linux-azure vulnerabilities · Page 200

vt: Clear selection before changing the font

In the Linux kernel, the following vulnerability has been resolved: vt: Clear selection before changing the font When changing the console font with ioctl(KDFONTOP) the new font size can be bigger than the previous font. A previous selection may thus now be outside of the new screen size and thus trigger out-of-bounds accesses to graphics memory if the selection is removed in vc_do_resize(). Prevent such out-of-memory accesses by dropping the selection before the various con_font_set() console handlers are called.

• Update to 4.15.0-1159.174~16.04.1

hwmon: (gpio-fan) Fix array out of bounds access

In the Linux kernel, the following vulnerability has been resolved: hwmon: (gpio-fan) Fix array out of bounds access The driver does not check if the cooling state passed to gpio_fan_set_cur_state() exceeds the maximum cooling state as stored in fan_data->num_speeds. Since the cooling state is later used as an array index in set_fan_speed(), an array out of bounds access can occur. This can be exploited by setting the state of the thermal cooling device to arbitrary values, causing for example a kernel oops when unavailable memory is accessed this way. Example kernel oops: [ 807.987276] Unable to handle kernel paging request at virtual ad

• Update to 4.15.0-1159.174~16.04.1

wifi: mac80211: Don't finalize CSA in IBSS mode if state is disconnected

In the Linux kernel, the following vulnerability has been resolved: wifi: mac80211: Don't finalize CSA in IBSS mode if state is disconnected When we are not connected to a channel, sending channel "switch" announcement doesn't make any sense. The BSS list is empty in that case. This causes the for loop in cfg80211_get_bss() to be bypassed, so the function returns NULL (check line 1424 of net/wireless/scan.c), causing the WARN_ON() in ieee80211_ibss_csa_beacon() to get triggered (check line 500 of net/mac80211/ibss.c), which was consequently reported on the syzkaller dashboard. Thus, check if we have an existing connection before generatin

• Update to 4.15.0-1159.174~16.04.1

tty: n_gsm: add sanity check for gsm->receive in gsm_receive_buf()

In the Linux kernel, the following vulnerability has been resolved: tty: n_gsm: add sanity check for gsm->receive in gsm_receive_buf() A null pointer dereference can happen when attempting to access the "gsm->receive()" function in gsmld_receive_buf(). Currently, the code assumes that gsm->recieve is only called after MUX activation. Since the gsmld_receive_buf() function can be accessed without the need to initialize the MUX, the gsm->receive() function will not be set and a NULL pointer dereference will occur. Fix this by avoiding the call to "gsm->receive()" in case the function is not initialized by adding a sanity check. Call Trace:

binder: fix UAF of ref->proc caused by race condition

In the Linux kernel, the following vulnerability has been resolved: binder: fix UAF of ref->proc caused by race condition A transaction of type BINDER_TYPE_WEAK_HANDLE can fail to increment the reference for a node. In this case, the target proc normally releases the failed reference upon close as expected. However, if the target is dying in parallel the call will race with binder_deferred_release(), so the target could have released all of its references by now leaving the cleanup of the new failed reference unhandled. The transaction then ends and the target proc gets released making the ref->proc now a dangling pointer. Later on, ref->n

• Update to 4.15.0-1159.174~16.04.1

cifs: fix small mempool leak in SMB2_negotiate()

In the Linux kernel, the following vulnerability has been resolved: cifs: fix small mempool leak in SMB2_negotiate() In some cases of failure (dialect mismatches) in SMB2_negotiate(), after the request is sent, the checks would return -EIO when they should be rather setting rc = -EIO and jumping to neg_exit to free the response buffer from mempool.

media: mceusb: Use new usb_control_msg_*() routines

In the Linux kernel, the following vulnerability has been resolved: media: mceusb: Use new usb_control_msg_*() routines Automatic kernel fuzzing led to a WARN about invalid pipe direction in the mceusb driver: ------------[ cut here ]------------ usb 6-1: BOGUS control dir, pipe 80000380 doesn't match bRequestType 40 WARNING: CPU: 0 PID: 2465 at drivers/usb/core/urb.c:410 usb_submit_urb+0x1326/0x1820 drivers/usb/core/urb.c:410 Modules linked in: CPU: 0 PID: 2465 Comm: kworker/0:2 Not tainted 5.19.0-rc4-00208-g69cb6c6556ad #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 Workqueue: usb_hub_wq hub_e

