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path: root/drivers/char/xillybus/xillyusb.c
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2024-08-16char: xillybus: Check USB endpoints when probing deviceEli Billauer
Ensure, as the driver probes the device, that all endpoints that the driver may attempt to access exist and are of the correct type. All XillyUSB devices must have a Bulk IN and Bulk OUT endpoint at address 1. This is verified in xillyusb_setup_base_eps(). On top of that, a XillyUSB device may have additional Bulk OUT endpoints. The information about these endpoints' addresses is deduced from a data structure (the IDT) that the driver fetches from the device while probing it. These endpoints are checked in setup_channels(). A XillyUSB device never has more than one IN endpoint, as all data towards the host is multiplexed in this single Bulk IN endpoint. This is why setup_channels() only checks OUT endpoints. Reported-by: syzbot+eac39cba052f2e750dbe@syzkaller.appspotmail.com Cc: stable <stable@kernel.org> Closes: https://lore.kernel.org/all/0000000000001d44a6061f7a54ee@google.com/T/ Fixes: a53d1202aef1 ("char: xillybus: Add driver for XillyUSB (Xillybus variant for USB)"). Signed-off-by: Eli Billauer <eli.billauer@gmail.com> Link: https://lore.kernel.org/r/20240816070200.50695-2-eli.billauer@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-08-16char: xillybus: Refine workqueue handlingEli Billauer
As the wakeup work item now runs on a separate workqueue, it needs to be flushed separately along with flushing the device's workqueue. Also, move the destroy_workqueue() call to the end of the exit method, so that deinitialization is done in the opposite order of initialization. Fixes: ccbde4b128ef ("char: xillybus: Don't destroy workqueue from work item running on it") Cc: stable <stable@kernel.org> Signed-off-by: Eli Billauer <eli.billauer@gmail.com> Link: https://lore.kernel.org/r/20240816070200.50695-1-eli.billauer@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-08-13char: xillybus: Don't destroy workqueue from work item running on itEli Billauer
Triggered by a kref decrement, destroy_workqueue() may be called from within a work item for destroying its own workqueue. This illegal situation is averted by adding a module-global workqueue for exclusive use of the offending work item. Other work items continue to be queued on per-device workqueues to ensure performance. Reported-by: syzbot+91dbdfecdd3287734d8e@syzkaller.appspotmail.com Cc: stable <stable@kernel.org> Closes: https://lore.kernel.org/lkml/0000000000000ab25a061e1dfe9f@google.com/ Signed-off-by: Eli Billauer <eli.billauer@gmail.com> Link: https://lore.kernel.org/r/20240801121126.60183-1-eli.billauer@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-11char: xillybus: Prevent use-after-free due to race conditionEli Billauer
The driver for XillyUSB devices maintains a kref reference count on each xillyusb_dev structure, which represents a physical device. This reference count reaches zero when the device has been disconnected and there are no open file descriptors that are related to the device. When this occurs, kref_put() calls cleanup_dev(), which clears up the device's data, including the structure itself. However, when xillyusb_open() is called, this reference count becomes tricky: This function needs to obtain the xillyusb_dev structure that relates to the inode's major and minor (as there can be several such). xillybus_find_inode() (which is defined in xillybus_class.c) is called for this purpose. xillybus_find_inode() holds a mutex that is global in xillybus_class.c to protect the list of devices, and releases this mutex before returning. As a result, nothing protects the xillyusb_dev's reference counter from being decremented to zero before xillyusb_open() increments it on its own behalf. Hence the structure can be freed due to a rare race condition. To solve this, a mutex is added. It is locked by xillyusb_open() before the call to xillybus_find_inode() and is released only after the kref counter has been incremented on behalf of the newly opened inode. This protects the kref reference counters of all xillyusb_dev structs from being decremented by xillyusb_disconnect() during this time segment, as the call to kref_put() in this function is done with the same lock held. There is no need to hold the lock