Vulnerabilities

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> ALSA: usb-audio: Check endpoint numbers at parsing Scarlett2 mixer interfaces<br /> <br /> The Scarlett2 mixer quirk in USB-audio driver may hit a NULL<br /> dereference when a malformed USB descriptor is passed, since it<br /> assumes the presence of an endpoint in the parsed interface in<br /> scarlett2_find_fc_interface(), as reported by fuzzer.<br /> <br /> For avoiding the NULL dereference, just add the sanity check of<br /> bNumEndpoints and skip the invalid interface.

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> usb: xhci: Fix memory leak in xhci_disable_slot()<br /> <br /> xhci_alloc_command() allocates a command structure and, when the<br /> second argument is true, also allocates a completion structure.<br /> Currently, the error handling path in xhci_disable_slot() only frees<br /> the command structure using kfree(), causing the completion structure<br /> to leak.<br /> <br /> Use xhci_free_command() instead of kfree(). xhci_free_command() correctly<br /> frees both the command structure and the associated completion structure.<br /> Since the command structure is allocated with zero-initialization,<br /> command-&gt;in_ctx is NULL and will not be erroneously freed by<br /> xhci_free_command().<br /> <br /> This bug was found using an experimental static analysis tool we are<br /> developing. The tool is based on the LLVM framework and is specifically<br /> designed to detect memory management issues. It is currently under<br /> active development and not yet publicly available, but we plan to<br /> open-source it after our research is published.<br /> <br /> The bug was originally detected on v6.13-rc1 using our static analysis<br /> tool, and we have verified that the issue persists in the latest mainline<br /> kernel.<br /> <br /> We performed build testing on x86_64 with allyesconfig using GCC=11.4.0.<br /> Since triggering these error paths in xhci_disable_slot() requires specific<br /> hardware conditions or abnormal state, we were unable to construct a test<br /> case to reliably trigger these specific error paths at runtime.

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> xhci: Fix NULL pointer dereference when reading portli debugfs files<br /> <br /> Michal reported and debgged a NULL pointer dereference bug in the<br /> recently added portli debugfs files<br /> <br /> Oops is caused when there are more port registers counted in<br /> xhci-&gt;max_ports than ports reported by Supported Protocol capabilities.<br /> This is possible if max_ports is more than maximum port number, or<br /> if there are gaps between ports of different speeds the &amp;#39;Supported<br /> Protocol&amp;#39; capabilities.<br /> <br /> In such cases port-&gt;rhub will be NULL so we can&amp;#39;t reach xhci behind it.<br /> Add an explicit NULL check for this case, and print portli in hex<br /> without dereferencing port-&gt;rhub.

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> usb: yurex: fix race in probe<br /> <br /> The bbu member of the descriptor must be set to the value<br /> standing for uninitialized values before the URB whose<br /> completion handler sets bbu is submitted. Otherwise there is<br /> a window during which probing can overwrite already retrieved<br /> data.

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> USB: usbtmc: Use usb_bulk_msg_killable() with user-specified timeouts<br /> <br /> The usbtmc driver accepts timeout values specified by the user in an<br /> ioctl command, and uses these timeouts for some usb_bulk_msg() calls.<br /> Since the user can specify arbitrarily long timeouts and<br /> usb_bulk_msg() uses unkillable waits, call usb_bulk_msg_killable()<br /> instead to avoid the possibility of the user hanging a kernel thread<br /> indefinitely.

