[REJECTED CVE] The Xen netfront driver in the Linux kernel was vulnerable to attacks via an excessive number of events sent by the backend, leading to event channel storms.

[REJECTED CVE] The Xen blkfront driver in the Linux kernel was vulnerable to attacks via excessive event channels sent by the backend. This could lead to event channel storms.

In the Linux kernel, the following vulnerability has been resolved: net: nexthop: fix null pointer dereference when IPv6 is not enabled When we try to add an IPv6 nexthop and IPv6 is not enabled (!CONFIG_IPV6) we'll hit a NULL pointer dereference[1] in the error path of nh_create_ipv6() due to calling ipv6_stub->fib6_nh_release. The bug has been present since the beginning of IPv6 nexthop gateway support. Commit 1aefd3de7bc6 ("ipv6: Add fib6_nh_init and release to stubs") tells us that only fib6_nh_init has a dummy stub because fib6_nh_release should not be called if fib6_nh_init returns an error, but the commit below added a call to ipv6_stub->fib6_nh_release in its error path. To fix it return the dummy stub's -EAFNOSUPPORT error directly without calling ipv6_stub->fib6_nh_release in nh_create_ipv6()'s error path. [1] Output is a bit truncated, but it clearly shows the error. BUG: kernel NULL pointer dereference, address: 000000000000000000 #PF: supervisor instruction fetch in ker...

In the Linux kernel, the following vulnerability has been resolved: staging: rtl8192e: Fix use after free in _rtl92e_pci_disconnect() The free_rtllib() function frees the "dev" pointer so there is use after free on the next line. Re-arrange things to avoid that.

In the Linux kernel, the following vulnerability has been resolved: staging: r8188eu: fix a memory leak in rtw_wx_read32() Free "ptmp" before returning -EINVAL.

In the Linux kernel, the following vulnerability has been resolved: io_uring: fail cancellation for EXITING tasks WARNING: CPU: 1 PID: 20 at fs/io_uring.c:6269 io_try_cancel_userdata+0x3c5/0x640 fs/io_uring.c:6269 CPU: 1 PID: 20 Comm: kworker/1:0 Not tainted 5.16.0-rc1-syzkaller #0 Workqueue: events io_fallback_req_func RIP: 0010:io_try_cancel_userdata+0x3c5/0x640 fs/io_uring.c:6269 Call Trace: <TASK> io_req_task_link_timeout+0x6b/0x1e0 fs/io_uring.c:6886 io_fallback_req_func+0xf9/0x1ae fs/io_uring.c:1334 process_one_work+0x9b2/0x1690 kernel/workqueue.c:2298 worker_thread+0x658/0x11f0 kernel/workqueue.c:2445 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 </TASK> We need original task's context to do cancellations, so if it's dying and the callback is executed in a fallback mode, fail the cancellation attempt.

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix memleak in get_file_stream_info() Fix memleak in get_file_stream_info()

In the Linux kernel, the following vulnerability has been resolved: powerpc/32: Fix hardlockup on vmap stack overflow Since the commit c118c7303ad5 ("powerpc/32: Fix vmap stack - Do not activate MMU before reading task struct") a vmap stack overflow results in a hard lockup. This is because emergency_ctx is still addressed with its virtual address allthough data MMU is not active anymore at that time. Fix it by using a physical address instead.

In the Linux kernel, the following vulnerability has been resolved: proc/vmcore: fix clearing user buffer by properly using clear_user() To clear a user buffer we cannot simply use memset, we have to use clear_user(). With a virtio-mem device that registers a vmcore_cb and has some logically unplugged memory inside an added Linux memory block, I can easily trigger a BUG by copying the vmcore via "cp": systemd[1]: Starting Kdump Vmcore Save Service... kdump[420]: Kdump is using the default log level(3). kdump[453]: saving to /sysroot/var/crash/127.0.0.1-2021-11-11-14:59:22/ kdump[458]: saving vmcore-dmesg.txt to /sysroot/var/crash/127.0.0.1-2021-11-11-14:59:22/ kdump[465]: saving vmcore-dmesg.txt complete kdump[467]: saving vmcore BUG: unable to handle page fault for address: 00007f2374e01000 #PF: supervisor write access in kernel mode #PF: error_code(0x0003) - permissions violation PGD 7a523067 P4D 7a523067 PUD 7a528067 PMD 7a525067 PTE 800000007048f867 Oops: 0003 [#1] PREEMPT SMP ...

In the Linux kernel, the following vulnerability has been resolved: scsi: mpt3sas: Fix kernel panic during drive powercycle test While looping over shost's sdev list it is possible that one of the drives is getting removed and its sas_target object is freed but its sdev object remains intact. Consequently, a kernel panic can occur while the driver is trying to access the sas_address field of sas_target object without also checking the sas_target object for NULL.