• Update to 4.15.0-1163.178~16.04.1

USB: core: Prevent nested device-reset calls

In the Linux kernel, the following vulnerability has been resolved: USB: core: Prevent nested device-reset calls Automatic kernel fuzzing revealed a recursive locking violation in usb-storage: ============================================ WARNING: possible recursive locking detected 5.18.0 #3 Not tainted -------------------------------------------- kworker/1:3/1205 is trying to acquire lock: ffff888018638db8 (&us_interface_key[i]){+.+.}-{3:3}, at: usb_stor_pre_reset+0x35/0x40 drivers/usb/storage/usb.c:230 but task is already holding lock: ffff888018638db8 (&us_interface_key[i]){+.+.}-{3:3}, at: usb_stor_pre_reset+0x35/0x40 drivers/usb/stor

• Update to 4.15.0-1159.174~16.04.1

wifi: mac80211: Fix UAF in ieee80211_scan_rx()

In the Linux kernel, the following vulnerability has been resolved: wifi: mac80211: Fix UAF in ieee80211_scan_rx() ieee80211_scan_rx() tries to access scan_req->flags after a null check, but a UAF is observed when the scan is completed and __ieee80211_scan_completed() executes, which then calls cfg80211_scan_done() leading to the freeing of scan_req. Since scan_req is rcu_dereference()'d, prevent the racing in __ieee80211_scan_completed() by ensuring that from mac80211's POV it is no longer accessed from an RCU read critical section before we call cfg80211_scan_done().

• Update to 4.15.0-1162.177~16.04.1

drm/amd/display: Increase block_sequence array size

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Increase block_sequence array size [Why] It's possible to generate more than 50 steps in hwss_build_fast_sequence, for example with a 6-pipe asic where all pipes are in one MPC chain. This overflows the block_sequence buffer and corrupts block_sequence_steps, causing a crash. [How] Expand block_sequence to 100 items. A naive upper bound on the possible number of steps for a 6-pipe asic, ignoring the potential for steps to be mutually exclusive, is 91 with current code, therefore 100 is sufficient.

crypto: algif_hash - fix double free in hash_accept

In the Linux kernel, the following vulnerability has been resolved: crypto: algif_hash - fix double free in hash_accept If accept(2) is called on socket type algif_hash with MSG_MORE flag set and crypto_ahash_import fails, sk2 is freed. However, it is also freed in af_alg_release, leading to slab-use-after-free error.

ALSA: pcm: Fix race of buffer access at PCM OSS layer

In the Linux kernel, the following vulnerability has been resolved: ALSA: pcm: Fix race of buffer access at PCM OSS layer The PCM OSS layer tries to clear the buffer with the silence data at initialization (or reconfiguration) of a stream with the explicit call of snd_pcm_format_set_silence() with runtime->dma_area. But this may lead to a UAF because the accessed runtime->dma_area might be freed concurrently, as it's performed outside the PCM ops. For avoiding it, move the code into the PCM core and perform it inside the buffer access lock, so that it won't be changed during the operation.

scsi: target: iscsi: Fix timeout on deleted connection

In the Linux kernel, the following vulnerability has been resolved: scsi: target: iscsi: Fix timeout on deleted connection NOPIN response timer may expire on a deleted connection and crash with such logs: Did not receive response to NOPIN on CID: 0, failing connection for I_T Nexus (null),i,0x00023d000125,iqn.2017-01.com.iscsi.target,t,0x3d BUG: Kernel NULL pointer dereference on read at 0x00000000 NIP strlcpy+0x8/0xb0 LR iscsit_fill_cxn_timeout_err_stats+0x5c/0xc0 [iscsi_target_mod] Call Trace: iscsit_handle_nopin_response_timeout+0xfc/0x120 [iscsi_target_mod] call_timer_fn+0x58/0x1f0 run_timer_softirq+0x740/0x860 __do_softirq+0x16c

