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path: root/drivers/usb/usbip/stub_dev.c
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2021-03-10usbip: fix stub_dev usbip_sockfd_store() races leading to gpfShuah Khan
usbip_sockfd_store() is invoked when user requests attach (import) detach (unimport) usb device from usbip host. vhci_hcd sends import request and usbip_sockfd_store() exports the device if it is free for export. Export and unexport are governed by local state and shared state - Shared state (usbip device status, sockfd) - sockfd and Device status are used to determine if stub should be brought up or shut down. - Local state (tcp_socket, rx and tx thread task_struct ptrs) A valid tcp_socket controls rx and tx thread operations while the device is in exported state. - While the device is exported, device status is marked used and socket, sockfd, and thread pointers are valid. Export sequence (stub-up) includes validating the socket and creating receive (rx) and transmit (tx) threads to talk to the client to provide access to the exported device. rx and tx threads depends on local and shared state to be correct and in sync. Unexport (stub-down) sequence shuts the socket down and stops the rx and tx threads. Stub-down sequence relies on local and shared states to be in sync. There are races in updating the local and shared status in the current stub-up sequence resulting in crashes. These stem from starting rx and tx threads before local and global state is updated correctly to be in sync. 1. Doesn't handle kthread_create() error and saves invalid ptr in local state that drives rx and tx threads. 2. Updates tcp_socket and sockfd, starts stub_rx and stub_tx threads before updating usbip_device status to SDEV_ST_USED. This opens up a race condition between the threads and usbip_sockfd_store() stub up and down handling. Fix the above problems: - Stop using kthread_get_run() macro to create/start threads. - Create threads and get task struct reference. - Add kthread_create() failure handling and bail out. - Hold usbip_device lock to update local and shared states after creating rx and tx threads. - Update usbip_device status to SDEV_ST_USED. - Update usbip_device tcp_socket, sockfd, tcp_rx, and tcp_tx - Start threads after usbip_device (tcp_socket, sockfd, tcp_rx, tcp_tx, and status) is complete. Credit goes to syzbot and Tetsuo Handa for finding and root-causing the kthread_get_run() improper error handling problem and others. This is a hard problem to find and debug since the races aren't seen in a normal case. Fuzzing forces the race window to be small enough for the kthread_get_run() error path bug and starting threads before updating the local and shared state bug in the stub-up sequence. Tested with syzbot reproducer: - https://syzkaller.appspot.com/text?tag=ReproC&x=14801034d00000 Fixes: 9720b4bc76a83807 ("staging/usbip: convert to kthread") Cc: stable@vger.kernel.org Reported-by: syzbot <syzbot+a93fba6d384346a761e3@syzkaller.appspotmail.com> Reported-by: syzbot <syzbot+bf1a360e305ee719e364@syzkaller.appspotmail.com> Reported-by: syzbot <syzbot+95ce4b142579611ef0a9@syzkaller.appspotmail.com> Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org> Link: https://lore.kernel.org/r/268a0668144d5ff36ec7d87fdfa90faf583b7ccc.1615171203.git.skhan@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-10usbip: fix stub_dev to check for stream socketShuah Khan
Fix usbip_sockfd_store() to validate the passed in file descriptor is a stream socket. If the file descriptor passed was a SOCK_DGRAM socket, sock_recvmsg() can't detect end of stream. Cc: stable@vger.kernel.org Suggested-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org> Link: https://lore.kernel.org/r/e942d2bd03afb8e8552bd2a5d84e18d17670d521.1615171203.git.skhan@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-25Revert "usbip: Implement a match function to fix usbip"M. Vefa Bicakci
