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NVD / CVE Program· CNA Linux

CVE-2022-49753: dmaengine: Fix double increment of client_count in dma_chan_get()

Noroxi assessment

Priority: Monitor (action score 31/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.23% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 142d644fd2cc059ffa042fbfb68e766433ef3afd, 18dd3b30d4c7e8440c63118c7a7b687372b9567f, 1b409e14b4b7af034e0450f95c165b6c5c87dbc1.

Low priority for now. Upgrade to Linux Linux 142d644fd2cc059ffa042fbfb68e766433ef3afd, 18dd3b30d4c7e8440c63118c7a7b687372b9567f, 1b409e14b4b7af034e0450f95c165b6c5c87dbc1 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: dmaengine: Fix double increment of client_count in dma_chan_get() The first time dma_chan_get() is called for a channel the channel client_count is incorrectly incremented twice for public channels, first in balance_ref_count(), and again prior to returning. This results in an incorrect client count which will lead to the channel resources not being freed when they should be. A simple test of repeated module load and unload of async_tx on a Dell Power Edge R7425 also shows this resulting in a kref underflow warning. [ 124.329662] async_tx: api initialized (async) [ 129.000627] async_tx: api initialized (async) [ 130.047839] ------------[ cut here ]------------ [ 130.052472] refcount_t: underflow; use-after-free. [ 130.057279] WARNING: CPU: 3 PID: 19364 at lib/refcount.c:28 refcount_warn_saturate+0xba/0x110 [ 130.065811] Modules linked in: async_tx(-) rfkill intel_rapl_msr intel_rapl_common amd64_edac edac_mce_amd ipmi_ssif kvm_amd dcdbas kvm mgag200 drm_shmem_helper acpi_ipmi irqbypass drm_kms_helper ipmi_si syscopyarea sysfillrect rapl pcspkr ipmi_devintf sysimgblt fb_sys_fops k10temp i2c_piix4 ipmi_msghandler acpi_power_meter acpi_cpufreq vfat fat drm fuse xfs libcrc32c sd_mod t10_pi sg ahci crct10dif_pclmul libahci crc32_pclmul crc32c_intel ghash_clmulni_intel igb megaraid_sas i40e libata i2c_algo_bit ccp sp5100_tco dca dm_mirror dm_region_hash dm_log dm_mod [last unloaded: async_tx] [ 130.117361] CPU: 3 PID: 19364 Comm: modprobe Kdump: loaded Not tainted 5.14.0-185.el9.x86_64 #1 [ 130.126091] Hardware name: Dell Inc. PowerEdge R7425/02MJ3T, BIOS 1.18.0 01/17/2022 [ 130.133806] RIP: 0010:refcount_warn_saturate+0xba/0x110 [ 130.139041] Code: 01 01 e8 6d bd 55 00 0f 0b e9 72 9d 8a 00 80 3d 26 18 9c 01 00 75 85 48 c7 c7 f8 a3 03 9d c6 05 16 18 9c 01 01 e8 4a bd 55 00 <0f> 0b e9 4f 9d 8a 00 80 3d 01 18 9c 01 00 0f 85 5e ff ff ff 48 c7 [ 130.157807] RSP: 0018:ffffbf98898afe68 EFLAGS: 00010286 [ 130.163036] RAX: 0000000000000000 RBX: ffff9da06028e598 RCX: 0000000000000000 [ 130.170172] RDX: ffff9daf9de26480 RSI: ffff9daf9de198a0 RDI: ffff9daf9de198a0 [ 130.177316] RBP: ffff9da7cddf3970 R08: 0000000000000000 R09: 00000000ffff7fff [ 130.184459] R10: ffffbf98898afd00 R11: ffffffff9d9e8c28 R12: ffff9da7cddf1970 [ 130.191596] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 130.198739] FS: 00007f646435c740(0000) GS:ffff9daf9de00000(0000) knlGS:0000000000000000 [ 130.206832] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 130.212586] CR2: 00007f6463b214f0 CR3: 00000008ab98c000 CR4: 00000000003506e0 [ 130.219729] Call Trace: [ 130.222192] <TASK> [ 130.224305] dma_chan_put+0x10d/0x110 [ 130.227988] dmaengine_put+0x7a/0xa0 [ 130.231575] __do_sys_delete_module.constprop.0+0x178/0x280 [ 130.237157] ? syscall_trace_enter.constprop.0+0x145/0x1d0 [ 130.242652] do_syscall_64+0x5c/0x90 [ 130.246240] ? exc_page_fault+0x62/0x150 [ 130.250178] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 130.255243] RIP: 0033:0x7f6463a3f5ab [ 130.258830] Code: 73 01 c3 48 8b 0d 75 a8 1b 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa b8 b0 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 45 a8 1b 00 f7 d8 64 89 01 48 [ 130.277591] RSP: 002b:00007fff22f972c8 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0 [ 130.285164] RAX: ffffffffffffffda RBX: 000055b6786edd40 RCX: 00007f6463a3f5ab [ 130.292303] RDX: 0000000000000000 RSI: 0000000000000800 RDI: 000055b6786edda8 [ 130.299443] RBP: 000055b6786edd40 R08: 0000000000000000 R09: 0000000000000000 [ 130.306584] R10: 00007f6463b9eac0 R11: 0000000000000206 R12: 000055b6786edda8 [ 130.313731] R13: 0000000000000000 R14: 000055b6786edda8 R15: 00007fff22f995f8 [ 130.320875] </TASK> [ 130.323081] ---[ end trace eff7156d56b5cf25 ]--- cat /sys/class/dma/dma0chan*/in_use would get the wrong result. 2 2 2 Test-by: Jie Hai <haijie1@huawei.com>

