CVE-2024-27004

Published May 1, 2024

Last updated 4 months ago

CVSS medium 5.5

Overview

Description
In the Linux kernel, the following vulnerability has been resolved: clk: Get runtime PM before walking tree during disable_unused Doug reported [1] the following hung task: INFO: task swapper/0:1 blocked for more than 122 seconds. Not tainted 5.15.149-21875-gf795ebc40eb8 #1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:swapper/0 state:D stack: 0 pid: 1 ppid: 0 flags:0x00000008 Call trace: __switch_to+0xf4/0x1f4 __schedule+0x418/0xb80 schedule+0x5c/0x10c rpm_resume+0xe0/0x52c rpm_resume+0x178/0x52c __pm_runtime_resume+0x58/0x98 clk_pm_runtime_get+0x30/0xb0 clk_disable_unused_subtree+0x58/0x208 clk_disable_unused_subtree+0x38/0x208 clk_disable_unused_subtree+0x38/0x208 clk_disable_unused_subtree+0x38/0x208 clk_disable_unused_subtree+0x38/0x208 clk_disable_unused+0x4c/0xe4 do_one_initcall+0xcc/0x2d8 do_initcall_level+0xa4/0x148 do_initcalls+0x5c/0x9c do_basic_setup+0x24/0x30 kernel_init_freeable+0xec/0x164 kernel_init+0x28/0x120 ret_from_fork+0x10/0x20 INFO: task kworker/u16:0:9 blocked for more than 122 seconds. Not tainted 5.15.149-21875-gf795ebc40eb8 #1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u16:0 state:D stack: 0 pid: 9 ppid: 2 flags:0x00000008 Workqueue: events_unbound deferred_probe_work_func Call trace: __switch_to+0xf4/0x1f4 __schedule+0x418/0xb80 schedule+0x5c/0x10c schedule_preempt_disabled+0x2c/0x48 __mutex_lock+0x238/0x488 __mutex_lock_slowpath+0x1c/0x28 mutex_lock+0x50/0x74 clk_prepare_lock+0x7c/0x9c clk_core_prepare_lock+0x20/0x44 clk_prepare+0x24/0x30 clk_bulk_prepare+0x40/0xb0 mdss_runtime_resume+0x54/0x1c8 pm_generic_runtime_resume+0x30/0x44 __genpd_runtime_resume+0x68/0x7c genpd_runtime_resume+0x108/0x1f4 __rpm_callback+0x84/0x144 rpm_callback+0x30/0x88 rpm_resume+0x1f4/0x52c rpm_resume+0x178/0x52c __pm_runtime_resume+0x58/0x98 __device_attach+0xe0/0x170 device_initial_probe+0x1c/0x28 bus_probe_device+0x3c/0x9c device_add+0x644/0x814 mipi_dsi_device_register_full+0xe4/0x170 devm_mipi_dsi_device_register_full+0x28/0x70 ti_sn_bridge_probe+0x1dc/0x2c0 auxiliary_bus_probe+0x4c/0x94 really_probe+0xcc/0x2c8 __driver_probe_device+0xa8/0x130 driver_probe_device+0x48/0x110 __device_attach_driver+0xa4/0xcc bus_for_each_drv+0x8c/0xd8 __device_attach+0xf8/0x170 device_initial_probe+0x1c/0x28 bus_probe_device+0x3c/0x9c deferred_probe_work_func+0x9c/0xd8 process_one_work+0x148/0x518 worker_thread+0x138/0x350 kthread+0x138/0x1e0 ret_from_fork+0x10/0x20 The first thread is walking the clk tree and calling clk_pm_runtime_get() to power on devices required to read the clk hardware via struct clk_ops::is_enabled(). This thread holds the clk prepare_lock, and is trying to runtime PM resume a device, when it finds that the device is in the process of resuming so the thread schedule()s away waiting for the device to finish resuming before continuing. The second thread is runtime PM resuming the same device, but the runtime resume callback is calling clk_prepare(), trying to grab the prepare_lock waiting on the first thread. This is a classic ABBA deadlock. To properly fix the deadlock, we must never runtime PM resume or suspend a device with the clk prepare_lock held. Actually doing that is near impossible today because the global prepare_lock would have to be dropped in the middle of the tree, the device runtime PM resumed/suspended, and then the prepare_lock grabbed again to ensure consistency of the clk tree topology. If anything changes with the clk tree in the meantime, we've lost and will need to start the operation all over again. Luckily, most of the time we're simply incrementing or decrementing the runtime PM count on an active device, so we don't have the chance to schedule away with the prepare_lock held. Let's fix this immediate problem that can be ---truncated---
Source
416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD status
Modified
Products
linux_kernel, debian_linux, fedora

