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path: root/drivers/usb/misc/chaoskey.c
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2022-11-18hwrng: core - treat default_quality as a maximum and default to 1024Jason A. Donenfeld1-1/+0
Most hw_random devices return entropy which is assumed to be of full quality, but driver authors don't bother setting the quality knob. Some hw_random devices return less than full quality entropy, and then driver authors set the quality knob. Therefore, the entropy crediting should be opt-out rather than opt-in per-driver, to reflect the actual reality on the ground. For example, the two Raspberry Pi RNG drivers produce full entropy randomness, and both EDK2 and U-Boot's drivers for these treat them as such. The result is that EFI then uses these numbers and passes the to Linux, and Linux credits them as boot, thereby initializing the RNG. Yet, in Linux, the quality knob was never set to anything, and so on the chance that Linux is booted without EFI, nothing is ever credited. That's annoying. The same pattern appears to repeat itself throughout various drivers. In fact, very very few drivers have bothered setting quality=1024. Looking at the git history of existing drivers and corresponding mailing list discussion, this conclusion tracks. There's been a decent amount of discussion about drivers that set quality < 1024 -- somebody read and interepreted a datasheet, or made some back of the envelope calculation somehow. But there's been very little, if any, discussion about most drivers where the quality is just set to 1024 or unset (or set to 1000 when the authors misunderstood the API and assumed it was base-10 rather than base-2); in both cases the intent was fairly clear of, "this is a hardware random device; it's fine." So let's invert this logic. A hw_random struct's quality knob now controls the maximum quality a driver can produce, or 0 to specify 1024. Then, the module-wide switch called "default_quality" is changed to represent the maximum quality of any driver. By default it's 1024, and the quality of any particular driver is then given by: min(default_quality, rng->quality ?: 1024); This way, the user can still turn this off for weird reasons (and we can replace whatever driver-specific disabling hacks existed in the past), yet we get proper crediting for relevant RNGs. Cc: Dominik Brodowski <linux@dominikbrodowski.net> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-11-11USB: chaoskey: fix error case of a timeoutOliver Neukum1-3/+21
In case of a timeout or if a signal aborts a read communication with the device needs to be ended lest we overwrite an active URB the next time we do IO to the device, as the URB may still be active. Signed-off-by: Oliver Neukum <oneukum@suse.de> Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20191107142856.16774-1-oneukum@suse.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-10USB: chaoskey: fix use-after-free on releaseJohan Hovold1-2/+3
The driver was accessing its struct usb_interface in its release() callback without holding a reference. This would lead to a use-after-free whenever the device was disconnected while the character device was still open. Fixes: 66e3e591891d ("usb: Add driver for Altus Metrum ChaosKey device (v2)") Cc: stable <stable@vger.kernel.org> # 4.1 Signed-off-by: Johan Hovold <johan@kernel.org> Link: https://lore.kernel.org/r/20191009153848.8664-3-johan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-22USB: chaoskey: Use kasprintf() over strcpy()/strcat()Kees Cook1-6/+2
Instead of kmalloc() with manually calculated values followed by multiple strcpy()/strcat() calls, just fold it all into a single kasprintf() call. Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Keith Packard <keithp@keithp.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-24USB: misc: chaoskey: Use true and false for boolean valuesGustavo A. R. Silva1-3/+3
Assign true or false to boolean variables instead of an integer value. This issue was detected with the help of Coccinelle. Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Reviewed-by: Keith Packard <keithp@keithp.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-04USB: misc: Remove redundant license textGreg Kroah-Hartman1-9/+0
Now that the SPDX tag is in all USB files, that identifies the license in a specific and legally-defined manner. So the extra GPL text wording can be removed as it is no longer needed at all. This is done on a quest to remove the 700+ different ways that files in the kernel describe the GPL license text. And there's unneeded stuff like the address (sometimes incorrect) for the FSF which is never needed. No copyright headers or other non-license-description text was removed. Cc: Keith Packard <keithp@keithp.com> Cc: Juergen Stuber <starblue@users.sourceforge.net> Cc: Cesar Miquel <miquel@df.uba.ar> Cc: Richard Leitner <richard.leitner@skidata.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-04USB: add SPDX identifiers to all remaining files in drivers/usb/Greg Kroah-Hartman1-0/+1
