From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 A50DC3E8338 for ; Thu, 25 Jun 2026 16:25:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782404712; cv=none; b=L1sBWNEob+U0Xg/AnnIcA7SUsJJJML/MTn78H+Lu8KYF1yRZdCEkvGOTMAOckwnrJDdZzyfy0NFfNYZWumNVOYj5pyyicDJ3yTtTfvTZOAy2vKxjw92/Z2bwG9w1X99gkLvevPZCUzyeRsErgRo8DCdQ7KPEHtiuA+09Bw1Vz3E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782404712; c=relaxed/simple; bh=WLO01jNEoH0zpjfX7J5It0Gy65+srHcO4sw2XiUtlek=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=nGToVEXSuYwoW2uGAaG27MAUY/xaikBsd8/RoDJ3mFmDGGxLk9yhDzlQ1RURaKYT1AqafW+e6gBAY48jEZBHqi489qmASn2dSq/9nqfwD0JtQCwklUPh8V/zCEcCyJNesqqDXFveaJ3vHqm2qJl/OB3dZkwwfb4IKmoxpZJQPmM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=KP7wHTWo; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="KP7wHTWo" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 16D8F1F00A3A; Thu, 25 Jun 2026 16:25:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1782404711; bh=zBu96uLwuXZY8tm4MYdDyDmR2TnH5qzynQEOv4KvVx0=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=KP7wHTWolBcaj+lRrXPkVeTn80PFqcRO+2jlPG/2BvGpADnbhL3yF7zGxglxCBRNS euQfmtNG0/cB/e3/SFGJ7AhoPCr8bvpBaeLxhUGSwFMcnN8nsx4pcMCqhWLI6sR5nT M1SWOYhum3tlGNFCwmllbGJLVa3RMBvJDdZV9eykjt3K4/cJscS/BqlKC/jvjkikOg c/eI1aguLWpcDmbEW3a7vOy6Gq0Tgvtct1gc4Nsiu45JE0jurKsnSdDjDGDdJDIZaJ IZuTckdYOO7ZxU1AlqLrsZmmdRJRvkY5JOAKRelfbZ5QSnLzpY5jByPaBBAYZXETsQ /suIQ9BRQGx8w== From: Sasha Levin To: stable@vger.kernel.org Cc: Dmitry Torokhov , Greg Kroah-Hartman , Sasha Levin Subject: [PATCH 6.12.y 2/2] Input: rmi4 - refactor register descriptor parsing Date: Thu, 25 Jun 2026 12:25:08 -0400 Message-ID: <20260625162508.2501015-2-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260625162508.2501015-1-sashal@kernel.org> References: <2026062528-cyclist-operable-1e2f@gregkh> <20260625162508.2501015-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Dmitry Torokhov [ Upstream commit 0adb483fbf2dc43c875cd7550a58b41e92efc52d ] Factor out parsing a register descriptor item from rmi_read_register_desc() and ensure there are no out-of-bounds accesses. Use get_unaligned_le16() and get_unaligned_le32() for reading multi-byte values. Reported-by: Greg Kroah-Hartman Fixes: 2b6a321da9a2 ("Input: synaptics-rmi4 - add support for Synaptics RMI4 devices") Cc: stable@vger.kernel.org Assisted-by: Gemini:gemini-3.1-pro Link: https://patch.msgid.link/20260505045952.1570713-2-dmitry.torokhov@gmail.com Signed-off-by: Dmitry Torokhov Signed-off-by: Sasha Levin --- drivers/input/rmi4/rmi_driver.c | 124 +++++++++++++++++++------------- 1 file changed, 76 insertions(+), 48 deletions(-) diff --git a/drivers/input/rmi4/rmi_driver.c b/drivers/input/rmi4/rmi_driver.c index ccd9338a44dbef..6a6d1a4e21accf 100644 --- a/drivers/input/rmi4/rmi_driver.c +++ b/drivers/input/rmi4/rmi_driver.c @@ -22,6 +22,7 @@ #include #include #include +#include #include "rmi_bus.h" #include "rmi_driver.h" @@ -558,30 +559,74 @@ int rmi_scan_pdt(struct rmi_device *rmi_dev, void *ctx, return retval < 0 ? retval : 0; } +static int rmi_parse_register_desc_item(struct rmi_register_desc_item *item, + const u8 *buf, size_t size) +{ + unsigned int offset = 0; + unsigned int map_offset = 0; + int b; + + if (offset >= size) + return -EIO; + + item->reg_size = buf[offset++]; + if (item->reg_size == 0) { + if (size - offset < 2) + return -EIO; + item->reg_size = get_unaligned_le16(&buf[offset]); + offset += 2; + } + + if (item->reg_size == 0) { + if (size - offset < 4) + return -EIO; + item->reg_size = get_unaligned_le32(&buf[offset]); + offset += 4; + } + + do { + if (offset >= size) + return -EIO; + + for (b = 0; b < 7; b++) { + if (buf[offset] & BIT(b)) { + if (map_offset >= RMI_REG_DESC_SUBPACKET_BITS) + return -EIO; + __set_bit(map_offset, item->subpacket_map); + } + ++map_offset; + } + } while (buf[offset++] & BIT(7)); + + item->num_subpackets = bitmap_weight(item->subpacket_map, + RMI_REG_DESC_SUBPACKET_BITS); + + return offset; +} + int rmi_read_register_desc(struct rmi_device *d, u16 addr, - struct rmi_register_descriptor *rdesc) + struct rmi_register_descriptor *rdesc) { int ret; u8 size_presence_reg; u8 buf[35]; - int presense_offset = 1; - u8 *struct_buf; - int reg; - int offset = 0; - int map_offset = 0; + unsigned int presence_offset; + unsigned int map_offset; + unsigned int offset; + unsigned int reg; int i; int b; /* * The first register of the register descriptor is the size of - * the register descriptor's presense register. + * the register descriptor's presence register. */ ret = rmi_read(d, addr, &size_presence_reg); if (ret) return ret; ++addr; - if (size_presence_reg < 0 || size_presence_reg > 35) + if (size_presence_reg < 1 || size_presence_reg > 35) return -EIO; memset(buf, 0, sizeof(buf)); @@ -597,16 +642,23 @@ int rmi_read_register_desc(struct rmi_device *d, u16 addr, ++addr; if (buf[0] == 0) { - presense_offset = 3; - rdesc->struct_size = buf[1] | (buf[2] << 8); + if (size_presence_reg < 3) + return -EIO; + presence_offset = 3; + rdesc->struct_size = get_unaligned_le16(&buf[1]); } else { + presence_offset = 1; rdesc->struct_size = buf[0]; } - for (i = presense_offset; i < size_presence_reg; i++) { + map_offset = 0; + for (i = presence_offset; i < size_presence_reg; i++) { for (b = 0; b < 8; b++) { - if (buf[i] & (0x1 << b)) + if (buf[i] & BIT(b)) { + if (map_offset >= RMI_REG_DESC_PRESENSE_BITS) + return -EIO; bitmap_set(rdesc->presense_map, map_offset, 1); + } ++map_offset; } } @@ -626,7 +678,7 @@ int rmi_read_register_desc(struct rmi_device *d, u16 addr, * I'm not using devm_kzalloc here since it will not be retained * after exiting this function */ - struct_buf = kzalloc(rdesc->struct_size, GFP_KERNEL); + u8 *struct_buf __free(kfree) = kzalloc(rdesc->struct_size, GFP_KERNEL); if (!struct_buf) return -ENOMEM; @@ -638,56 +690,32 @@ int rmi_read_register_desc(struct rmi_device *d, u16 addr, */ ret = rmi_read_block(d, addr, struct_buf, rdesc->struct_size); if (ret) - goto free_struct_buff; + return ret; reg = find_first_bit(rdesc->presense_map, RMI_REG_DESC_PRESENSE_BITS); + offset = 0; for (i = 0; i < rdesc->num_registers; i++) { struct rmi_register_desc_item *item = &rdesc->registers[i]; - int reg_size = struct_buf[offset]; - - ++offset; - if (reg_size == 0) { - reg_size = struct_buf[offset] | - (struct_buf[offset + 1] << 8); - offset += 2; - } + int item_size; - if (reg_size == 0) { - reg_size = struct_buf[offset] | - (struct_buf[offset + 1] << 8) | - (struct_buf[offset + 2] << 16) | - (struct_buf[offset + 3] << 24); - offset += 4; - } + item_size = rmi_parse_register_desc_item(item, + &struct_buf[offset], + rdesc->struct_size - offset); + if (item_size < 0) + return item_size; item->reg = reg; - item->reg_size = reg_size; - - map_offset = 0; - - do { - for (b = 0; b < 7; b++) { - if (struct_buf[offset] & (0x1 << b)) - bitmap_set(item->subpacket_map, - map_offset, 1); - ++map_offset; - } - } while (struct_buf[offset++] & 0x80); - - item->num_subpackets = bitmap_weight(item->subpacket_map, - RMI_REG_DESC_SUBPACKET_BITS); + offset += item_size; rmi_dbg(RMI_DEBUG_CORE, &d->dev, "%s: reg: %d reg size: %ld subpackets: %d\n", __func__, item->reg, item->reg_size, item->num_subpackets); reg = find_next_bit(rdesc->presense_map, - RMI_REG_DESC_PRESENSE_BITS, reg + 1); + RMI_REG_DESC_PRESENSE_BITS, reg + 1); } -free_struct_buff: - kfree(struct_buf); - return ret; + return 0; } const struct rmi_register_desc_item *rmi_get_register_desc_item( -- 2.53.0