Risk scores

CVSS 3.1

Type
Primary
Base score
5.5
Impact score
3.6
Exploitability score
1.8
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Severity
MEDIUM

Weaknesses

nvd@nist.gov
CWE-667

Social media

Hype score
Not currently trending

Configurations

Related CVEs

  1. A use-after-free in OpenVPN 2.6.0 through 2.6.20 and 2.7_alpha1 through 2.7.4 allows remote authenticated peers to potentially cause a denial of service or leak memory via crafted packets during TLS session promotion or expiry•CVE-2026-12996
  2. In the Linux kernel, the following vulnerability has been resolved: usb: misc: usbio: fix disconnect UAF in client teardown usbio_disconnect() walks usbio->cli_list in reverse and uninitializes each auxiliary device. auxiliary_device_uninit() drops the device reference, and for an unbound child that can run usbio_auxdev_release() and free the containing struct usbio_client. list_for_each_entry_reverse() advances after the loop body by reading client->link.prev. If the current client is freed by auxiliary_device_uninit(), the iterator dereferences freed memory. Use list_for_each_entry_safe_reverse() so the previous client is cached before the body can drop the final reference. This preserves reverse teardown order while keeping the next iterator cursor independent of the current client's lifetime. Validation reproduced this kernel report: BUG: KASAN: slab-use-after-free in usbio_disconnect+0x12e/0x150 Call Trace: <TASK> dump_stack_lvl+0x66/0xa0 print_report+0xce/0x630 ? usbio_disconnect+0x12e/0x150 ? srso_alias_return_thunk+0x5/0xfbef5 ? __virt_addr_valid+0x188/0x320 ? usbio_disconnect+0x12e/0x150 kasan_report+0xe0/0x110 ? usbio_disconnect+0x12e/0x150 usbio_disconnect+0x12e/0x150 usb_unbind_interface+0xf3/0x400 really_probe+0x316/0x660 __driver_probe_device+0x106/0x240 driver_probe_device+0x4a/0x110 __device_attach_driver+0xf1/0x1a0 ? __pfx___device_attach_driver+0x10/0x10 bus_for_each_drv+0xf9/0x160 ? __pfx_bus_for_each_drv+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 ? trace_hardirqs_on+0x18/0x130 ? srso_alias_return_thunk+0x5/0xfbef5 ? _raw_spin_unlock_irqrestore+0x44/0x60 __device_attach+0x133/0x2a0 ? __pfx___device_attach+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 ? do_raw_spin_unlock+0x9a/0x100 ? srso_alias_return_thunk+0x5/0xfbef5 device_initial_probe+0x55/0x70 bus_probe_device+0x4a/0xd0 device_add+0x9b9/0xc10 ? __pfx_device_add+0x10/0x10 ? _raw_spin_unlock_irqrestore+0x44/0x60 ? srso_alias_return_thunk+0x5/0xfbef5 ? lockdep_hardirqs_on_prepare+0xea/0x1a0 ? srso_alias_return_thunk+0x5/0xfbef5 ? usb_enable_lpm+0x3c/0x260 usb_set_configuration+0xb64/0xf20 usb_generic_driver_probe+0x5f/0x90 usb_probe_device+0x71/0x1b0 really_probe+0x46b/0x660 __driver_probe_device+0x106/0x240 driver_probe_device+0x4a/0x110 __device_attach_driver+0xf1/0x1a0 ? __pfx___device_attach_driver+0x10/0x10 bus_for_each_drv+0xf9/0x160 ? __pfx_bus_for_each_drv+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 ? trace_hardirqs_on+0x18/0x130 ? srso_alias_return_thunk+0x5/0xfbef5 ? _raw_spin_unlock_irqrestore+0x44/0x60 __device_attach+0x133/0x2a0 ? __pfx___device_attach+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 ? do_raw_spin_unlock+0x9a/0x100 ? srso_alias_return_thunk+0x5/0xfbef5 device_initial_probe+0x55/0x70 bus_probe_device+0x4a/0xd0 device_add+0x9b9/0xc10 ? __pfx_device_add+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 ? add_device_randomness+0xb7/0xf0 usb_new_device+0x492/0x870 hub_event+0x1b10/0x29c0 ? __pfx_hub_event+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 ? lock_acquire+0x187/0x300 ? process_one_work+0x475/0xb90 ? srso_alias_return_thunk+0x5/0xfbef5 ? lock_release+0xc8/0x290 ? srso_alias_return_thunk+0x5/0xfbef5 process_one_work+0x4d7/0xb90 ? __pfx_process_one_work+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 ? srso_alias_return_thunk+0x5/0xfbef5 ? __list_add_valid_or_report+0x37/0xf0 ? __pfx_hub_event+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 worker_thread+0x2d8/0x570 ? __pfx_worker_thread+0x10/0x10 kthread+0x1ad/0x1f0 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x3c9/0x540 ? __pfx_ret_from_fork+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 ? __switch_to+0x2e9/0x730 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 </TASK>•CVE-2026-64453
  3. In the Linux kernel, the following vulnerability has been resolved: 6lowpan: fix NHC entry use-after-free on error path lowpan_nhc_do_uncompression() looks up an NHC descriptor while holding lowpan_nhc_lock. If the descriptor has no uncompress callback, the error path drops the lock before printing nhc->name. lowpan_nhc_del() removes descriptors under the same lock and then relies on synchronize_net() before the owning module can be unloaded. That only waits for net RX RCU readers. lowpan_header_decompress() is also exported and can be reached from callers that are not necessarily covered by the net core RX critical section, for example the Bluetooth 6LoWPAN L2CAP receive path. This leaves a race where one task drops lowpan_nhc_lock in the error path, another task unregisters and frees the matching descriptor after synchronize_net() returns, and the first task then dereferences nhc->name for the warning. With the post-unlock window widened, KASAN reports: BUG: KASAN: slab-use-after-free in lowpan_nhc_do_uncompression+0x1f4/0x220 Read of size 8 lowpan_nhc_do_uncompression lowpan_header_decompress Fix this by printing the warning before dropping lowpan_nhc_lock, so the descriptor name is read while unregister is still excluded. The malformed packet is still rejected with -ENOTSUPP.•CVE-2026-64452
  4. In the Linux kernel, the following vulnerability has been resolved: tracing: Fix NULL pointer dereference in func_set_flag() func_set_flag() dereferences tr->current_trace_flags before verifying that the current tracer is actually the function tracer. When the active tracer has been switched away from "function" (e.g., to "wakeup_rt"), tr->current_trace_flags can be NULL, leading to a NULL pointer dereference and kernel crash. The call chain that triggers this is: trace_options_write() -> __set_tracer_option() -> trace->set_flag() /* func_set_flag */ In func_set_flag(), the first operation is: if (!!set == !!(tr->current_trace_flags->val & bit)) This dereferences tr->current_trace_flags unconditionally. The safety check that guards against a non-function tracer: if (tr->current_trace != &function_trace) return 0; is placed *after* the dereference, which is too late. This was observed with the following crash dump: BUG: unable to handle page fault at 0000000000000000 RIP: func_set_flag+0xd Call Trace: __set_tracer_option+0x27 trace_options_write+0x75 vfs_write+0x12a ksys_write+0x66 do_syscall_64+0x5b RIP: ffffffff914c973d RSP: ff67ec88b01dfdf0 RFLAGS: 00010202 RAX: 0000000000000000 RBX: ff3a826e80354580 