It's good to have SPDX identifiers in all files to make it easier to audit the kernel tree for correct licenses. Update the drivers/usb/ and include/linux/usb* files with the correct SPDX license identifier based on the license text in the file itself. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This work is based on a script and data from Thomas Gleixner, Philippe Ombredanne, and Kate Stewart. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: Philippe Ombredanne <pombredanne@nexb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Felipe Balbi <felipe.balbi@linux.intel.com> Acked-by: Johan Hovold <johan@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-22USB: misc: remove unneeded MODULE_VERSION() usageGreg Kroah-Hartman1-2/+0
MODULE_VERSION is useless for in-kernel drivers, so just remove all usage of it in the USB misc drivers. Along with this, some DRIVER_VERSION macros were removed as they are also pointless. Cc: Keith Packard <keithp@keithp.com> Cc: Juergen Stuber <starblue@users.sourceforge.net> Cc: Cesar Miquel <miquel@df.uba.ar> Acked-by: Richard Leitner <richard.leitner@skidata.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-17USB: chaoskey: fix Alea quirk on big-endian hostsJohan Hovold1-1/+1
Add missing endianness conversion when applying the Alea timeout quirk. Found using sparse: warning: restricted __le16 degrades to integer Fixes: e4a886e811cd ("hwrng: chaoskey - Fix URB warning due to timeout on Alea") Cc: stable <stable@vger.kernel.org> # 4.8 Cc: Bob Ham <bob.ham@collabora.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Keith Packard <keithp@keithp.com> Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-23USB: chaoskey: refactor endpoint retrievalJohan Hovold1-12/+10
Use the new endpoint helpers to lookup the required bulk-in endpoint. Signed-off-by: Johan Hovold <johan@kernel.org> Reviewed-by: Keith Packard <keithp@keithp.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-10-24hwrng: chaoskey - drop workaround for old hwrng core limitationJulien Cristau1-13/+1
The hwrng core used to mask 'quality' with 1023; that has been removed in commit 506bf0c0464ace57169aadcf02ae397999c57bdd ("hwrng: core - allow perfect entropy from hardware devices"), so we can now just set quality to 1024. Signed-off-by: Julien Cristau <jcristau@debian.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-07hwrng: chaoskey - Fix URB warning due to timeout on AleaBob Ham1-2/+15
The first read on an Alea takes about 1.8 seconds, more than the timeout value waiting for the read. As a consequence, later URB reuse causes the warning given below. To avoid this, we increase the wait time for the first read on the Alea. [ 78.293247] WARNING: CPU: 3 PID: 1892 at drivers/usb/core/urb.c:338 usb_submit_urb+0x2b4/0x580 [usbcore] [ 78.293250] URB ffff8802135be3c0 submitted while active [ 78.293252] Modules linked in: chaoskey(+) rng_core rfcomm binfmt_misc bnep cfg80211 nfsd auth_rpcgss oid_registry nfs_acl nfs lockd grace fscache sunrpc bridge stp llc tun snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_codec_generic iTCO_wdt iTCO_vendor_support nls_utf8 nls_cp437 vfat fat intel_rapl x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel efi_pstore kvm irqbypass pcspkr btusb btrtl btbcm btintel uvcvideo joydev bluetooth videobuf2_vmalloc videobuf2_memops efivars videobuf2_v4l2 serio_raw i2c_i801 videobuf2_core videodev cdc_mbim media lpc_ich shpchp mfd_core cdc_ncm usbnet mii cdc_wdm cdc_acm evdev snd_hda_intel snd_hda_codec snd_hwdep snd_hda_core i915 snd_pcm snd_timer i2c_algo_bit drm_kms_helper wmi thinkpad_acpi drm nvram mei_me mei snd soundcore rfkill ac battery i2c_core [ 78.293335] video button tpm_tis tpm fuse parport_pc ppdev lp parport autofs4 ext4 crc16 jbd2 mbcache algif_skcipher af_alg hid_generic usbhid hid dm_crypt dm_mod sg sr_mod cdrom sd_mod crct10dif_pclmul crc32_pclmul crc32c_intel jitterentropy_rng sha256_generic hmac drbg aesni_intel xhci_pci aes_x86_64 ahci glue_helper xhci_hcd ehci_pci lrw libahci gf128mul ablk_helper cryptd libata sdhci_pci psmouse sdhci scsi_mod ehci_hcd mmc_core usbcore usb_common thermal [ 78.293402] CPU: 3 PID: 1892 Comm: hwrng Not tainted 4.7.0-rc1-linux-14+ #16 [ 78.293405] Hardware name: LENOVO 232577G/232577G, BIOS G2ET92WW (2.52 ) 02/22/2013 [ 78.293408] 0000000000000000 ffffffff812dfa0f ffff8801fa5b3d68 0000000000000000 [ 78.293413] ffffffff81072224 ffff8802135be3c0 ffff8801fa5b3db8 ffff880212e44210 [ 78.293418] 0000000000000040 ffff880209fb32c0 ffff880212e44200 ffffffff8107228f [ 78.293422] Call Trace: [ 78.293432] [<ffffffff812dfa0f>] ? dump_stack+0x5c/0x7d [ 78.293437] [<ffffffff81072224>] ? __warn+0xc4/0xe0 [ 78.293441] [<ffffffff8107228f>] ? warn_slowpath_fmt+0x4f/0x60 [ 78.293451] [<ffffffff810a46a2>] ? enqueue_task_fair+0xcd2/0x1260 [ 78.293463] [<ffffffffa001ec54>] ? usb_submit_urb+0x2b4/0x580 [usbcore] [ 78.293474] [<ffffffff8140c2e5>] ? __pm_runtime_resume+0x55/0x70 [ 78.293484] [<ffffffffa0825212>] ? _chaoskey_fill+0x132/0x250 [chaoskey] [ 78.293485] usbcore: registered new interface driver chaoskey [ 78.293493] [<ffffffff810aed50>] ? wait_woken+0x90/0x90 [ 78.293500] [<ffffffffa06448c0>] ? devm_hwrng_register+0x80/0x80 [rng_core] [ 78.293505] [<ffffffffa0825907>] ? chaoskey_rng_read+0x127/0x140 [chaoskey] [ 78.293511] [<ffffffffa06448c0>] ? devm_hwrng_register+0x80/0x80 [rng_core] [ 78.293515] [<ffffffffa064492e>] ? hwrng_fillfn+0x6e/0x120 [rng_core] [ 78.293520] [<ffffffff8108fb5f>] ? kthread+0xcf/0xf0 [ 78.293529] [<ffffffff81596d5f>] ? ret_from_fork+0x1f/0x40 [ 78.293535] [<ffffffff8108fa90>] ? kthread_park+0x50/0x50 Signed-off-by: Bob Ham <bob.ham@collabora.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-06-07hwrng: chaoskey - Add support for Araneus Alea I USB RNGBob Ham1-0/+4
Adds support for the Araneus Alea I USB hardware Random Number Generator which is interfaced with in exactly the same way as the Altus Metrum ChaosKey. We just add the appropriate device ID and modify the config help text. Signed-off-by: Bob Ham <bob.ham@collabora.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-02-21usb/misc/chaoskey: introduce an URB for asynchronous readsOliver Neukum1-21/+65
To allow for and clean handling of signals an URB is introduced. Signed-off-by: Oliver Neukum <oneukum@suse.com> Signed-off-by: Keith Packard <keithp@keithp.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-21usb/misc/chaoskey: Cleanup probe failure pathsOliver Neukum1-18/+18
Shares the cleanup code between all probe failure paths, instead of having per-failure cleanup at each point in the function. Signed-off-by: Oliver Neukum <oneukum@suse.com> Signed-off-by: Keith Packard <keithp@keithp.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04USB: chaoskey read offset bugAlexander Inyukhin1-1/+1
Rng reads in chaoskey driver could return the same data under the certain conditions. Signed-off-by: Alexander Inyukhin <shurick@sectorb.msk.ru> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-04-01usb: Fix warnings in chaoskey driverKeith Packard1-2/+4
> drivers/usb/misc/chaoskey.c: In function 'chaoskey_read': > >> drivers/usb/misc/chaoskey.c:412:3: error: implicit declaration of function 'copy_to_user' > >> [-Werror=implicit-function-declaration] > remain = copy_to_user(buffer, dev->buf + dev->used, this_time); I was unable to reproduce this locally, but added an explicit #include <linux/uaccess.h> which should ensure the definition on all architectures. > sparse warnings: (new ones prefixed by >>) > > >> drivers/usb/misc/chaoskey.c:117:30: sparse: incorrect type in assignment (different base types) > drivers/usb/misc/chaoskey.c:117:30: expected int [signed] size > drivers/usb/misc/chaoskey.c:117:30: got restricted __le16 [usertype] wMaxPacketSize Switched the code to using the USB descriptor accessor functions. Signed-off-by: Keith Packard <keithp@keithp.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-26usb: Add driver for Altus Metrum ChaosKey device (v2)Keith Packard1-0/+530
This is a hardware random number generator. The driver provides both a /dev/chaoskeyX entry and hooks the entropy source up to the kernel hwrng interface. More information about the device can be found at http://chaoskey.org The USB ID for ChaosKey was allocated from the OpenMoko USB vendor space and is visible as 'USBtrng' here: http://wiki.openmoko.org/wiki/USB_Product_IDs v2: Respond to review from Oliver Neukum <oneukum@suse.de> * Delete extensive debug infrastructure and replace it with calls to dev_dbg. * Allocate I/O buffer separately from device structure to obey requirements for non-coherant architectures. * Initialize mutexes before registering device to ensure that open cannot be invoked before the device is ready to proceed. * Return number of bytes read instead of -EINTR when partial read operation is aborted due to a signal. * Make sure device mutex is unlocked in read error paths. * Add MAINTAINERS entry for the driver Signed-off-by: Keith Packard <keithp@keithp.com> Cc: Oliver Neukum <oneukum@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>