diff options
| author | Muhammad Bilal <meatuni001@gmail.com> | 2026-07-28 17:54:55 +0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2026-09-01 12:15:16 +0200 |
| commit | ff917923f4fb9c83717ba135ee47d7e4c1567bb7 (patch) | |
| tree | c38fd8fcf58e1937b17fdbc6518b6f8b797fc15a /drivers/gpio/TODO | |
| download | linux-stable-ff917923f4fb9c83717ba135ee47d7e4c1567bb7.tar.gz linux-stable-ff917923f4fb9c83717ba135ee47d7e4c1567bb7.zip | |
staging: rtl8723bs: fix OOB read in rtw_action_frame_parse()grafted
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 <meatuni001@gmail.com>
Link: https://patch.msgid.link/20260728125456.32359-3-meatuni001@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/gpio/TODO')
| -rw-r--r-- | drivers/gpio/TODO | 174 |
1 files changed, 174 insertions, 0 deletions
diff --git a/drivers/gpio/TODO b/drivers/gpio/TODO new file mode 100644 index 000000000..7ce80fde1 --- /dev/null +++ b/drivers/gpio/TODO @@ -0,0 +1,174 @@ +This is a place for planning the ongoing long-term work in the GPIO +subsystem. + +=============================================================================== + +GPIO descriptors + +Starting with commit 79a9becda894 the GPIO subsystem embarked on a journey +to move away from the global GPIO numberspace and toward a descriptor-based +approach. This means that GPIO consumers, drivers and machine descriptions +ideally have no use or idea of the global GPIO numberspace that has/was +used in the inception of the GPIO subsystem. + +The numberspace issue is the same as to why irq is moving away from irq +numbers to IRQ descriptors. + +The underlying motivation for this is that the GPIO numberspace has become +unmanageable: machine board files tend to become full of macros trying to +establish the numberspace at compile-time, making it hard to add any numbers +in the middle (such as if you missed a pin on a chip) without the numberspace +breaking. + +Machine descriptions such as device tree or ACPI does not have a concept of the +Linux GPIO number as those descriptions are external to the Linux kernel +and treat GPIO lines as abstract entities. + +The runtime-assigned GPIO numberspace (what you get if you assign the GPIO +base as -1 in struct gpio_chip) has also became unpredictable due to factors +such as probe ordering and the introduction of -EPROBE_DEFER making probe +ordering of independent GPIO chips essentially unpredictable, as their base +number will be assigned on a first come first serve basis. + +The best way to get out of the problem is to make the global GPIO numbers +unimportant by simply not using them. GPIO descriptors deal with this. + +Work items: + +- Convert all GPIO device drivers to only #include <linux/gpio/driver.h> + +- Convert all consumer drivers to only #include <linux/gpio/consumer.h> + +- Convert all machine descriptors in "boardfiles" to only + #include <linux/gpio/machine.h>, the other option being to convert it + to a machine description such as device tree, ACPI or fwnode that + implicitly does not use global GPIO numbers. + +- Fix drivers to not read back struct gpio_chip::base. Some drivers do + that and would be broken by attempts to poison it or make it dynamic. + Example in AT91 pinctrl driver: + https://lore.kernel.org/all/1d00c056-3d61-4c22-bedd-3bae0bf1ddc4@pengutronix.de/ + This particular driver is also DT-only, so with the above fixed, the + base can be made dynamic (set to -1) if CONFIG_GPIO_SYSFS is disabled. + +- When this work is complete (will require some of the items in the + following ongoing work as well) we can delete the old global + numberspace accessors from <linux/gpio.h> and eventually delete + <linux/gpio.h> altogether. + +------------------------------------------------------------------------------- + +Collect drivers + +Collect GPIO drivers from arch/* and other places that should be placed +in drivers/gpio/gpio-*. Augment platforms to create platform devices or +similar and probe a proper driver in the gpiolib subsystem. + +In some cases it makes sense to create a GPIO chip from the local driver +for a few GPIOs. Those should stay where they are. + +At the same time it makes sense to get rid of code duplication in existing or +new coming drivers. For example, gpio-ml-ioh should be incorporated into +gpio-pch. + +------------------------------------------------------------------------------- + +Generic MMIO GPIO + +The GPIO drivers can utilize the generic MMIO helper library in many +cases, and