In the Linux kernel, the following vulnerability has been resolved: net: marvell: prestera: fix double free issue on err path fix error path handling in prestera_bridge_port_join() that cases prestera driver to crash (see below). Trace: Internal error: Oops: 96000044 [#1] SMP Modules linked in: prestera_pci prestera uio_pdrv_genirq CPU: 1 PID: 881 Comm: ip Not tainted 5.15.0 #1 pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : prestera_bridge_destroy+0x2c/0xb0 [prestera] lr : prestera_bridge_port_join+0x2cc/0x350 [prestera] sp : ffff800011a1b0f0 ... x2 : ffff000109ca6c80 x1 : dead000000000100 x0 : dead000000000122 Call trace: prestera_bridge_destroy+0x2c/0xb0 [prestera] prestera_bridge_port_join+0x2cc/0x350 [prestera] prestera_netdev_port_event.constprop.0+0x3c4/0x450 [prestera] prestera_netdev_event_handler+0xf4/0x110 [prestera] raw_notifier_call_chain+0x54/0x80 call_netdevice_notifiers_info+0x54/0xa0 __netdev_upper_dev_link+0x19c/0x380

In the Linux kernel, the following vulnerability has been resolved: ice: avoid bpf_prog refcount underflow Ice driver has the routines for managing XDP resources that are shared between ndo_bpf op and VSI rebuild flow. The latter takes place for example when user changes queue count on an interface via ethtool's set_channels(). There is an issue around the bpf_prog refcounting when VSI is being rebuilt - since ice_prepare_xdp_rings() is called with vsi->xdp_prog as an argument that is used later on by ice_vsi_assign_bpf_prog(), same bpf_prog pointers are swapped with each other. Then it is also interpreted as an 'old_prog' which in turn causes us to call bpf_prog_put on it that will decrement its refcount. Below splat can be interpreted in a way that due to zero refcount of a bpf_prog it is wiped out from the system while kernel still tries to refer to it: [ 481.069429] BUG: unable to handle page fault for address: ffffc9000640f038 [ 481.077390] #PF: supervisor read access in kern...

In the Linux kernel, the following vulnerability has been resolved: ice: fix vsi->txq_map sizing The approach of having XDP queue per CPU regardless of user's setting exposed a hidden bug that could occur in case when Rx queue count differ from Tx queue count. Currently vsi->txq_map's size is equal to the doubled vsi->alloc_txq, which is not correct due to the fact that XDP rings were previously based on the Rx queue count. Below splat can be seen when ethtool -L is used and XDP rings are configured: [ 682.875339] BUG: kernel NULL pointer dereference, address: 000000000000000f [ 682.883403] #PF: supervisor read access in kernel mode [ 682.889345] #PF: error_code(0x0000) - not-present page [ 682.895289] PGD 0 P4D 0 [ 682.898218] Oops: 0000 [#1] PREEMPT SMP PTI [ 682.903055] CPU: 42 PID: 2878 Comm: ethtool Tainted: G OE 5.15.0-rc5+ #1 [ 682.912214] Hardware name: Intel Corp. GRANTLEY/GRANTLEY, BIOS GRRFCRB1.86B.0276.D07.1605190235 05/19/2016 [ 682.923380] RIP: 00...

In the Linux kernel, the following vulnerability has been resolved: i2c: virtio: disable timeout handling If a timeout is hit, it can result is incorrect data on the I2C bus and/or memory corruptions in the guest since the device can still be operating on the buffers it was given while the guest has freed them. Here is, for example, the start of a slub_debug splat which was triggered on the next transfer after one transfer was forced to timeout by setting a breakpoint in the backend (rust-vmm/vhost-device): BUG kmalloc-1k (Not tainted): Poison overwritten First byte 0x1 instead of 0x6b Allocated in virtio_i2c_xfer+0x65/0x35c age=350 cpu=0 pid=29 __kmalloc+0xc2/0x1c9 virtio_i2c_xfer+0x65/0x35c __i2c_transfer+0x429/0x57d i2c_transfer+0x115/0x134 i2cdev_ioctl_rdwr+0x16a/0x1de i2cdev_ioctl+0x247/0x2ed vfs_ioctl+0x21/0x30 sys_ioctl+0xb18/0xb41 Freed in virtio_i2c_xfer+0x32e/0x35c age=244 cpu=0 pid=29 kfree+0x1bd/0x1cc virtio_i2c_xfer+0x32e/0x35c __i2c_transfer+0x429/0x57d i2c_transfer+0x...

In the Linux kernel, the following vulnerability has been resolved: mlxsw: spectrum: Protect driver from buggy firmware When processing port up/down events generated by the device's firmware, the driver protects itself from events reported for non-existent local ports, but not the CPU port (local port 0), which exists, but lacks a netdev. This can result in a NULL pointer dereference when calling netif_carrier_{on,off}(). Fix this by bailing early when processing an event reported for the CPU port. Problem was only observed when running on top of a buggy emulator.