This commit reverts commit 7a2f2974f265 ("usbip: Implement a match function to fix usbip"). In summary, commit d5643d2249b2 ("USB: Fix device driver race") inadvertently broke usbip functionality, which I resolved in an incorrect manner by introducing a match function to usbip, usbip_match(), that unconditionally returns true. However, the usbip_match function, as is, causes usbip to take over virtual devices used by syzkaller for USB fuzzing, which is a regression reported by Andrey Konovalov. Furthermore, in conjunction with the fix of another bug, handled by another patch titled "usbcore/driver: Fix specific driver selection" in this patch set, the usbip_match function causes unexpected USB subsystem behaviour when the usbip_host driver is loaded. The unexpected behaviour can be qualified as follows: - If commit 41160802ab8e ("USB: Simplify USB ID table match") is included in the kernel, then all USB devices are bound to the usbip_host driver, which appears to the user as if all USB devices were disconnected. - If the same commit (41160802ab8e) is not in the kernel (as is the case with v5.8.10) then all USB devices are re-probed and re-bound to their original device drivers, which appears to the user as a disconnection and re-connection of USB devices. Please note that this commit will make usbip non-operational again, until yet another patch in this patch set is merged, titled "usbcore/driver: Accommodate usbip". Cc: <stable@vger.kernel.org> # 5.8: 41160802ab8e: USB: Simplify USB ID table match Cc: <stable@vger.kernel.org> # 5.8 Cc: Bastien Nocera <hadess@hadess.net> Cc: Valentina Manea <valentina.manea.m@gmail.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: <syzkaller@googlegroups.com> Reported-by: Andrey Konovalov <andreyknvl@google.com> Tested-by: Andrey Konovalov <andreyknvl@google.com> Acked-by: Shuah Khan <skhan@linuxfoundation.org> Signed-off-by: M. Vefa Bicakci <m.v.b@runbox.com> Link: https://lore.kernel.org/r/20200922110703.720960-2-m.v.b@runbox.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-18usbip: Implement a match function to fix usbipM. Vefa Bicakci
Commit 88b7381a939d ("USB: Select better matching USB drivers when available") introduced the use of a "match" function to select a non-generic/better driver for a particular USB device. This unfortunately breaks the operation of usbip in general, as reported in the kernel bugzilla with bug 208267 (linked below). Upon inspecting the aforementioned commit, one can observe that the original code in the usb_device_match function used to return 1 unconditionally, but the aforementioned commit makes the usb_device_match function use identifier tables and "match" virtual functions, if either of them are available. Hence, this commit implements a match function for usbip that unconditionally returns true to ensure that usbip is functional again. This change has been verified to restore usbip functionality, with a v5.7.y kernel on an up-to-date version of Qubes OS 4.0, which uses usbip to redirect USB devices between VMs. Thanks to Jonathan Dieter for the effort in bisecting this issue down to the aforementioned commit. Fixes: 88b7381a939d ("USB: Select better matching USB drivers when available") Link: https://bugzilla.kernel.org/show_bug.cgi?id=208267 Link: https://bugzilla.redhat.com/show_bug.cgi?id=1856443 Link: https://github.com/QubesOS/qubes-issues/issues/5905 Signed-off-by: M. Vefa Bicakci <m.v.b@runbox.com> Cc: <stable@vger.kernel.org> # 5.7 Cc: Valentina Manea <valentina.manea.m@gmail.com> Cc: Alan Stern <stern@rowland.harvard.edu> Reviewed-by: Bastien Nocera <hadess@hadess.net> Reviewed-by: Shuah Khan <skhan@linuxfoundation.org> Link: https://lore.kernel.org/r/20200810160017.46002-1-m.v.b@runbox.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-08-09USB: usbip: convert to use dev_groupsGreg Kroah-Hartman
USB drivers now support the ability for the driver core to handle the creation and removal of device-specific sysfs files in a race-free manner. Take advantage of that by converting the driver to use this by moving the sysfs attributes into a group and assigning the dev_groups pointer to it. Cc: Valentina Manea <valentina.manea.m@gmail.com> Cc: Shuah Khan <shuah@kernel.org> Link: https://lore.kernel.org/r/20190806144502.17792-13-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-29usbip: usbip_host: fix stub_dev lock context imbalance regressionShuah Khan