the helper library should be as helpful as possible for MMIO +drivers. (drivers/gpio/gpio-mmio.c) + +Work items: + +- Look over and identify any remaining easily converted drivers and + dry-code conversions to MMIO GPIO for maintainers to test + +- Expand the MMIO GPIO or write a new library for regmap-based I/O + helpers for GPIO drivers on regmap that simply use offsets + 0..n in some register to drive GPIO lines + +- Expand the MMIO GPIO or write a new library for port-mapped I/O + helpers (x86 inb()/outb()) and convert port-mapped I/O drivers to use + this with dry-coding and sending to maintainers to test + +------------------------------------------------------------------------------- + +Generic regmap GPIO + +In the very similar way to Generic MMIO GPIO convert the users which can +take advantage of using regmap over direct IO accessors. Note, even in +MMIO case the regmap MMIO with gpio-regmap.c is preferable over gpio-mmio.c. + +------------------------------------------------------------------------------- + +GPIOLIB irqchip + +The GPIOLIB irqchip is a helper irqchip for "simple cases" that should +try to cover any generic kind of irqchip cascaded from a GPIO. + +- Look over and identify any remaining easily converted drivers and + dry-code conversions to gpiolib irqchip for maintainers to test + +------------------------------------------------------------------------------- + +Moving over to immutable irq_chip structures + +Most of the gpio chips implementing interrupt support rely on gpiolib +intercepting some of the irq_chip callbacks, preventing the structures +from being made read-only and forcing duplication of structures that +should otherwise be unique. + +The solution is to call into the gpiolib code when needed (resource +management, enable/disable or unmask/mask callbacks), and to let the +core code know about that by exposing a flag (IRQCHIP_IMMUTABLE) in +the irq_chip structure. The irq_chip structure can then be made unique +and const. + +A small number of drivers have been converted (pl061, tegra186, msm, +amd, apple), and can be used as examples of how to proceed with this +conversion. Note that drivers using the generic irqchip framework +cannot be converted yet, but watch this space! + +------------------------------------------------------------------------------- + +Remove legacy sysfs features + +We have two parallel per-chip class devices and per-exported-line attribute +groups in sysfs. One is using the obsolete global GPIO numberspace and the +second relies on hardware offsets of pins within the chip. Remove the former +once user-space has switched to using the latter. + +------------------------------------------------------------------------------- + +Remove GPIOD_FLAGS_BIT_NONEXCLUSIVE + +GPIOs in the linux kernel are meant to be an exclusive resource. This means +that the GPIO descriptors (the software representation of the hardware concept) +are not reference counted and - in general - only one user at a time can +request a GPIO line and control its settings. The consumer API is designed +around full control of the line's state as evidenced by the fact that, for +instance, gpiod_set_value() does indeed drive the line as requested, instead +of bumping an enable counter of some sort. + +A problematic use-case for GPIOs is when two consumers want to use the same +descriptor independently. An example of such a user is the regulator subsystem +which may instantiate several struct regulator_dev instances containing +a struct device but using the same enable GPIO line. + +A workaround was introduced in the form of the GPIOD_FLAGS_BIT_NONEXCLUSIVE +flag but its implementation is problematic: it does not provide any +synchronization of usage nor did it introduce any enable count meaning the +non-exclusive users of the same descriptor will in fact "fight" for the +control over it. This flag should be removed and replaced with a better +solution, possibly based on the new power sequencing subsystem. + +------------------------------------------------------------------------------- + +Remove devm_gpiod_unhinge() + +devm_gpiod_unhinge() is provided as a way to transfer the ownership of managed +enable GPIOs to the regulator core. Rather than doing that however, we should +make it possible for the regulator subsystem to deal with GPIO resources the +lifetime of which it doesn't control as logically, a GPIO obtained by a caller +should also be freed by it. |
