kernel/linux.git/drivers/usb/usbip, branch linux-4.4.y

usbip: fix stub_dev usbip_sockfd_store() races leading to gpf

2021-03-17T15:07:21+00:00

commit 9380afd6df70e24eacbdbde33afc6a3950965d22 upstream. 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 Reported-by: syzbot Reported-by: syzbot Reported-by: Tetsuo Handa Signed-off-by: Shuah Khan Link: https://lore.kernel.org/r/268a0668144d5ff36ec7d87fdfa90faf583b7ccc.1615171203.git.skhan@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman

usbip: fix vhci_hcd to check for stream socket

2021-03-17T15:07:21+00:00

commit f55a0571690c4aae03180e001522538c0927432f upstream. Fix attach_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 Signed-off-by: Shuah Khan Link: https://lore.kernel.org/r/52712aa308915bda02cece1589e04ee8b401d1f3.1615171203.git.skhan@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman

usbip: fix stub_dev to check for stream socket

2021-03-17T15:07:21+00:00

commit 47ccc8fc2c9c94558b27b6f9e2582df32d29e6e8 upstream. 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 Signed-off-by: Shuah Khan Link: https://lore.kernel.org/r/e942d2bd03afb8e8552bd2a5d84e18d17670d521.1615171203.git.skhan@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman

usbip: Fix error path of vhci_recv_ret_submit()

2020-01-04T12:34:22+00:00

commit aabb5b833872524eaf28f52187e5987984982264 upstream. If a transaction error happens in vhci_recv_ret_submit(), event handler closes connection and changes port status to kick hub_event. Then hub tries to flush the endpoint URBs, but that causes infinite loop between usb_hub_flush_endpoint() and vhci_urb_dequeue() because "vhci_priv" in vhci_urb_dequeue() was already released by vhci_recv_ret_submit() before a transmission error occurred. Thus, vhci_urb_dequeue() terminates early and usb_hub_flush_endpoint() continuously calls vhci_urb_dequeue(). The root cause of this issue is that vhci_recv_ret_submit() terminates early without giving back URB when transaction error occurs in vhci_recv_ret_submit(). That causes the error URB to still be linked at endpoint list without “vhci_priv". So, in the case of transaction error in vhci_recv_ret_submit(), unlink URB from the endpoint, insert proper error code in urb->status and give back URB. Reported-by: Marek Marczykowski-Górecki Tested-by: Marek Marczykowski-Górecki Signed-off-by: Suwan Kim Cc: stable Acked-by: Shuah Khan Link: https://lore.kernel.org/r/20191213023055.19933-3-suwan.kim027@gmail.com Signed-off-by: Greg Kroah-Hartman

drivers: usb: usbip: Add missing break statement to switch

2019-11-12T18:13:24+00:00

commit 7c92e5fbf4dac0dd4dd41a0383adc54f16f403e2 upstream. Add missing break statement to prevent the code for case USB_PORT_FEAT_C_RESET falling through to the default case. Addresses-Coverity-ID: 143155 Signed-off-by: Gustavo A. R. Silva Signed-off-by: Greg Kroah-Hartman

usb: usbip: fix isoc packet num validation in get_pipe

2019-05-16T17:45:02+00:00

commit c409ca3be3c6ff3a1eeb303b191184e80d412862 upstream. Backport of the upstream commit, which fixed c6688ef9f297. c6688ef9f297 got backported as commit b6f826ba10dc, as the unavailable function usb_endpoint_maxp_mult had to be replaced. The upstream commit removed the call to this function, so the backport is straightforward. Original commit message: Change the validation of number_of_packets in get_pipe to compare the number of packets to a fixed maximum number of packets allowed, set to be 1024. This number was chosen due to it being used by other drivers as well, for example drivers/usb/host/uhci-q.c Background/reason: The get_pipe function in stub_rx.c validates the number of packets in isochronous mode and aborts with an error if that number is too large, in order to prevent malicious input from possibly triggering large memory allocations. This was previously done by checking whether pdu->u.cmd_submit.number_of_packets is bigger than the number of packets that would be needed for pdu->u.cmd_submit.transfer_buffer_length bytes if all except possibly the last packet had maximum length, given by usb_endpoint_maxp(epd) * usb_endpoint_maxp_mult(epd). This leads to an error if URBs with packets shorter than the maximum possible length are submitted, which is allowed according to Documentation/driver-api/usb/URB.rst and occurs for example with the snd-usb-audio driver. Fixes: b6f826ba10dc ("usbip: fix stub_rx: harden CMD_SUBMIT path to handle malicious input") Signed-off-by: Malte Leip Cc: stable # 4.4.x Signed-off-by: Sasha Levin

usbip: usbip_host: fix bad unlock balance during stub_probe()

2018-05-26T06:48:52+00:00

commit c171654caa875919be3c533d3518da8be5be966e upstream. stub_probe() calls put_busid_priv() in an error path when device isn't found in the busid_table. Fix it by making put_busid_priv() safe to be called with null struct bus_id_priv pointer. This problem happens when "usbip bind" is run without loading usbip_host driver and then running modprobe. The first failed bind attempt unbinds the device from the original driver and when usbip_host is modprobed, stub_probe() runs and doesn't find the device in its busid table and calls put_busid_priv(0 with null bus_id_priv pointer. usbip-host 3-10.2: 3-10.2 is not in match_busid table... skip! [ 367.359679] ===================================== [ 367.359681] WARNING: bad unlock balance detected! [ 367.359683] 4.17.0-rc4+ #5 Not tainted [ 367.359685] ------------------------------------- [ 367.359688] modprobe/2768 is trying to release lock ( [ 367.359689] ================================================================== [ 367.359696] BUG: KASAN: null-ptr-deref in print_unlock_imbalance_bug+0x99/0x110 [ 367.359699] Read of size 8 at addr 0000000000000058 by task modprobe/2768 [ 367.359705] CPU: 4 PID: 2768 Comm: modprobe Not tainted 4.17.0-rc4+ #5 Fixes: 22076557b07c ("usbip: usbip_host: fix NULL-ptr deref and use-after-free errors") in usb-linus Signed-off-by: Shuah Khan (Samsung OSG) Cc: stable Signed-off-by: Greg Kroah-Hartman

usbip: usbip_host: fix NULL-ptr deref and use-after-free errors

2018-05-26T06:48:52+00:00

commit 22076557b07c12086eeb16b8ce2b0b735f7a27e7 upstream. 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) Cc: stable Signed-off-by: Greg Kroah-Hartman

usbip: usbip_host: run rebind from exit when module is removed

2018-05-26T06:48:51+00:00

commit 7510df3f29d44685bab7b1918b61a8ccd57126a9 upstream. 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) Cc: stable Signed-off-by: Greg Kroah-Hartman

usbip: usbip_host: delete device from busid_table after rebind

2018-05-26T06:48:51+00:00

commit 1e180f167d4e413afccbbb4a421b48b2de832549 upstream. Device is left in the busid_table after unbind and rebind. Rebind initiates usb bus scan and the original driver claims the device. After rescan the device should be deleted from the busid_table as it no longer belongs to usbip_host. Fix it to delete the device after device_attach() succeeds. Signed-off-by: Shuah Khan (Samsung OSG) Cc: stable Signed-off-by: Greg Kroah-Hartman