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> ceph: fix i_nlink underrun during async unlink<br /> <br /> During async unlink, we drop the `i_nlink` counter before we receive<br /> the completion (that will eventually update the `i_nlink`) because "we<br /> assume that the unlink will succeed". That is not a bad idea, but it<br /> races against deletions by other clients (or against the completion of<br /> our own unlink) and can lead to an underrun which emits a WARNING like<br /> this one:<br /> <br /> WARNING: CPU: 85 PID: 25093 at fs/inode.c:407 drop_nlink+0x50/0x68<br /> Modules linked in:<br /> CPU: 85 UID: 3221252029 PID: 25093 Comm: php-cgi8.1 Not tainted 6.14.11-cm4all1-ampere #655<br /> Hardware name: Supermicro ARS-110M-NR/R12SPD-A, BIOS 1.1b 10/17/2023<br /> pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)<br /> pc : drop_nlink+0x50/0x68<br /> lr : ceph_unlink+0x6c4/0x720<br /> sp : ffff80012173bc90<br /> x29: ffff80012173bc90 x28: ffff086d0a45aaf8 x27: ffff0871d0eb5680<br /> x26: ffff087f2a64a718 x25: 0000020000000180 x24: 0000000061c88647<br /> x23: 0000000000000002 x22: ffff07ff9236d800 x21: 0000000000001203<br /> x20: ffff07ff9237b000 x19: ffff088b8296afc0 x18: 00000000f3c93365<br /> x17: 0000000000070000 x16: ffff08faffcbdfe8 x15: ffff08faffcbdfec<br /> x14: 0000000000000000 x13: 45445f65645f3037 x12: 34385f6369706f74<br /> x11: 0000a2653104bb20 x10: ffffd85f26d73290 x9 : ffffd85f25664f94<br /> x8 : 00000000000000c0 x7 : 0000000000000000 x6 : 0000000000000002<br /> x5 : 0000000000000081 x4 : 0000000000000481 x3 : 0000000000000000<br /> x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff08727d3f91e8<br /> Call trace:<br /> drop_nlink+0x50/0x68 (P)<br /> vfs_unlink+0xb0/0x2e8<br /> do_unlinkat+0x204/0x288<br /> __arm64_sys_unlinkat+0x3c/0x80<br /> invoke_syscall.constprop.0+0x54/0xe8<br /> do_el0_svc+0xa4/0xc8<br /> el0_svc+0x18/0x58<br /> el0t_64_sync_handler+0x104/0x130<br /> el0t_64_sync+0x154/0x158<br /> <br /> In ceph_unlink(), a call to ceph_mdsc_submit_request() submits the<br /> CEPH_MDS_OP_UNLINK to the MDS, but does not wait for completion.<br /> <br /> Meanwhile, between this call and the following drop_nlink() call, a<br /> worker thread may process a CEPH_CAP_OP_IMPORT, CEPH_CAP_OP_GRANT or<br /> just a CEPH_MSG_CLIENT_REPLY (the latter of which could be our own<br /> completion). These will lead to a set_nlink() call, updating the<br /> `i_nlink` counter to the value received from the MDS. If that new<br /> `i_nlink` value happens to be zero, it is illegal to decrement it<br /> further. But that is exactly what ceph_unlink() will do then.<br /> <br /> The WARNING can be reproduced this way:<br /> <br /> 1. Force async unlink; only the async code path is affected. Having<br /> no real clue about Ceph internals, I was unable to find out why the<br /> MDS wouldn&amp;#39;t give me the "Fxr" capabilities, so I patched<br /> get_caps_for_async_unlink() to always succeed.<br /> <br /> (Note that the WARNING dump above was found on an unpatched kernel,<br /> without this kludge - this is not a theoretical bug.)<br /> <br /> 2. Add a sleep call after ceph_mdsc_submit_request() so the unlink<br /> completion gets handled by a worker thread before drop_nlink() is<br /> called. This guarantees that the `i_nlink` is already zero before<br /> drop_nlink() runs.<br /> <br /> The solution is to skip the counter decrement when it is already zero,<br /> but doing so without a lock is still racy (TOCTOU). Since<br /> ceph_fill_inode() and handle_cap_grant() both hold the<br /> `ceph_inode_info.i_ceph_lock` spinlock while set_nlink() runs, this<br /> seems like the proper lock to protect the `i_nlink` updates.<br /> <br /> I found prior art in NFS and SMB (using `inode.i_lock`) and AFS (using<br /> `afs_vnode.cb_lock`). All three have the zero check as well.

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> usb: gadget: f_ncm: Fix net_device lifecycle with device_move<br /> <br /> The network device outlived its parent gadget device during<br /> disconnection, resulting in dangling sysfs links and null pointer<br /> dereference problems.<br /> <br /> A prior attempt to solve this by removing SET_NETDEV_DEV entirely [1]<br /> was reverted due to power management ordering concerns and a NO-CARRIER<br /> regression.<br /> <br /> A subsequent attempt to defer net_device allocation to bind [2] broke<br /> 1:1 mapping between function instance and network device, making it<br /> impossible for configfs to report the resolved interface name. This<br /> results in a regression where the DHCP server fails on pmOS.<br /> <br /> Use device_move to reparent the net_device between the gadget device and<br /> /sys/devices/virtual/ across bind/unbind cycles. This preserves the<br /> network interface across USB reconnection, allowing the DHCP server to<br /> retain their binding.<br /> <br /> Introduce gether_attach_gadget()/gether_detach_gadget() helpers and use<br /> __free(detach_gadget) macro to undo attachment on bind failure. The<br /> bind_count ensures device_move executes only on the first bind.<br /> <br /> [1] https://lore.kernel.org/lkml/f2a4f9847617a0929d62025748384092e5f35cce.camel@crapouillou.net/<br /> [2] https://lore.kernel.org/linux-usb/795ea759-7eaf-4f78-81f4-01ffbf2d7961@ixit.cz/

