kernel/linux.git/drivers/usb/core/devio.c, branch v4.14.263

USB: core: Change %pK for __user pointers to %px

2020-12-02T07:34:44+00:00

commit f3bc432aa8a7a2bfe9ebb432502be5c5d979d7fe upstream. Commit 2f964780c03b ("USB: core: replace %p with %pK") used the %pK format specifier for a bunch of __user pointers. But as the 'K' in the specifier indicates, it is meant for kernel pointers. The reason for the %pK specifier is to avoid leaks of kernel addresses, but when the pointer is to an address in userspace the security implications are minimal. In particular, no kernel information is leaked. This patch changes the __user %pK specifiers (used in a bunch of debugging output lines) to %px, which will always print the actual address with no mangling. (Notably, there is no printk format specifier particularly intended for __user pointers.) Fixes: 2f964780c03b ("USB: core: replace %p with %pK") CC: Vamsi Krishna Samavedam CC: Signed-off-by: Alan Stern Link: https://lore.kernel.org/r/20201119170228.GB576844@rowland.harvard.edu Signed-off-by: Greg Kroah-Hartman

usb: usbfs: Suppress problematic bind and unbind uevents.

2019-12-31T11:37:10+00:00

[ Upstream commit abb0b3d96a1f9407dd66831ae33985a386d4200d ] commit 1455cf8dbfd0 ("driver core: emit uevents when device is bound to a driver") added bind and unbind uevents when a driver is bound or unbound to a physical device. For USB devices which are handled via the generic usbfs layer (via libusb for example), this is problematic: Each time a user space program calls ioctl(usb_fd, USBDEVFS_CLAIMINTERFACE, &usb_intf_nr); and then later ioctl(usb_fd, USBDEVFS_RELEASEINTERFACE, &usb_intf_nr); The kernel will now produce a bind or unbind event, which does not really contain any useful information. This allows a user space program to run a DoS attack against programs which listen to uevents (in particular systemd/eudev/upowerd): A malicious user space program just has to call in a tight loop ioctl(usb_fd, USBDEVFS_CLAIMINTERFACE, &usb_intf_nr); ioctl(usb_fd, USBDEVFS_RELEASEINTERFACE, &usb_intf_nr); With this loop the malicious user space program floods the kernel and all programs listening to uevents with tons of bind and unbind events. This patch suppresses uevents for ioctls USBDEVFS_CLAIMINTERFACE and USBDEVFS_RELEASEINTERFACE. Signed-off-by: Ingo Rohloff Link: https://lore.kernel.org/r/20191011115518.2801-1-ingo.rohloff@lauterbach.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

usb: usbfs: fix double-free of usb memory upon submiturb error

2019-08-16T08:13:46+00:00

commit c43f28dfdc4654e738aa6d3fd08a105b2bee758d upstream. Upon an error within proc_do_submiturb(), dec_usb_memory_use_count() gets called once by the error handling tail and again by free_async(). Remove the first call. Signed-off-by: Gavin Li Acked-by: Alan Stern Cc: stable Link: https://lore.kernel.org/r/20190804235044.22327-1-gavinli@thegavinli.com Signed-off-by: Greg Kroah-Hartman

USB: fix the usbfs flag sanitization for control transfers

2018-11-10T15:48:36+00:00

commit 665c365a77fbfeabe52694aedf3446d5f2f1ce42 upstream. Commit 7a68d9fb8510 ("USB: usbdevfs: sanitize flags more") checks the transfer flags for URBs submitted from userspace via usbfs. However, the check for whether the USBDEVFS_URB_SHORT_NOT_OK flag should be allowed for a control transfer was added in the wrong place, before the code has properly determined the direction of the control transfer. (Control transfers are special because for them, the direction is set by the bRequestType byte of the Setup packet rather than direction bit of the endpoint address.) This patch moves code which sets up the allow_short flag for control transfers down after is_in has been set to the correct value. Signed-off-by: Alan Stern Reported-and-tested-by: syzbot+24a30223a4b609bb802e@syzkaller.appspotmail.com Fixes: 7a68d9fb8510 ("USB: usbdevfs: sanitize flags more") CC: Oliver Neukum CC: Signed-off-by: Greg Kroah-Hartman