Fix the following sparse context imbalance regression introduced in a patch that fixed sleeping function called from invalid context bug. kbuild test robot reported on: tree/branch: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-linus Regressions in current branch: drivers/usb/usbip/stub_dev.c:399:9: sparse: sparse: context imbalance in 'stub_probe' - different lock contexts for basic block drivers/usb/usbip/stub_dev.c:418:13: sparse: sparse: context imbalance in 'stub_disconnect' - different lock contexts for basic block drivers/usb/usbip/stub_dev.c:464:1-10: second lock on line 476 Error ids grouped by kconfigs: recent_errors ├── i386-allmodconfig │ └── drivers-usb-usbip-stub_dev.c:second-lock-on-line ├── x86_64-allmodconfig │ ├── drivers-usb-usbip-stub_dev.c:sparse:sparse:context-imbalance-in-stub_disconnect-different-lock-contexts-for-basic-block │ └── drivers-usb-usbip-stub_dev.c:sparse:sparse:context-imbalance-in-stub_probe-different-lock-contexts-for-basic-block └── x86_64-allyesconfig └── drivers-usb-usbip-stub_dev.c:second-lock-on-line This is a real problem in an error leg where spin_lock() is called on an already held lock. Fix the imbalance in stub_probe() and stub_disconnect(). Signed-off-by: Shuah Khan <skhan@linuxfoundation.org> Fixes: 0c9e8b3cad65 ("usbip: usbip_host: fix BUG: sleeping function called from invalid context") Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21usbip: usbip_host: fix BUG: sleeping function called from invalid contextShuah Khan
stub_probe() and stub_disconnect() call functions which could call sleeping function in invalid context whil holding busid_lock. Fix the problem by refining the lock holds to short critical sections to change the busid_priv fields. This fix restructures the code to limit the lock holds in stub_probe() and stub_disconnect(). stub_probe(): [15217.927028] BUG: sleeping function called from invalid context at mm/slab.h:418 [15217.927038] in_atomic(): 1, irqs_disabled(): 0, pid: 29087, name: usbip [15217.927044] 5 locks held by usbip/29087: [15217.927047] #0: 0000000091647f28 (sb_writers#6){....}, at: vfs_write+0x191/0x1c0 [15217.927062] #1: 000000008f9ba75b (&of->mutex){....}, at: kernfs_fop_write+0xf7/0x1b0 [15217.927072] #2: 00000000872e5b4b (&dev->mutex){....}, at: __device_driver_lock+0x3b/0x50 [15217.927082] #3: 00000000e74ececc (&dev->mutex){....}, at: __device_driver_lock+0x46/0x50 [15217.927090] #4: 00000000b20abbe0 (&(&busid_table[i].busid_lock)->rlock){....}, at: get_busid_priv+0x48/0x60 [usbip_host] [15217.927103] CPU: 3 PID: 29087 Comm: usbip Tainted: G W 5.1.0-rc6+ #40 [15217.927106] Hardware name: Dell Inc. OptiPlex 790/0HY9JP, BIOS A18 09/24/2013 [15217.927109] Call Trace: [15217.927118] dump_stack+0x63/0x85 [15217.927127] ___might_sleep+0xff/0x120 [15217.927133] __might_sleep+0x4a/0x80 [15217.927143] kmem_cache_alloc_trace+0x1aa/0x210 [15217.927156] stub_probe+0xe8/0x440 [usbip_host] [15217.927171] usb_probe_device+0x34/0x70 stub_disconnect(): [15279.182478] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:908 [15279.182487] in_atomic(): 1, irqs_disabled(): 0, pid: 29114, name: usbip [15279.182492] 5 locks held by usbip/29114: [15279.182494] #0: 0000000091647f28 (sb_writers#6){....}, at: vfs_write+0x191/0x1c0 [15279.182506] #1: 00000000702cf0f3 (&of->mutex){....}, at: kernfs_fop_write+0xf7/0x1b0 [15279.182514] #2: 00000000872e5b4b (&dev->mutex){....}, at: __device_driver_lock+0x3b/0x50 [15279.182522] #3: 00000000e74ececc (&dev->mutex){....}, at: __device_driver_lock+0x46/0x50 [15279.182529] #4: 00000000b20abbe0 (&(&busid_table[i].busid_lock)->rlock){....