RCX: 0000000000000001 RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffffffff93918080 The disassembly confirms the fault: func_set_flag+0: mov 0x1f08(%rdi), %rax ; RAX = tr->current_trace_flags = NULL func_set_flag+13: mov (%rax), %eax ; page fault: dereference NULL At the time of the crash: tr->current_trace_flags = 0x0 (NULL) tr->current_trace = wakeup_rt_tracer (not function_trace) The scenario is that a process opens a function tracer option file (such as "func_stack_trace"), then the current tracer is switched to another tracer (e.g., "wakeup_rt"), which sets current_trace_flags to NULL. When the process subsequently writes to the option file, func_set_flag() is invoked and crashes on the NULL dereference. Fix this by moving the current_trace check before the current_trace_flags dereference, so that func_set_flag() returns early when the function tracer is not active.•CVE-2026-64451
  5. In the Linux kernel, the following vulnerability has been resolved: tipc: fix out-of-bounds read in broadcast Gap ACK blocks A broadcast PROTOCOL/STATE_MSG can carry a Gap ACK blocks record in its data area. tipc_get_gap_ack_blks() only verifies that the record's len field is self-consistent with its ugack_cnt/bgack_cnt counts (sz == struct_size(p, gacks, ugack_cnt + bgack_cnt)); it does not check that the record actually fits in the message data area, msg_data_sz(). The unicast caller tipc_link_proto_rcv() bounds it ("if (glen > dlen) break;"), but the broadcast caller tipc_bcast_sync_rcv() discards the returned size, so tipc_link_advance_transmq() copies the record off the receive skb with an attacker-controlled count: this_ga = kmemdup(ga, struct_size(ga, gacks, ga->bgack_cnt), GFP_ATOMIC); A TIPC neighbour that negotiated TIPC_GAP_ACK_BLOCK triggers it with one ordinary broadcast STATE_MSG (msg_bc_ack_invalid() clear), sized so its data area is short, carrying a Gap ACK record with len = 0x400, bgack_cnt = 0xff and ugack_cnt = 0. len then equals struct_size(p, gacks, 255), so the consistency check passes and ga is non-NULL; kmemdup() reads struct_size(ga, gacks, 255) = 1024 bytes out of the much smaller skb: BUG: KASAN: slab-out-of-bounds in kmemdup_noprof+0x48/0x60 Read of size 1024 at addr ffff0000c7030d38 by task poc864/69 Call trace: kmemdup_noprof+0x48/0x60 tipc_link_advance_transmq+0x86c/0xb80 tipc_link_bc_ack_rcv+0x19c/0x1e0 tipc_bcast_sync_rcv+0x1c4/0x2c4 tipc_rcv+0x85c/0x1340 tipc_l2_rcv_msg+0xac/0x104 The buggy address belongs to the object at ffff0000c7030d00 which belongs to the cache skbuff_small_head of size 704 The buggy address is located 56 bytes inside of allocated 704-byte region [ffff0000c7030d00, ffff0000c7030fc0) The copied-out bytes are subsequently consumed as gap/ack values, but the read is already out of bounds at the kmemdup() regardless of how they are used. The unicast STATE path drops such a message: "if (glen > dlen) break;" skips the rest of STATE_MSG handling and the skb is freed. Make the broadcast path drop it too. tipc_bcast_sync_rcv() now bounds the record against msg_data_sz() and, when it does not fit, reports it back through tipc_node_bc_sync_rcv() to tipc_rcv() so the skb is discarded rather than processed. ga is not cleared on this path: ga == NULL already means "legacy peer without Selective ACK", a distinct legitimate state.•CVE-2026-64450

References

Sources include official advisories and independent security research.