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![]() Some modules call config_item_init_type_name() and config_group_init_type_name() with parameter "name" directly controlled by userspace. These two functions call config_item_set_name() with this name used as a format string, which can be used to leak information such as content of the stack to userspace. For example, make_netconsole_target() in netconsole module calls config_item_init_type_name() with the name of a newly-created directory. This means that the following commands give some unexpected output, with configfs mounted in /sys/kernel/config/ and on a system with a configured eth0 ethernet interface: # modprobe netconsole # mkdir /sys/kernel/config/netconsole/target_%lx # echo eth0 > /sys/kernel/config/netconsole/target_%lx/dev_name # echo 1 > /sys/kernel/config/netconsole/target_%lx/enabled # echo eth0 > /sys/kernel/config/netconsole/target_%lx/dev_name # dmesg |tail -n1 [ 142.697668] netconsole: target (target_ffffffffc0ae8080) is enabled, disable to update parameters The directory name is correct but %lx has been interpreted in the internal item name, displayed here in the error message used by store_dev_name() in drivers/net/netconsole.c. To fix this, update every caller of config_item_set_name to use "%s" when operating on untrusted input. This issue was found using -Wformat-security gcc flag, once a __printf attribute has been added to config_item_set_name(). Signed-off-by: Nicolas Iooss <nicolas.iooss_linux@m4x.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Felipe Balbi <balbi@ti.com> Acked-by: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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atm | ||
c67x00 | ||
chipidea | ||
class | ||
common | ||
core | ||
dwc2 | ||
dwc3 | ||
early | ||
gadget | ||
host | ||
image | ||
isp1760 | ||
misc | ||
mon | ||
musb | ||
phy | ||
renesas_usbhs | ||
serial | ||
storage | ||
usbip | ||
wusbcore | ||
Kconfig | ||
Makefile | ||
README | ||
usb-skeleton.c |
To understand all the Linux-USB framework, you'll use these resources: * This source code. This is necessarily an evolving work, and includes kerneldoc that should help you get a current overview. ("make pdfdocs", and then look at "usb.pdf" for host side and "gadget.pdf" for peripheral side.) Also, Documentation/usb has more information. * The USB 2.0 specification (from www.usb.org), with supplements such as those for USB OTG and the various device classes. The USB specification has a good overview chapter, and USB peripherals conform to the widely known "Chapter 9". * Chip specifications for USB controllers. Examples include host controllers (on PCs, servers, and more); peripheral controllers (in devices with Linux firmware, like printers or cell phones); and hard-wired peripherals like Ethernet adapters. * Specifications for other protocols implemented by USB peripheral functions. Some are vendor-specific; others are vendor-neutral but just standardized outside of the www.usb.org team. Here is a list of what each subdirectory here is, and what is contained in them. core/ - This is for the core USB host code, including the usbfs files and the hub class driver ("hub_wq"). host/ - This is for USB host controller drivers. This includes UHCI, OHCI, EHCI, and others that might be used with more specialized "embedded" systems. gadget/ - This is for USB peripheral controller drivers and the various gadget drivers which talk to them. Individual USB driver directories. A new driver should be added to the first subdirectory in the list below that it fits into. image/ - This is for still image drivers, like scanners or digital cameras. ../input/ - This is for any driver that uses the input subsystem, like keyboard, mice, touchscreens, tablets, etc. ../media/ - This is for multimedia drivers, like video cameras, radios, and any other drivers that talk to the v4l subsystem. ../net/ - This is for network drivers. serial/ - This is for USB to serial drivers. storage/ - This is for USB mass-storage drivers. class/ - This is for all USB device drivers that do not fit into any of the above categories, and work for a range of USB Class specified devices. misc/ - This is for all USB device drivers that do not fit into any of the above categories.