ/KA70BrZANnPW9QaR1r90PNjRsiWDzw1sqXkh8W 61UccBQtqgI+DAt91v8rPyjb60InjYMA6rNHXv2DBMHg2YdOCTAAZyDt2A5AiN69Hy RhvQmiBgHxSlA== From: Lee Jones To: lee@kernel.org, Thomas Richard , mfd@lists.linux.dev, linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org Subject: [PATCH 09/28] mfd: cgbc: Zero-initialise version buffer in cgbc_get_version() Date: Wed, 21 Oct 2026 12:09:31 +0000 Message-ID: <20261021121245.3111563-9-lee@kernel.org> X-Mailer: git-send-email 2.56.0.218.g1ec904b173-goog In-Reply-To: <20261021121245.3111563-1-lee@kernel.org> References: <20261021121245.3111563-1-lee@kernel.org> X-Mailing-List: linux-kernel@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 If the Board Controller returns a short response to the firmware revision query in cgbc_get_version(), cgbc_command() can succeed without populating all bytes of the stack-allocated data buffer. Those uninitialised stack bytes are then copied into cgbc->version and exposed to userspace via the cgbc_version sysfs attribute. Zero-initialise the data buffer on the stack to prevent leaking uninitialised kernel stack memory. Fixes: 6f1067cfbee7 ("mfd: Add Congatec Board Controller driver") Closes: https://sashiko.dev/#/bug/linux-8c473713-527e-4619-8404-689f28c7654d Cc: stable@vger.kernel.org Signed-off-by: Lee Jones --- drivers/mfd/cgbc-core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/mfd/cgbc-core.c b/drivers/mfd/cgbc-core.c index 2becaf797646..f2615c783bc8 100644 --- a/drivers/mfd/cgbc-core.c +++ b/drivers/mfd/cgbc-core.c @@ -299,7 +299,7 @@ ATTRIBUTE_GROUPS(cgbc); static int cgbc_get_version(struct cgbc_device_data *cgbc) { u8 cmd = CGBC_CMD_GET_FW_REV; - u8 data[4]; + u8 data[4] = {}; int ret; ret = cgbc_command(cgbc, &cmd, 1, &data, sizeof(data), NULL); -- 2.56.0.218.g1ec904b173-goog