Linux Kernel up to 6.19.5 Dm Driver blk_should_fake_timeout memory leak

Summaryinfo

A vulnerability, which was classified as critical, has been found in Linux Kernel up to 6.19.5. Affected is the function blk_should_fake_timeout of the component Dm Driver. Performing a manipulation results in memory leak. This vulnerability is reported as CVE-2026-43314. No exploit exists. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability classified as critical has been found in Linux Kernel up to 6.19.5. This affects the function blk_should_fake_timeout of the component Dm Driver. The manipulation with an unknown input leads to a memory leak vulnerability. CWE is classifying the issue as CWE-401. The product does not sufficiently track and release allocated memory after it has been used, which slowly consumes remaining memory. This is going to have an impact on availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: dm: remove fake timeout to avoid leak request Since commit 15f73f5b3e59 ("blk-mq: move failure injection out of blk_mq_complete_request"), drivers are responsible for calling blk_should_fake_timeout() at appropriate code paths and opportunities. However, the dm driver does not implement its own timeout handler and relies on the timeout handling of its slave devices. If an io-timeout-fail error is injected to a dm device, the request will be leaked and never completed, causing tasks to hang indefinitely. Reproduce: 1. prepare dm which has iscsi slave device 2. inject io-timeout-fail to dm echo 1 >/sys/class/block/dm-0/io-timeout-fail echo 100 >/sys/kernel/debug/fail_io_timeout/probability echo 10 >/sys/kernel/debug/fail_io_timeout/times 3. read/write dm 4. iscsiadm -m node -u Result: hang task like below [ 862.243768] INFO: task kworker/u514:2:151 blocked for more than 122 seconds. [ 862.244133] Tainted: G E 6.19.0-rc1+ #51 [ 862.244337] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 862.244718] task:kworker/u514:2 state:D stack:0 pid:151 tgid:151 ppid:2 task_flags:0x4288060 flags:0x00080000 [ 862.245024] Workqueue: iscsi_ctrl_3:1 __iscsi_unbind_session [scsi_transport_iscsi] [ 862.245264] Call Trace: [ 862.245587] <TASK> [ 862.245814] __schedule+0x810/0x15c0 [ 862.246557] schedule+0x69/0x180 [ 862.246760] blk_mq_freeze_queue_wait+0xde/0x120 [ 862.247688] elevator_change+0x16d/0x460 [ 862.247893] elevator_set_none+0x87/0xf0 [ 862.248798] blk_unregister_queue+0x12e/0x2a0 [ 862.248995] __del_gendisk+0x231/0x7e0 [ 862.250143] del_gendisk+0x12f/0x1d0 [ 862.250339] sd_remove+0x85/0x130 [sd_mod] [ 862.250650] device_release_driver_internal+0x36d/0x530 [ 862.250849] bus_remove_device+0x1dd/0x3f0 [ 862.251042] device_del+0x38a/0x930 [ 862.252095] __scsi_remove_device+0x293/0x360 [ 862.252291] scsi_remove_target+0x486/0x760 [ 862.252654] __iscsi_unbind_session+0x18a/0x3e0 [scsi_transport_iscsi] [ 862.252886] process_one_work+0x633/0xe50 [ 862.253101] worker_thread+0x6df/0xf10 [ 862.253647] kthread+0x36d/0x720 [ 862.254533] ret_from_fork+0x2a6/0x470 [ 862.255852] ret_from_fork_asm+0x1a/0x30 [ 862.256037] </TASK> Remove the blk_should_fake_timeout() check from dm, as dm has no native timeout handling and should not attempt to fake timeouts.

The advisory is shared at git.kernel.org. This vulnerability is uniquely identified as CVE-2026-43314 since 05/01/2026. The exploitability is told to be difficult. Technical details are known, but no exploit is available.

Upgrading to version 5.10.252, 5.15.202, 6.1.165, 6.6.128, 6.12.75, 6.18.16 or 6.19.6 eliminates this vulnerability. Applying the patch ece6720de9403260088209b0b92d45e0b49ff856/8200fca818c1e2f65bc6cb16d934ff6049302197/b307b6307f6459841312432bd4bc9519cbac97f5/4f9e7ca933a9fbf9912a384b061a00c77332cbf0/cf2d06c9fd4b6521ea5b7f73c99c64c2c6f5e224/6cdb21e0c9fdee484feba14fc9e72e9d07daf9f3/c8a23d4c995ef4227bd4de64cd3910637ee6162e/f3a9c95a15d2f4466acad5c68faeff79ca5e9f47 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2026-1454). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Affected

• Google Container-Optimized OS
• Debian Linux
• Red Hat Enterprise Linux
• SUSE Linux
• Oracle Linux
• SUSE openSUSE
• RESF Rocky Linux
• Microsoft Azure Linux
• Open Source Linux Kernel

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 5.10.251
• 5.15.201
• 6.1.164
• 6.6.127
• 6.12.0
• 6.12.1
• 6.12.2
• 6.12.3
• 6.12.4
• 6.12.5
• 6.12.6
• 6.12.7
• 6.12.8
• 6.12.9
• 6.12.10
• 6.12.11
• 6.12.12
• 6.12.13
• 6.12.14
• 6.12.15
• 6.12.16
• 6.12.17
• 6.12.18
• 6.12.19
• 6.12.20
• 6.12.21
• 6.12.22
• 6.12.23
• 6.12.24
• 6.12.25
• 6.12.26
• 6.12.27
• 6.12.28
• 6.12.29
• 6.12.30
• 6.12.31
• 6.12.32
• 6.12.33
• 6.12.34
• 6.12.35
• 6.12.36
• 6.12.37
• 6.12.38
• 6.12.39
• 6.12.40
• 6.12.41
• 6.12.42
• 6.12.43
• 6.12.44
• 6.12.45
• 6.12.46
• 6.12.47
• 6.12.48
• 6.12.49
• 6.12.50
• 6.12.51
• 6.12.52
• 6.12.53
• 6.12.54
• 6.12.55
• 6.12.56
• 6.12.57
• 6.12.58
• 6.12.59
• 6.12.60
• 6.12.61
• 6.12.62
• 6.12.63
• 6.12.64
• 6.12.65
• 6.12.66
• 6.12.67
• 6.12.68
• 6.12.69
• 6.12.70
• 6.12.71
• 6.12.72
• 6.12.73
• 6.12.74
• 6.18.0
• 6.18.1
• 6.18.2
• 6.18.3
• 6.18.4
• 6.18.5
• 6.18.6
• 6.18.7
• 6.18.8
• 6.18.9
• 6.18.10
• 6.18.11
• 6.18.12
• 6.18.13
• 6.18.14
• 6.18.15
• 6.19.0
• 6.19.1
• 6.19.2
• 6.19.3
• 6.19.4
• 6.19.5

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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CPE 2.2info

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CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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