HighCVSS 7.8 · v3.1—No exploit Fix available
Published
Mar 27, 2025
Updated
Jun 17, 2026
EPSS
0.2% · 14th percentile

Report tools

JSON

Action score

31

Monitor

Low priority for now.

CVSS
31 / 40 · 7.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
linuxlinux kernel

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • linux linux kernel4.0 and later · before 4.14.305
  • linux linux kernel4.15 and later · before 4.19.272
  • linux linux kernel4.20 and later · before 5.4.231
  • linux linux kernel5.5 and later · before 5.10.166
  • linux linux kernel5.11 and later · before 5.15.91
  • linux linux kernel5.16 and later · before 6.1.9
  • linux linux kernel6.2

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 4.0affected
    • d2f4f99db3e9ec8b063cf2e45704e2bb95428317 and later · before 1b409e14b4b7af034e0450f95c165b6c5c87dbc1affected · git
    • d2f4f99db3e9ec8b063cf2e45704e2bb95428317 and later · before c6221afe573413fd2981e291f7df4a58283e0654affected · git
    • d2f4f99db3e9ec8b063cf2e45704e2bb95428317 and later · before 18dd3b30d4c7e8440c63118c7a7b687372b9567faffected · git
    • d2f4f99db3e9ec8b063cf2e45704e2bb95428317 and later · before 42ecd72f02cd657b00b559621e7ef7d2c4d3e5f1affected · git
    • d2f4f99db3e9ec8b063cf2e45704e2bb95428317 and later · before 71c601965532c38030133535f7cd93c1efa75af1affected · git
    • d2f4f99db3e9ec8b063cf2e45704e2bb95428317 and later · before 142d644fd2cc059ffa042fbfb68e766433ef3afdaffected · git
    • d2f4f99db3e9ec8b063cf2e45704e2bb95428317 and later · before f3dc1b3b4750851a94212dba249703dd0e50bb20affected · git
    • before 4.0not affected · semver
    • 4.14.305 and later · up to and including 4.14.*not affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.11-16.1.11-1
SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOSkernel-64kbbefore 5.14.21-150400.24.161.15.14.21-150400.24.161.1
SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOSkernel-docsbefore 5.14.21-150400.24.161.15.14.21-150400.24.161.1
SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOSkernel-obs-buildbefore 5.14.21-150400.24.161.15.14.21-150400.24.161.1
SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOSkernel-sourcebefore 5.14.21-150400.24.161.15.14.21-150400.24.161.1
SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOSkernel-symsbefore 5.14.21-150400.24.161.15.14.21-150400.24.161.1
SUSE:Linux Enterprise Live Patching 15 SP4kernel-livepatch-SLE15-SP4_Update_39before 1-150400.9.3.11-150400.9.3.1
SUSE:Linux Enterprise Micro 5.3kernel-defaultbefore 5.14.21-150400.24.161.15.14.21-150400.24.161.1
SUSE:Linux Enterprise Micro 5.3kernel-default-basebefore 5.14.21-150400.24.161.1.150400.24.80.15.14.21-150400.24.161.1.150400.24.80.1
SUSE:Linux Enterprise Server 15 SP4-LTSSkernel-zfcpdumpbefore 5.14.21-150400.24.161.15.14.21-150400.24.161.1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now

