Vulnerabilities > CVE-2024-42294 - Improper Locking vulnerability in Linux Kernel
Summary
In the Linux kernel, the following vulnerability has been resolved: block: fix deadlock between sd_remove & sd_release Our test report the following hung task: [ 2538.459400] INFO: task "kworker/0:0":7 blocked for more than 188 seconds. [ 2538.459427] Call trace: [ 2538.459430] __switch_to+0x174/0x338 [ 2538.459436] __schedule+0x628/0x9c4 [ 2538.459442] schedule+0x7c/0xe8 [ 2538.459447] schedule_preempt_disabled+0x24/0x40 [ 2538.459453] __mutex_lock+0x3ec/0xf04 [ 2538.459456] __mutex_lock_slowpath+0x14/0x24 [ 2538.459459] mutex_lock+0x30/0xd8 [ 2538.459462] del_gendisk+0xdc/0x350 [ 2538.459466] sd_remove+0x30/0x60 [ 2538.459470] device_release_driver_internal+0x1c4/0x2c4 [ 2538.459474] device_release_driver+0x18/0x28 [ 2538.459478] bus_remove_device+0x15c/0x174 [ 2538.459483] device_del+0x1d0/0x358 [ 2538.459488] __scsi_remove_device+0xa8/0x198 [ 2538.459493] scsi_forget_host+0x50/0x70 [ 2538.459497] scsi_remove_host+0x80/0x180 [ 2538.459502] usb_stor_disconnect+0x68/0xf4 [ 2538.459506] usb_unbind_interface+0xd4/0x280 [ 2538.459510] device_release_driver_internal+0x1c4/0x2c4 [ 2538.459514] device_release_driver+0x18/0x28 [ 2538.459518] bus_remove_device+0x15c/0x174 [ 2538.459523] device_del+0x1d0/0x358 [ 2538.459528] usb_disable_device+0x84/0x194 [ 2538.459532] usb_disconnect+0xec/0x300 [ 2538.459537] hub_event+0xb80/0x1870 [ 2538.459541] process_scheduled_works+0x248/0x4dc [ 2538.459545] worker_thread+0x244/0x334 [ 2538.459549] kthread+0x114/0x1bc [ 2538.461001] INFO: task "fsck.":15415 blocked for more than 188 seconds. [ 2538.461014] Call trace: [ 2538.461016] __switch_to+0x174/0x338 [ 2538.461021] __schedule+0x628/0x9c4 [ 2538.461025] schedule+0x7c/0xe8 [ 2538.461030] blk_queue_enter+0xc4/0x160 [ 2538.461034] blk_mq_alloc_request+0x120/0x1d4 [ 2538.461037] scsi_execute_cmd+0x7c/0x23c [ 2538.461040] ioctl_internal_command+0x5c/0x164 [ 2538.461046] scsi_set_medium_removal+0x5c/0xb0 [ 2538.461051] sd_release+0x50/0x94 [ 2538.461054] blkdev_put+0x190/0x28c [ 2538.461058] blkdev_release+0x28/0x40 [ 2538.461063] __fput+0xf8/0x2a8 [ 2538.461066] __fput_sync+0x28/0x5c [ 2538.461070] __arm64_sys_close+0x84/0xe8 [ 2538.461073] invoke_syscall+0x58/0x114 [ 2538.461078] el0_svc_common+0xac/0xe0 [ 2538.461082] do_el0_svc+0x1c/0x28 [ 2538.461087] el0_svc+0x38/0x68 [ 2538.461090] el0t_64_sync_handler+0x68/0xbc [ 2538.461093] el0t_64_sync+0x1a8/0x1ac T1: T2: sd_remove del_gendisk __blk_mark_disk_dead blk_freeze_queue_start ++q->mq_freeze_depth bdev_release mutex_lock(&disk->open_mutex) sd_release scsi_execute_cmd blk_queue_enter wait_event(!q->mq_freeze_depth) mutex_lock(&disk->open_mutex) SCSI does not set GD_OWNS_QUEUE, so QUEUE_FLAG_DYING is not set in this scenario. This is a classic ABBA deadlock. To fix the deadlock, make sure we don't try to acquire disk->open_mutex after freezing the queue.
Vulnerable Configurations
Common Weakness Enumeration (CWE)
Common Attack Pattern Enumeration and Classification (CAPEC)
- Leveraging Race Conditions This attack targets a race condition occurring when multiple processes access and manipulate the same resource concurrently and the outcome of the execution depends on the particular order in which the access takes place. The attacker can leverage a race condition by "running the race", modifying the resource and modifying the normal execution flow. For instance a race condition can occur while accessing a file, the attacker can trick the system by replacing the original file with his version and cause the system to read the malicious file.
- Leveraging Race Conditions via Symbolic Links This attack leverages the use of symbolic links (Symlinks) in order to write to sensitive files. An attacker can create a Symlink link to a target file not otherwise accessible to her. When the privileged program tries to create a temporary file with the same name as the Symlink link, it will actually write to the target file pointed to by the attackers' Symlink link. If the attacker can insert malicious content in the temporary file she will be writing to the sensitive file by using the Symlink. The race occurs because the system checks if the temporary file exists, then creates the file. The attacker would typically create the Symlink during the interval between the check and the creation of the temporary file.