USB: usbdevfs: restore warning for nonsensical flags

2018-10-04T00:00:56+00:00

commit 81e0403b26d94360abd1f6a57311337973bc82cd upstream. If we filter flags before they reach the core we need to generate our own warnings. Signed-off-by: Oliver Neukum Fixes: 0cb54a3e47cb ("USB: debugging code shouldn't alter control flow") Cc: stable Signed-off-by: Greg Kroah-Hartman

USB: usbdevfs: sanitize flags more

2018-10-04T00:00:56+00:00

commit 7a68d9fb851012829c29e770621905529bd9490b upstream. Requesting a ZERO_PACKET or not is sensible only for output. In the input direction the device decides. Likewise accepting short packets makes sense only for input. This allows operation with panic_on_warn without opening up a local DOS. Signed-off-by: Oliver Neukum Reported-by: syzbot+843efa30c8821bd69f53@syzkaller.appspotmail.com Fixes: 0cb54a3e47cb ("USB: debugging code shouldn't alter control flow") Cc: stable Signed-off-by: Greg Kroah-Hartman

USB: usbfs: Filter flags passed in from user space

2017-12-10T12:40:44+00:00

commit 446f666da9f019ce2ffd03800995487e79a91462 upstream. USBDEVFS_URB_ISO_ASAP must be accepted only for ISO endpoints. Improve sanity checking. Reported-by: Andrey Konovalov Signed-off-by: Oliver Neukum Acked-by: Alan Stern Signed-off-by: Greg Kroah-Hartman

USB: usbfs: compute urb->actual_length for isochronous

2017-11-21T08:49:21+00:00

commit 2ef47001b3ee3ded579b7532ebdcf8680e4d8c54 upstream. The USB kerneldoc says that the actual_length field "is read in non-iso completion functions", but the usbfs driver uses it for all URB types in processcompl(). Since not all of the host controller drivers set actual_length for isochronous URBs, programs using usbfs with some host controllers don't work properly. For example, Minas reports that a USB camera controlled by libusb doesn't work properly with a dwc2 controller. It doesn't seem worthwhile to change the HCDs and the documentation, since the in-kernel USB class drivers evidently don't rely on actual_length for isochronous transfers. The easiest solution is for usbfs to calculate the actual_length value for itself, by adding up the lengths of the individual packets in an isochronous transfer. Signed-off-by: Alan Stern CC: Minas Harutyunyan Reported-and-tested-by: wlf Signed-off-by: Greg Kroah-Hartman

USB: devio: Revert "USB: devio: Don't corrupt user memory"

2017-10-17T08:53:20+00:00

Taking the uurb->buffer_length userspace passes in as a maximum for the actual urbs transfer_buffer_length causes 2 serious issues: 1) It breaks isochronous support for all userspace apps using libusb, as existing libusb versions pass in 0 for uurb->buffer_length, relying on the kernel using the lenghts of the usbdevfs_iso_packet_desc descriptors passed in added together as buffer length. This for example causes redirection of USB audio and Webcam's into virtual machines using qemu-kvm to no longer work. This is a userspace ABI break and as such must be reverted. Note that the original commit does not protect other users / the kernels memory, it only stops the userspace process making the call from shooting itself in the foot. 2) It may cause the kernel to program host controllers to DMA over random memory. Just as the devio code used to only look at the iso_packet_desc lenghts, the host drivers do the same, relying on the submitter of the urbs to make sure the entire buffer is large enough and not checking transfer_buffer_length. But the "USB: devio: Don't corrupt user memory" commit now takes the userspace provided uurb->buffer_length for the buffer-size while copying over the user-provided iso_packet_desc lengths 1:1, allowing the user to specify a small buffer size while programming the host controller to dma a lot more data. (Atleast the ohci, uhci, xhci and fhci drivers do not check transfer_buffer_length for isoc transfers.) This reverts commit fa1ed74eb1c2 ("USB: devio: Don't corrupt user memory") fixing both these issues. Cc: Dan Carpenter Cc: stable@vger.kernel.org Signed-off-by: Hans de Goede Acked-by: Alan Stern Signed-off-by: Greg Kroah-Hartman

USB: devio: Don't corrupt user memory

2017-09-25T08:57:13+00:00

The user buffer has "uurb->buffer_length" bytes. If the kernel has more information than that, we should truncate it instead of writing past the end of the user's buffer. I added a WARN_ONCE() to help the user debug the issue. Reported-by: Alan Stern Cc: stable Signed-off-by: Dan Carpenter Acked-by: Alan Stern Signed-off-by: Greg Kroah-Hartman