}, at: get_busid_priv+0x48/0x60 [usbip_host] [15279.182541] CPU: 0 PID: 29114 Comm: usbip Tainted: G W 5.1.0-rc6+ #40 [15279.182543] Hardware name: Dell Inc. OptiPlex 790/0HY9JP, BIOS A18 09/24/2013 [15279.182546] Call Trace: [15279.182554] dump_stack+0x63/0x85 [15279.182561] ___might_sleep+0xff/0x120 [15279.182566] __might_sleep+0x4a/0x80 [15279.182574] __mutex_lock+0x55/0x950 [15279.182582] ? get_busid_priv+0x48/0x60 [usbip_host] [15279.182587] ? reacquire_held_locks+0xec/0x1a0 [15279.182591] ? get_busid_priv+0x48/0x60 [usbip_host] [15279.182597] ? find_held_lock+0x94/0xa0 [15279.182609] mutex_lock_nested+0x1b/0x20 [15279.182614] ? mutex_lock_nested+0x1b/0x20 [15279.182618] kernfs_remove_by_name_ns+0x2a/0x90 [15279.182625] sysfs_remove_file_ns+0x15/0x20 [15279.182629] device_remove_file+0x19/0x20 [15279.182634] stub_disconnect+0x6d/0x180 [usbip_host] [15279.182643] usb_unbind_device+0x27/0x60 Signed-off-by: Shuah Khan <skhan@linuxfoundation.org> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-15usbip: usbip_host: fix NULL-ptr deref and use-after-free errorsShuah Khan (Samsung OSG)
usbip_host updates device status without holding lock from stub probe, disconnect and rebind code paths. When multiple requests to import a device are received, these unprotected code paths step all over each other and drive fails with NULL-ptr deref and use-after-free errors. The driver uses a table lock to protect the busid array for adding and deleting busids to the table. However, the probe, disconnect and rebind paths get the busid table entry and update the status without holding the busid table lock. Add a new finer grain lock to protect the busid entry. This new lock will be held to search and update the busid entry fields from get_busid_idx(), add_match_busid() and del_match_busid(). match_busid_show() does the same to access the busid entry fields. get_busid_priv() changed to return the pointer to the busid entry holding the busid lock. stub_probe(), stub_disconnect() and stub_device_rebind() call put_busid_priv() to release the busid lock before returning. This changes fixes the unprotected code paths eliminating the race conditions in updating the busid entries. Reported-by: Jakub Jirasek Signed-off-by: Shuah Khan (Samsung OSG) <shuah@kernel.org> Cc: stable <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-15usbip: usbip_host: run rebind from exit when module is removedShuah Khan (Samsung OSG)
After removing usbip_host module, devices it releases are left without a driver. For example, when a keyboard or a mass storage device are bound to usbip_host when it is removed, these devices are no longer bound to any driver. Fix it to run device_attach() from the module exit routine to restore the devices to their original drivers. This includes cleanup changes and moving device_attach() code to a common routine to be called from rebind_store() and usbip_host_exit(). Signed-off-by: Shuah Khan (Samsung OSG) <shuah@kernel.org> Cc: stable <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-15usbip: usbip_host: refine probe and disconnect debug msgs to be usefulShuah Khan
Refine probe and disconnect debug msgs to be useful and say what is in progress. Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com> Cc: stable <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-15usbip: keep usbip_device sockfd state in sync with tcp_socketShuah Khan
Keep usbip_device sockfd state in sync with tcp_socket. When tcp_socket is reset to null, reset sockfd to -1 to keep it in sync. Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com> Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-24USB: move many drivers to use DEVICE_ATTR_WOGreg Kroah-Hartman
Instead of "open coding" a DEVICE_ATTR() define, use the DEVICE_ATTR_WO() macro instead, which does everything properly instead. This does require a few static functions to be renamed to work properly, but thanks to a script from Joe Perches, this was easily done. Reported-by: Joe Perches <joe@perches.com> Cc: Peter Chen <Peter.Chen@nxp.com> Cc: Valentina Manea <valentina.manea.m@gmail.com> Acked-by: Felipe Balbi <felipe.balbi@linux.intel.com> Acked-by: Johan Hovold <johan@kernel.org> Acked-by: Shuah Khan <shuahkh@osg.samsung.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-19usbip: prevent leaking socket pointer address in messagesShuah Khan
usbip driver is leaking socket pointer address in messages. Remove the messages that aren't useful and print sockfd in the ones that are useful for debugging. Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-07USB: usbip: Remove redundant license textGreg Kroah-Hartman
