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=1794061649; b=J2J5SGgKYjbBvdHAgu7i8a5IDK6OihCiuf9lbcSXLM6o+w53vtilfaO6k4VofkEJsgzc BYZpvxOSoOvoAev+a6od5v7937uUMatoDaab9rbuZsYe/LmZ55tIc/lX1uBawjWDfQvHC ZAqQTEdtoau31hCzQ9atv41emwR2Wv/JbuQcacEhJ0sqM0Xld2JOFDKzfjX/sdj22MOva juJUtqHKbRWED1BUdjPag/tQ6a+8/xqOlqChmwammbObQJBa5UipwlKql6kYQnvld0J1Z JOGzdAw8GhmY1sQeFAbHhwsBl1gCkMFBYyUmMicDYJGHw7LGnAWUsMxTCeaJe4lJAXg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794061649; 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=T7aBBXXeUPhAtS69KBxfgf/0TxdRbJSavdhc8090ycc=; b=MpWsWh4pTPq9kpVKicloM9T5X+HF6dNhVk2TWhtu++D3j3BIibYOsHxdeu3ZO816woUx +d0RvXQRMa6UjUVn8pGm4bUz6k1eWuGSfeVkmfy54bjn3oTZ1RkdOybt4sdSJxZp9B3BD 53B2s9IqBCQIdCIxFgkpwZe6H690XCk9qpHy0kPvueN2A7Xp52Tqev7rIrRUjRCv1S7HT zNWTklUTm+08HcLh8wbcmTEAlryvr5pz2i+bK8A0ZnrzfM9Qrg3IxOdwpQOURywRa4Hyc +Mh+XPZjDtI4HUsgi9kaWiQo5M9roozkAXH4KcnyZemo71mRt8FDgHqfywTD+cinQuQ== 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=OCSbi948; 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 B1CE6606A333; Sat, 7 Nov 2026 14:27:28 +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=OCSbi948 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2EDF21F0089F; Sat, 7 Nov 2026 14:27:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1794061648; bh=T7aBBXXeUPhAtS69KBxfgf/0TxdRbJSavdhc8090ycc=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=OCSbi948U9+iQxbPRBESDLziNmi7x+Du7EcEEN/sMHeAWbygKM2CR6atOmLkzUTPt tb7j/ElnFGny3z7w63l8oE3FrfX40rSnQKx6TdBPows7nP+lR1NSGq/J3YkJD+WYTI 5urJ9nNxRr6dL7OnM/WIh3EBGk2ejuoTiI396JKk= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Dmitry Sinyavin , Janne Grunau , Srinivas Kandagatla Subject: [PATCH 6.12 0660/1536] nvmem: core: Fix OOB read for bit offsets of more than one byte Date: Sat, 7 Nov 2026 08:44:36 -0500 Message-ID: <20261107135016.056962130@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261107134957.653319350@linuxfoundation.org> References: <20261107134957.653319350@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 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Janne Grunau commit 24530401e8001aaa637dd5007fcdc6fbc00300be upstream. When the bit offset is BITS_PER_BYTE or larger the read position is advanced by `bytes_offset`. This is not taken into account in the per-byte read loop which still reads `cell->bytes` resulting in an out of bounds read of `bytes_offset` bytes. The information read OOB does not leak directly as the erroneously read bits are cleared. Detected by KASAN while looking for a use-after-free in simplefb.c. Cc: stable@vger.kernel.org Fixes: 7a06ef751077 ("nvmem: core: fix bit offsets of more than one byte") Tested-by: Dmitry Sinyavin Signed-off-by: Janne Grunau Signed-off-by: Srinivas Kandagatla Link: https://patch.msgid.link/20261002101329.1084348-5-srini@kernel.org Signed-off-by: Greg Kroah-Hartman Signed-off-by: Greg Kroah-Hartman --- drivers/nvmem/core.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/drivers/nvmem/core.c +++ b/drivers/nvmem/core.c @@ -1626,12 +1626,14 @@ static void nvmem_shift_read_buffer_in_p *p = *b++ >> bit_offset; /* setup rest of the bytes if any */ - for (i = 1; i < cell->bytes; i++) { + for (i = 1; i < (cell->bytes - bytes_offset); i++) { /* Get bits from next byte and shift them towards msb */ *p++ |= *b << (BITS_PER_BYTE - bit_offset); *p = *b++ >> bit_offset; } + /* point to end of the buffer unused bits will be cleared */ + p = buf + cell->bytes - 1; } else if (p != b) { memmove(p, b, cell->bytes - bytes_offset); p += cell->bytes - 1;