vhost-scsi: protect vq->log_used with vq->mutex

In the Linux kernel, the following vulnerability has been resolved: vhost-scsi: protect vq->log_used with vq->mutex The vhost-scsi completion path may access vq->log_base when vq->log_used is already set to false. vhost-thread QEMU-thread vhost_scsi_complete_cmd_work() -> vhost_add_used() -> vhost_add_used_n() if (unlikely(vq->log_used)) QEMU disables vq->log_used via VHOST_SET_VRING_ADDR. mutex_lock(&vq->mutex); vq->log_used = false now!

PCI: endpoint: pci-epf-test: Fix double free that causes kernel to oops

In the Linux kernel, the following vulnerability has been resolved: PCI: endpoint: pci-epf-test: Fix double free that causes kernel to oops Fix a kernel oops found while testing the stm32_pcie Endpoint driver with handling of PERST# deassertion: During EP initialization, pci_epf_test_alloc_space() allocates all BARs, which are further freed if epc_set_bar() fails (for instance, due to no free inbound window). However, when pci_epc_set_bar() fails, the error path: pci_epc_set_bar() -> pci_epf_free_space() does not clear the previous assignment to epf_test->reg[bar]. Then, if the host reboots, the PERST# deassertion restarts the BA

crypto: lzo - Fix compression buffer overrun

In the Linux kernel, the following vulnerability has been resolved: crypto: lzo - Fix compression buffer overrun Unlike the decompression code, the compression code in LZO never checked for output overruns. It instead assumes that the caller always provides enough buffer space, disregarding the buffer length provided by the caller. Add a safe compression interface that checks for the end of buffer before each write. Use the safe interface in crypto/lzo.

dm cache: prevent BUG_ON by blocking retries on failed device resumes

In the Linux kernel, the following vulnerability has been resolved: dm cache: prevent BUG_ON by blocking retries on failed device resumes A cache device failing to resume due to mapping errors should not be retried, as the failure leaves a partially initialized policy object. Repeating the resume operation risks triggering BUG_ON when reloading cache mappings into the incomplete policy object. Reproduce steps: 1. create a cache metadata consisting of 512 or more cache blocks, with some mappings stored in the first array block of the mapping array. Here we use cache_restore v1.0 to build the metadata. cat <<EOF >> cmeta.xml <superbl

orangefs: Do not truncate file size

In the Linux kernel, the following vulnerability has been resolved: orangefs: Do not truncate file size 'len' is used to store the result of i_size_read(), so making 'len' a size_t results in truncation to 4GiB on 32-bit systems.

virtio: break and reset virtio devices on device_shutdown()

In the Linux kernel, the following vulnerability has been resolved: virtio: break and reset virtio devices on device_shutdown() Hongyu reported a hang on kexec in a VM. QEMU reported invalid memory accesses during the hang. Invalid read at addr 0x102877002, size 2, region '(null)', reason: rejected Invalid write at addr 0x102877A44, size 2, region '(null)', reason: rejected ... It was traced down to virtio-console. Kexec works fine if virtio-console is not in use. The issue is that virtio-console continues to write to the MMIO even after underlying virtio-pci device is reset. Additionally, Eric noticed that IOMMUs are reset before de

dm: fix unconditional IO throttle caused by REQ_PREFLUSH

In the Linux kernel, the following vulnerability has been resolved: dm: fix unconditional IO throttle caused by REQ_PREFLUSH When a bio with REQ_PREFLUSH is submitted to dm, __send_empty_flush() generates a flush_bio with REQ_OP_WRITE | REQ_PREFLUSH | REQ_SYNC, which causes the flush_bio to be throttled by wbt_wait(). An example from v5.4, similar problem also exists in upstream: crash> bt 2091206 PID: 2091206 TASK: ffff2050df92a300 CPU: 109 COMMAND: "kworker/u260:0" #0 [ffff800084a2f7f0] __switch_to at ffff80004008aeb8 #1 [ffff800084a2f820] __schedule at ffff800040bfa0c4 #2 [ffff800084a2f880] schedule at ffff800