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: Valentina Manea <valentina.manea.m@gmail.com> Acked-by: Shuah Khan <shuahkh@osg.samsung.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-Hartman
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>
2016-04-28usbip: fix NULL pointer dereference on errorsAlexander Popov
Fix NULL pointer dereference and obsolete comments forgotten when usbip server was converted from an interface driver to a device driver. Signed-off-by: Alexander Popov <alpopov@ptsecurity.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-19usbip: event handler as one threadNobuo Iwata
Dear all, 1. Overview In current USB/IP implementation, event kernel threads are created for each port. The functions of the threads are closing connection and error handling so they don't have not so many events to handle. There's no need to have thread for each port. BEFORE) vhci side - VHCI_NPORTS(8) threads are created. $ ps aux | grep usbip root 10059 0.0 0.0 0 0 ? S 17:06 0:00 [usbip_eh] root 10060 0.0 0.0 0 0 ? S 17:06 0:00 [usbip_eh] root 10061 0.0 0.0 0 0 ? S 17:06 0:00 [usbip_eh] root 10062 0.0 0.0 0 0 ? S 17:06 0:00 [usbip_eh] root 10063 0.0 0.0 0 0 ? S 17:06 0:00 [usbip_eh] root 10064 0.0 0.0 0 0 ? S 17:06 0:00 [usbip_eh] root 10065 0.0 0.0 0 0 ? S 17:06 0:00 [usbip_eh] root 10066 0.0 0.0 0 0 ? S 17:06 0:00 [usbip_eh] BEFORE) stub side - threads will be created every bind operation. $ ps aux | grep usbip root 8368 0.0 0.0 0 0 ? S 17:56 0:00 [usbip_eh] root 8399 0.0 0.0 0 0 ? S 17:56 0:00 [usbip_eh] This patch put event threads of stub and vhci driver as one workqueue. AFTER) only one event threads in each vhci and stub side. $ ps aux | grep usbip root 10457 0.0 0.0 0 0 ? S< 17:47 0:00 [usbip_event] 2. Modification to usbip_event.c BEFORE) kernel threads are created in usbip_start_eh(). AFTER) one workqueue is created in new usbip_init_eh(). Event handler which was main loop of kernel thread is modified to workqueue handler. Events themselves are stored in struct usbip_device - same as before. usbip_devices which have event are listed in event_list. The handler picks an element from the list and wakeup usbip_device. The wakeup method is same as before. usbip_in_eh() substitutes statement which checks whether functions are called from eh_ops or not. In this function, the worker context is used for the checking. The context will be set in a variable in the beginning of first event handling. usbip_in_eh() is used in event handler so it works well. 3. Modifications to programs using usbip_event.c Initialization and termination of workqueue are added to init and exit routine of usbip_core respectively. A. version info v2) # Merged 1/2 event handler itself and 2/2 user programs because of auto build fail at 1/2 casued unmodified user programs in 1/2. Signed-off-by: Nobuo Iwata <nobuo.iwata@fujixerox.co.jp> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-12-02usbip: fix error handling in stub_probe()Alexey Khoroshilov
If usb_hub_claim_port() fails, no resources are deallocated and if stub_add_files() fails, port is not released. The patch fixes these issues and rearranges error handling code. Found by Linux Driver Verification project (linuxtesting.org). Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru> Acked-by: Valentina Manea <valentina.manea.m@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-08-25usbip: remove struct usb_device_id tableValentina Manea
This was used back when usbip-host was an interface device driver; after the conversion to device driver, the table remained unused. Remove it in order to stop receiving a warning about it. Signed-off-by: Valentina Manea <valentina.manea.m@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-08-25usbip: move usbip kernel code out of stagingValentina Manea
At this point, USB/IP kernel code is fully functional and can be moved out of staging. Signed-off-by: Valentina Manea <valentina.manea.m@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>