Published before and after this one in the same product

  • ← EarlierCVE-2022-49751Mar 27, 2025 · w1: fix WARNING after calling w1_process()
    22Monitor
  • ← EarlierCVE-2022-49752Mar 27, 2025 · device property: fix of node refcount leak in fwnode_graph_get_next_endpoint()
    22Monitor
  • Later →CVE-2022-49754Mar 27, 2025 · Bluetooth: Fix a buffer overflow in mgmt_mesh_add()
    31Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux142d644fd2cc059ffa042fbfb68e766433ef3afdVendor (CNA)
Linux Linux18dd3b30d4c7e8440c63118c7a7b687372b9567fVendor (CNA)
Linux Linux1b409e14b4b7af034e0450f95c165b6c5c87dbc1Vendor (CNA)
Linux Linux42ecd72f02cd657b00b559621e7ef7d2c4d3e5f1Vendor (CNA)
Linux Linux71c601965532c38030133535f7cd93c1efa75af1Vendor (CNA)
Linux Linuxc6221afe573413fd2981e291f7df4a58283e0654Vendor (CNA)
Linux Linuxf3dc1b3b4750851a94212dba249703dd0e50bb20Vendor (CNA)
debian:linux6.1.11-1 · Debian:12Package registry (OSV)
suse:kernel-64kb5.14.21-150400.24.161.1 · SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOSPackage registry (OSV)
suse:kernel-default5.14.21-150400.24.161.1 · SUSE:Linux Enterprise Micro 5.3Package registry (OSV)
suse:kernel-default-base5.14.21-150400.24.161.1.150400.24.80.1 · SUSE:Linux Enterprise Micro 5.3Package registry (OSV)
suse:kernel-docs5.14.21-150400.24.161.1 · SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOSPackage registry (OSV)
suse:kernel-livepatch-SLE15-SP4_Update_391-150400.9.3.1 · SUSE:Linux Enterprise Live Patching 15 SP4Package registry (OSV)
suse:kernel-obs-build5.14.21-150400.24.161.1 · SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOSPackage registry (OSV)
suse:kernel-source5.14.21-150400.24.161.1 · SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOSPackage registry (OSV)
suse:kernel-syms5.14.21-150400.24.161.1 · SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOSPackage registry (OSV)
suse:kernel-zfcpdump5.14.21-150400.24.161.1 · SUSE:Linux Enterprise Server 15 SP4-LTSSPackage registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-416 · Use After Free

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

nvd-secondary

Root cause

After a memory region is freed, another reference pointing to it is still used. By then, the same region may have been allocated for different data.

The bug in code

The whole CWE-416 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

c
free(dev->buf);/* ... another thread is still running ... */process(dev->buf);

Fixed

c
lock(&dev->lock);free(dev->buf);dev->buf = NULL;unlock(&dev->lock);

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (6 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records