From ff917923f4fb9c83717ba135ee47d7e4c1567bb7 Mon Sep 17 00:00:00 2001 From: Muhammad Bilal Date: Tue, 28 Jul 2026 17:54:55 +0500 Subject: staging: rtl8723bs: fix OOB read in rtw_action_frame_parse() rtw_action_frame_parse() takes a frame_len parameter but never actually checks it before indexing into the frame body: const u8 *frame_body = frame + sizeof(struct ieee80211_hdr_3addr); ... c = frame_body[0]; ... a = frame_body[1]; frame_body already points 24 bytes (sizeof(struct ieee80211_hdr_3addr)) into frame, so reading frame_body[0] and frame_body[1] requires frame_len >= 26. A management action frame shorter than that (e.g. exactly 24 bytes, the minimum a malicious peer can send) causes a 1-2 byte out-of-bounds read. This is reachable from rtw_cfg80211_monitor_if_xmit_entry() and cfg80211_rtw_mgmt_tx() in ioctl_cfg80211.c, both of which pass attacker/user-influenced frame buffers and lengths straight through. Add the missing length check before frame_body is dereferenced. Fixes: 554c0a3abf216 ("staging: Add rtl8723bs sdio wifi driver") Cc: stable@vger.kernel.org Signed-off-by: Muhammad Bilal Link: https://patch.msgid.link/20260728125456.32359-3-meatuni001@gmail.com Signed-off-by: Greg Kroah-Hartman --- drivers/firmware/google/cbmem.c | 136 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 136 insertions(+) create mode 100644 drivers/firmware/google/cbmem.c (limited to 'drivers/firmware/google/cbmem.c') diff --git a/drivers/firmware/google/cbmem.c b/drivers/firmware/google/cbmem.c new file mode 100644 index 000000000..4d20477ed --- /dev/null +++ b/drivers/firmware/google/cbmem.c @@ -0,0 +1,136 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * cbmem.c + * + * Driver for exporting cbmem entries in sysfs. + * + * Copyright 2022 Google LLC + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "coreboot_table.h" + +struct cbmem_entry { + char *mem_file_buf; + u32 size; +}; + +static struct cbmem_entry *to_cbmem_entry(struct kobject *kobj) +{ + return dev_get_drvdata(kobj_to_dev(kobj)); +} + +static ssize_t mem_read(struct file *filp, struct kobject *kobj, + const struct bin_attribute *bin_attr, char *buf, loff_t pos, + size_t count) +{ + struct cbmem_entry *entry = to_cbmem_entry(kobj); + + return memory_read_from_buffer(buf, count, &pos, entry->mem_file_buf, + entry->size); +} + +static ssize_t mem_write(struct file *filp, struct kobject *kobj, + const struct bin_attribute *bin_attr, char *buf, loff_t pos, + size_t count) +{ + struct cbmem_entry *entry = to_cbmem_entry(kobj); + + if (pos < 0 || pos >= entry->size) + return -EINVAL; + if (count > entry->size - pos) + count = entry->size - pos; + + memcpy(entry->mem_file_buf + pos, buf, count); + return count; +} +static const BIN_ATTR_ADMIN_RW(mem, 0); + +static ssize_t address_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct coreboot_device *cbdev = dev_to_coreboot_device(dev); + + return sysfs_emit(buf, "0x%llx\n", cbdev->cbmem_entry.address); +} +static DEVICE_ATTR_RO(address); + +static ssize_t size_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct coreboot_device *cbdev = dev_to_coreboot_device(dev); + + return sysfs_emit(buf, "0x%x\n", cbdev->cbmem_entry.entry_size); +} +static DEVICE_ATTR_RO(size); + +static struct attribute *attrs[] = { + &dev_attr_address.attr, + &dev_attr_size.attr, + NULL, +}; + +static const struct bin_attribute *const bin_attrs[] = { + &bin_attr_mem, + NULL, +}; + +static const struct attribute_group cbmem_entry_group = { + .attrs = attrs, + .bin_attrs = bin_attrs, +}; + +static const struct attribute_group *dev_groups[] = { + &cbmem_entry_group, + NULL, +}; + +static int cbmem_entry_probe(struct coreboot_device *dev) +{ + struct cbmem_entry *entry; + + entry = devm_kzalloc(&dev->dev, sizeof(*entry), GFP_KERNEL); + if (!entry) + return -ENOMEM; + + dev_set_drvdata(&dev->dev, entry); + entry->mem_file_buf = devm_memremap(&dev->dev, dev->cbmem_entry.address, + dev->cbmem_entry.entry_size, + MEMREMAP_WB); + if (IS_ERR(entry->mem_file_buf)) + return PTR_ERR(entry->mem_file_buf); + + entry->size = dev->cbmem_entry.entry_size; + + return 0; +} + +static const struct coreboot_device_id cbmem_ids[] = { + { .tag = LB_TAG_CBMEM_ENTRY }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(coreboot, cbmem_ids); + +static struct coreboot_driver cbmem_entry_driver = { + .probe = cbmem_entry_probe, + .drv = { + .name = "cbmem", + .dev_groups = dev_groups, + }, + .id_table = cbmem_ids, +}; +module_coreboot_driver(cbmem_entry_driver); + +MODULE_AUTHOR("Jack Rosenthal "); +MODULE_DESCRIPTION("Driver for exporting CBMEM entries in sysfs"); +MODULE_LICENSE("GPL"); -- cgit v1.3.1