on other calls to kref_put(), because if xillybus_find_inode() finds a struct, xillyusb_disconnect() has not made the call to remove it, and hence not made its call to kref_put(), which takes place afterwards. Hence preventing xillyusb_disconnect's call to kref_put() is enough to ensure that the reference doesn't reach zero before it's incremented by xillyusb_open(). It would have been more natural to increment the reference count in xillybus_find_inode() of course, however this function is also called by Xillybus' driver for PCIe / OF, which registers a completely different structure. Therefore, xillybus_find_inode() treats these structures as void pointers, and accordingly can't make any changes. Reported-by: Hyunwoo Kim <imv4bel@gmail.com> Suggested-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Eli Billauer <eli.billauer@gmail.com> Link: https://lore.kernel.org/r/20221030094209.65916-1-eli.billauer@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-24char: xillybus: fix a refcount leak in cleanup_dev()Hangyu Hua
usb_get_dev is called in xillyusb_probe. So it is better to call usb_put_dev before xdev is released. Acked-by: Eli Billauer <eli.billauer@gmail.com> Signed-off-by: Hangyu Hua <hbh25y@gmail.com> Link: https://lore.kernel.org/r/20220406075703.23464-1-hbh25y@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-10-19char: xillybus: fix msg_ep UAF in xillyusb_probe()Ziyang Xuan
When endpoint_alloc() return failed in xillyusb_setup_base_eps(), 'xdev->msg_ep' will be freed but not set to NULL. That lets program enter fail handling to cleanup_dev() in xillyusb_probe(). Check for 'xdev->msg_ep' is invalid in cleanup_dev() because 'xdev->msg_ep' did not set to NULL when was freed. So the UAF problem for 'xdev->msg_ep' is triggered. ================================================================== BUG: KASAN: use-after-free in fifo_mem_release+0x1f4/0x210 CPU: 0 PID: 166 Comm: kworker/0:2 Not tainted 5.15.0-rc5+ #19 Call Trace: dump_stack_lvl+0xe2/0x152 print_address_description.constprop.0+0x21/0x140 ? fifo_mem_release+0x1f4/0x210 kasan_report.cold+0x7f/0x11b ? xillyusb_probe+0x530/0x700 ? fifo_mem_release+0x1f4/0x210 fifo_mem_release+0x1f4/0x210 ? __sanitizer_cov_trace_pc+0x1d/0x50 endpoint_dealloc+0x35/0x2b0 cleanup_dev+0x90/0x120 xillyusb_probe+0x59a/0x700 ... Freed by task 166: kasan_save_stack+0x1b/0x40 kasan_set_track+0x1c/0x30 kasan_set_free_info+0x20/0x30 __kasan_slab_free+0x109/0x140 kfree+0x117/0x4c0 xillyusb_probe+0x606/0x700 Set 'xdev->msg_ep' to NULL after being freed in xillyusb_setup_base_eps() to fix the UAF problem. Fixes: a53d1202aef1 ("char: xillybus: Add driver for XillyUSB (Xillybus variant for USB)") Cc: stable <stable@vger.kernel.org> Acked-by: Eli Billauer <eli.billauer@gmail.com> Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com> Link: https://lore.kernel.org/r/20211016052047.1611983-1-william.xuanziyang@huawei.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-06-03char: xillybus: Fix spelling mistake "overflew" -> "overflowed"Colin Ian King
There is a spelling mistake in a dev_err message. Fix it. Acked-by: Eli Billauer <eli.billauer@gmail.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> Link: https://lore.kernel.org/r/20210601102201.8489-1-colin.king@canonical.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-06-03char: xillybus: Remove unneeded MODULE_VERSION() usageEli Billauer
MODULE_VERSION is useless for in-kernel drivers, so these are removed from files in drivers/char/xillybus/ Reported-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Eli Billauer <eli.billauer@gmail.com> Link: https://lore.kernel.org/r/20210528092242.51104-2-eli.billauer@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-27char: xillybus: Add driver for XillyUSB (Xillybus variant for USB)Eli Billauer
The XillyUSB driver is the USB variant for the Xillybus FPGA IP core. Even though it presents a nearly identical API on the FPGA and host, it's almost a complete rewrite of the driver: The framework for exchanging data on a USB bus is fundamentally different from doing the same with a PCIe interface, which leaves very little in common between the existing driver and the new one for XillyUSB. Signed-off-by: Eli Billauer <eli.billauer@gmail.com> Link: https://lore.kernel.org/r/20210526100311.56327-3-eli.billauer@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>