In the Linux kernel, the following vulnerability has been resolved: net/smc: Fix NULL pointer dereferencing in smc_vlan_by_tcpsk() Coverity reports a possible NULL dereferencing problem: in smc_vlan_by_tcpsk(): 6. returned_null: netdev_lower_get_next returns NULL (checked 29 out of 30 times). 7. var_assigned: Assigning: ndev = NULL return value from netdev_lower_get_next. 1623 ndev = (struct net_device *)netdev_lower_get_next(ndev, &lower); CID 1468509 (#1 of 1): Dereference null return value (NULL_RETURNS) 8. dereference: Dereferencing a pointer that might be NULL ndev when calling is_vlan_dev. 1624 if (is_vlan_dev(ndev)) { Remove the manual implementation and use netdev_walk_all_lower_dev() to iterate over the lower devices. While on it remove an obsolete function parameter comment.

In the Linux kernel, the following vulnerability has been resolved: net: stmmac: Disable Tx queues when reconfiguring the interface The Tx queues were not disabled in situations where the driver needed to stop the interface to apply a new configuration. This could result in a kernel panic when doing any of the 3 following actions: * reconfiguring the number of queues (ethtool -L) * reconfiguring the size of the ring buffers (ethtool -G) * installing/removing an XDP program (ip l set dev ethX xdp) Prevent the panic by making sure netif_tx_disable is called when stopping an interface. Without this patch, the following kernel panic can be observed when doing any of the actions above: Unable to handle kernel paging request at virtual address ffff80001238d040 [....] Call trace: dwmac4_set_addr+0x8/0x10 dev_hard_start_xmit+0xe4/0x1ac sch_direct_xmit+0xe8/0x39c __dev_queue_xmit+0x3ec/0xaf0 dev_queue_xmit+0x14/0x20 [...] [ end trace 0000000000000002 ]---

In the Linux kernel, the following vulnerability has been resolved: net/sched: sch_ets: don't peek at classes beyond 'nbands' when the number of DRR classes decreases, the round-robin active list can contain elements that have already been freed in ets_qdisc_change(). As a consequence, it's possible to see a NULL dereference crash, caused by the attempt to call cl->qdisc->ops->peek(cl->qdisc) when cl->qdisc is NULL: BUG: kernel NULL pointer dereference, address: 0000000000000018 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP NOPTI CPU: 1 PID: 910 Comm: mausezahn Not tainted 5.16.0-rc1+ #475 Hardware name: Red Hat KVM, BIOS 1.11.1-4.module+el8.1.0+4066+0f1aadab 04/01/2014 RIP: 0010:ets_qdisc_dequeue+0x129/0x2c0 [sch_ets] Code: c5 01 41 39 ad e4 02 00 00 0f 87 18 ff ff ff 49 8b 85 c0 02 00 00 49 39 c4 0f 84 ba 00 00 00 49 8b ad c0 02 00 00 48 8b 7d 10 <48> 8b 47 18 48 8b 40 38 0f ae e8 ff d0 48 89 c3 48 85 ...

In the Linux kernel, the following vulnerability has been resolved: ethtool: ioctl: fix potential NULL deref in ethtool_set_coalesce() ethtool_set_coalesce() now uses both the .get_coalesce() and .set_coalesce() callbacks. But the check for their availability is buggy, so changing the coalesce settings on a device where the driver provides only _one_ of the callbacks results in a NULL pointer dereference instead of an -EOPNOTSUPP. Fix the condition so that the availability of both callbacks is ensured. This also matches the netlink code. Note that reproducing this requires some effort - it only affects the legacy ioctl path, and needs a specific combination of driver options: - have .get_coalesce() and .coalesce_supported but no .set_coalesce(), or - have .set_coalesce() but no .get_coalesce(). Here eg. ethtool doesn't cause the crash as it first attempts to call ethtool_get_coalesce() and bails out on error.

In the Linux kernel, the following vulnerability has been resolved: net: vlan: fix underflow for the real_dev refcnt Inject error before dev_hold(real_dev) in register_vlan_dev(), and execute the following testcase: ip link add dev dummy1 type dummy ip link add name dummy1.100 link dummy1 type vlan id 100 ip link del dev dummy1 When the dummy netdevice is removed, we will get a WARNING as following: ======================================================================= refcount_t: decrement hit 0; leaking memory. WARNING: CPU: 2 PID: 0 at lib/refcount.c:31 refcount_warn_saturate+0xbf/0x1e0 and an endless loop of: ======================================================================= unregister_netdevice: waiting for dummy1 to become free. Usage count = -1073741824 That is because dev_put(real_dev) in vlan_dev_free() be called without dev_hold(real_dev) in register_vlan_dev(). It makes the refcnt of real_dev underflow. Move the dev_hold(real_dev) to vlan_dev_init() which is the cal...