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> usb: legacy: ncm: Fix NPE in gncm_bind<br /> <br /> Commit 56a512a9b410 ("usb: gadget: f_ncm: align net_device lifecycle<br /> with bind/unbind") deferred the allocation of the net_device. This<br /> change leads to a NULL pointer dereference in the legacy NCM driver as<br /> it attempts to access the net_device before it&amp;#39;s fully instantiated.<br /> <br /> Store the provided qmult, host_addr, and dev_addr into the struct<br /> ncm_opts-&gt;net_opts during gncm_bind(). These values will be properly<br /> applied to the net_device when it is allocated and configured later in<br /> the binding process by the NCM function driver.

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> usb: gadget: f_ncm: Fix atomic context locking issue<br /> <br /> The ncm_set_alt function was holding a mutex to protect against races<br /> with configfs, which invokes the might-sleep function inside an atomic<br /> context.<br /> <br /> Remove the struct net_device pointer from the f_ncm_opts structure to<br /> eliminate the contention. The connection state is now managed by a new<br /> boolean flag to preserve the use-after-free fix from<br /> commit 6334b8e4553c ("usb: gadget: f_ncm: Fix UAF ncm object at re-bind<br /> after usb ep transport error").<br /> <br /> BUG: sleeping function called from invalid context<br /> Call Trace:<br /> dump_stack_lvl+0x83/0xc0<br /> dump_stack+0x14/0x16<br /> __might_resched+0x389/0x4c0<br /> __might_sleep+0x8e/0x100<br /> ...<br /> __mutex_lock+0x6f/0x1740<br /> ...<br /> ncm_set_alt+0x209/0xa40<br /> set_config+0x6b6/0xb40<br /> composite_setup+0x734/0x2b40<br /> ...

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> USB: core: Limit the length of unkillable synchronous timeouts<br /> <br /> The usb_control_msg(), usb_bulk_msg(), and usb_interrupt_msg() APIs in<br /> usbcore allow unlimited timeout durations. And since they use<br /> uninterruptible waits, this leaves open the possibility of hanging a<br /> task for an indefinitely long time, with no way to kill it short of<br /> unplugging the target device.<br /> <br /> To prevent this sort of problem, enforce a maximum limit on the length<br /> of these unkillable timeouts. The limit chosen here, somewhat<br /> arbitrarily, is 60 seconds. On many systems (although not all) this<br /> is short enough to avoid triggering the kernel&amp;#39;s hung-task detector.<br /> <br /> In addition, clear up the ambiguity of negative timeout values by<br /> treating them the same as 0, i.e., using the maximum allowed timeout.

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> usb: class: cdc-wdm: fix reordering issue in read code path<br /> <br /> Quoting the bug report:<br /> <br /> Due to compiler optimization or CPU out-of-order execution, the<br /> desc-&gt;length update can be reordered before the memmove. If this<br /> happens, wdm_read() can see the new length and call copy_to_user() on<br /> uninitialized memory. This also violates LKMM data race rules [1].<br /> <br /> Fix it by using WRITE_ONCE and memory barriers.

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> usb: renesas_usbhs: fix use-after-free in ISR during device removal<br /> <br /> In usbhs_remove(), the driver frees resources (including the pipe array)<br /> while the interrupt handler (usbhs_interrupt) is still registered. If an<br /> interrupt fires after usbhs_pipe_remove() but before the driver is fully<br /> unbound, the ISR may access freed memory, causing a use-after-free.<br /> <br /> Fix this by calling devm_free_irq() before freeing resources. This ensures<br /> the interrupt handler is both disabled and synchronized (waits for any<br /> running ISR to complete) before usbhs_pipe_remove() is called.