kernel/linux.git/drivers/usb/misc/chaoskey.c, branch linux-7.1.y

Convert 'alloc_obj' family to use the new default GFP_KERNEL argument

2026-02-22T01:09:51+00:00

This was done entirely with mindless brute force, using git grep -l '\

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook

usb: chaoskey: fix locking for O_NONBLOCK

2025-11-21T14:10:29+00:00

A failure to take a lock with O_NONBLOCK needs to result in -EAGAIN. Change it. Fixes: 66e3e591891da ("usb: Add driver for Altus Metrum ChaosKey device (v2)") Signed-off-by: Oliver Neukum Link: https://patch.msgid.link/20251030093918.2248104-1-oneukum@suse.com Signed-off-by: Greg Kroah-Hartman

USB: chaoskey: Fix possible deadlock chaoskey_list_lock

2024-10-13T12:02:47+00:00

[Syzbot reported two possible deadlocks] The first possible deadlock is: WARNING: possible recursive locking detected 6.12.0-rc1-syzkaller-00027-g4a9fe2a8ac53 #0 Not tainted -------------------------------------------- syz-executor363/2651 is trying to acquire lock: ffffffff89b120e8 (chaoskey_list_lock){+.+.}-{3:3}, at: chaoskey_release+0x15d/0x2c0 drivers/usb/misc/chaoskey.c:322 but task is already holding lock: ffffffff89b120e8 (chaoskey_list_lock){+.+.}-{3:3}, at: chaoskey_release+0x7f/0x2c0 drivers/usb/misc/chaoskey.c:299 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(chaoskey_list_lock); lock(chaoskey_list_lock); *** DEADLOCK *** The second possible deadlock is: WARNING: possible circular locking dependency detected 6.12.0-rc1-syzkaller-00027-g4a9fe2a8ac53 #0 Not tainted ------------------------------------------------------ kworker/0:2/804 is trying to acquire lock: ffffffff899dadb0 (minor_rwsem){++++}-{3:3}, at: usb_deregister_dev+0x7c/0x1e0 drivers/usb/core/file.c:186 but task is already holding lock: ffffffff89b120e8 (chaoskey_list_lock){+.+.}-{3:3}, at: chaoskey_disconnect+0xa8/0x2a0 drivers/usb/misc/chaoskey.c:235 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (chaoskey_list_lock){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:608 [inline] __mutex_lock+0x175/0x9c0 kernel/locking/mutex.c:752 chaoskey_open+0xdd/0x220 drivers/usb/misc/chaoskey.c:274 usb_open+0x186/0x220 drivers/usb/core/file.c:47 chrdev_open+0x237/0x6a0 fs/char_dev.c:414 do_dentry_open+0x6cb/0x1390 fs/open.c:958 vfs_open+0x82/0x3f0 fs/open.c:1088 do_open fs/namei.c:3774 [inline] path_openat+0x1e6a/0x2d60 fs/namei.c:3933 do_filp_open+0x1dc/0x430 fs/namei.c:3960 do_sys_openat2+0x17a/0x1e0 fs/open.c:1415 do_sys_open fs/open.c:1430 [inline] __do_sys_openat fs/open.c:1446 [inline] __se_sys_openat fs/open.c:1441 [inline] __x64_sys_openat+0x175/0x210 fs/open.c:1441 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (minor_rwsem){++++}-{3:3}: check_prev_add kernel/locking/lockdep.c:3161 [inline] check_prevs_add kernel/locking/lockdep.c:3280 [inline] validate_chain kernel/locking/lockdep.c:3904 [inline] __lock_acquire+0x250b/0x3ce0 kernel/locking/lockdep.c:5202 lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5825 down_write+0x93/0x200 kernel/locking/rwsem.c:1577 usb_deregister_dev+0x7c/0x1e0 drivers/usb/core/file.c:186 chaoskey_disconnect+0xb7/0x2a0 drivers/usb/misc/chaoskey.c:236 usb_unbind_interface+0x1e8/0x970 drivers/usb/core/driver.c:461 device_remove drivers/base/dd.c:569 [inline] device_remove+0x122/0x170 drivers/base/dd.c:561 __device_release_driver drivers/base/dd.c:1273 [inline] device_release_driver_internal+0x44a/0x610 drivers/base/dd.c:1296 bus_remove_device+0x22f/0x420 drivers/base/bus.c:576 device_del+0x396/0x9f0 drivers/base/core.c:3864 usb_disable_device+0x36c/0x7f0 drivers/usb/core/message.c:1418 usb_disconnect+0x2e1/0x920 drivers/usb/core/hub.c:2304 hub_port_connect drivers/usb/core/hub.c:5361 [inline] hub_port_connect_change drivers/usb/core/hub.c:5661 [inline] port_event drivers/usb/core/hub.c:5821 [inline] hub_event+0x1bed/0x4f40 drivers/usb/core/hub.c:5903 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3229 process_scheduled_works kernel/workqueue.c:3310 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(chaoskey_list_lock); lock(minor_rwsem); lock(chaoskey_list_lock); lock(minor_rwsem); *** DEADLOCK *** [Analysis] The first is AA lock, it because wrong logic, it need a unlock. The second is AB lock, it needs to rearrange the order of lock usage. Fixes: 422dc0a4d12d ("USB: chaoskey: fail open after removal") Reported-by: syzbot+685e14d04fe35692d3bc@syzkaller.appspotmail.com Reported-by: syzbot+1f8ca5ee82576ec01f12@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=685e14d04fe35692d3bc Signed-off-by: Edward Adam Davis Tested-by: syzbot+685e14d04fe35692d3bc@syzkaller.appspotmail.com Reported-by: syzbot+5f1ce62e956b7b19610e@syzkaller.appspotmail.com Tested-by: syzbot+5f1ce62e956b7b19610e@syzkaller.appspotmail.com Tested-by: syzbot+1f8ca5ee82576ec01f12@syzkaller.appspotmail.com Link: https://lore.kernel.org/r/tencent_84EB865C89862EC22EE94CB3A7C706C59206@qq.com Cc: Oliver Neukum Signed-off-by: Greg Kroah-Hartman

USB: chaoskey: fail open after removal

2024-10-04T13:16:34+00:00

chaoskey_open() takes the lock only to increase the counter of openings. That means that the mutual exclusion with chaoskey_disconnect() cannot prevent an increase of the counter and chaoskey_open() returning a success. If that race is hit, chaoskey_disconnect() will happily free all resources associated with the device after it has dropped the lock, as it has read the counter as zero. To prevent this race chaoskey_open() has to check the presence of the device under the lock. However, the current per device lock cannot be used, because it is a part of the data structure to be freed. Hence an additional global mutex is needed. The issue is as old as the driver. Signed-off-by: Oliver Neukum Reported-by: syzbot+422188bce66e76020e55@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=422188bce66e76020e55 Fixes: 66e3e591891da ("usb: Add driver for Altus Metrum ChaosKey device (v2)") Rule: add Link: https://lore.kernel.org/stable/20241002132201.552578-1-oneukum%40suse.com Link: https://lore.kernel.org/r/20241002132201.552578-1-oneukum@suse.com Signed-off-by: Greg Kroah-Hartman

hwrng: core - treat default_quality as a maximum and default to 1024

2022-11-18T08:59:34+00:00

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 Cc: Ard Biesheuvel Cc: Herbert Xu Signed-off-by: Jason A. Donenfeld Signed-off-by: Herbert Xu

USB: chaoskey: fix error case of a timeout

2019-11-11T13:29:39+00:00

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 Cc: stable Link: https://lore.kernel.org/r/20191107142856.16774-1-oneukum@suse.com Signed-off-by: Greg Kroah-Hartman

USB: chaoskey: fix use-after-free on release

2019-10-10T10:43:19+00:00

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 # 4.1 Signed-off-by: Johan Hovold Link: https://lore.kernel.org/r/20191009153848.8664-3-johan@kernel.org Signed-off-by: Greg Kroah-Hartman

USB: chaoskey: Use kasprintf() over strcpy()/strcat()

2018-02-22T14:17:05+00:00

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 Reviewed-by: Keith Packard Signed-off-by: Greg Kroah-Hartman

USB: misc: chaoskey: Use true and false for boolean values

2018-01-24T07:49:51+00:00

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 Reviewed-by: Keith Packard Signed-off-by: Greg Kroah-Hartman