UBUNTU-CVE-2026-79978

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Source
https://ubuntu.com/security/CVE-2026-79978
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-79978.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-79978
Upstream
Published
2026-10-26T00:00:00Z
Modified
2026-10-27T04:17:56Z
Severity
  • 3.6 (Low) CVSS_V3 - CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:L CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

The RTIO streaming completion callback adxl345_process_fifo_samples_cb() in drivers/sensor/adi/adxl345/adxl345_stream.c clamps the amount of FIFO data it will report (read_len = MIN(fifo_bytes, buf_avail)) to the space actually returned by rtio_sqe_rx_buf(), but then queues one 6-byte bus read per hardware FIFO entry at consecutive offsets from read_buf, bounded by the device-reported entry count rather than by the clamp. When the allocated buffer is smaller than a full batch, the driver writes up to 186 bytes past the end of the allocation; a companion defect left data->fifo_total_bytes un-reset at batch start, so an aborted or errored chain could leave a stale write offset that pushes the next batch's writes out of bounds as well. A short buffer is an expected, first-class outcome of the RTIO allocator: rtio_block_pool_alloc() walks the requested size down one block at a time until a contiguous run is available, and the driver only demands sizeof(struct adxl345_fifo_data) + 6 bytes as its minimum. Any streaming configuration whose mempool block granularity is smaller than a full FIFO batch (204 bytes) — for example the sensor shell's RTIO_DEFINE_WITH_MEMPOOL(sensor_read_rtio, 8, 8, 32, 64, 4) used by sensor stream on fifo_wm incl, or the 16-byte-block streaming example in the documentation — takes this path whenever the pool is fragmented or the consuming thread falls behind. The out-of-bounds writes are performed by the I2C/SPI RTIO backend (DMA on many SoCs) into the shared RTIO block pool, corrupting neighbouring live buffers or, for a pool smaller than one batch, memory beyond the pool itself. The written bytes are accelerometer samples and the destination follows the allocation, so there is no controllable corruption primitive: the realistic impact is silent corruption of other RTIO consumers' data or a crash. Reaching it requires a board with an interrupt-wired ADXL345 built with CONFIG_ADXL345_STREAM, plus buffer-pool starvation, which a co-resident local workload can induce but which also occurs spontaneously under load; there is no network, USB or radio path to this code.

References

Affected packages

Ubuntu:16.04:LTS
zephyr

Package

Name
zephyr
Purl
pkg:deb/ubuntu/zephyr?arch=source&distro=xenial

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected

Affected versions

3.*
3.1.2-1
3.1.2-1build1

Ecosystem specific 

{
    "binaries":  [
        {
            "binary_name":  "libzephyr4",
            "binary_version":  "3.1.2-1build1"
        },
        {
            "binary_name":  "libzephyr4-krb5",
            "binary_version":  "3.1.2-1build1"
        },
        {
            "binary_name":  "zephyr-clients",
            "binary_version":  "3.1.2-1build1"
        },
        {
            "binary_name":  "zephyr-server",
            "binary_version":  "3.1.2-1build1"
        },
        {
            "binary_name":  "zephyr-server-krb5",
            "binary_version":  "3.1.2-1build1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-79978.json"
Ubuntu:18.04:LTS
zephyr

Package

Name
zephyr
Purl
pkg:deb/ubuntu/zephyr?arch=source&distro=bionic

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected

Affected versions

3.*
3.1.2-1build1
3.1.2-1build2

Ecosystem specific 

{
    "binaries":  [
        {
            "binary_name":  "libzephyr4",
            "binary_version":  "3.1.2-1build2"
        },
        {
            "binary_name":  "libzephyr4-krb5",
            "binary_version":  "3.1.2-1build2"
        },
        {
            "binary_name":  "zephyr-clients",
            "binary_version":  "3.1.2-1build2"
        },
        {
            "binary_name":  "zephyr-server",
            "binary_version":  "3.1.2-1build2"
        },
        {
            "binary_name":  "zephyr-server-krb5",
            "binary_version":  "3.1.2-1build2"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-79978.json"
Ubuntu:20.04:LTS
zephyr

Package

Name
zephyr
Purl
pkg:deb/ubuntu/zephyr?arch=source&distro=focal

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected

Affected versions

3.*
3.1.2-1build3

Ecosystem specific 

{
    "binaries":  [
        {
            "binary_name":  "libzephyr4",
            "binary_version":  "3.1.2-1build3"
        },
        {
            "binary_name":  "libzephyr4-krb5",
            "binary_version":  "3.1.2-1build3"
        },
        {
            "binary_name":  "zephyr-clients",
            "binary_version":  "3.1.2-1build3"
        },
        {
            "binary_name":  "zephyr-server",
            "binary_version":  "3.1.2-1build3"
        },
        {
            "binary_name":  "zephyr-server-krb5",
            "binary_version":  "3.1.2-1build3"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-79978.json"
Ubuntu:22.04:LTS
zephyr

Package

Name
zephyr
Purl
pkg:deb/ubuntu/zephyr?arch=source&distro=jammy

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected

Affected versions

3.*
3.1.2-1build3

Ecosystem specific 

{
    "binaries":  [
        {
            "binary_name":  "libzephyr4",
            "binary_version":  "3.1.2-1build3"
        },
        {
            "binary_name":  "libzephyr4-krb5",
            "binary_version":  "3.1.2-1build3"
        },
        {
            "binary_name":  "zephyr-clients",
            "binary_version":  "3.1.2-1build3"
        },
        {
            "binary_name":  "zephyr-server",
            "binary_version":  "3.1.2-1build3"
        },
        {
            "binary_name":  "zephyr-server-krb5",
            "binary_version":  "3.1.2-1build3"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-79978.json"
Ubuntu:24.04:LTS
zephyr

Package

Name
zephyr
Purl
pkg:deb/ubuntu/zephyr?arch=source&distro=noble

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected

Affected versions

3.*
3.1.2-1.1
3.1.2-1.1build1

Ecosystem specific 

{
    "binaries":  [
        {
            "binary_name":  "libzephyr4",
            "binary_version":  "3.1.2-1.1build1"
        },
        {
            "binary_name":  "libzephyr4-krb5",
            "binary_version":  "3.1.2-1.1build1"
        },
        {
            "binary_name":  "zephyr-clients",
            "binary_version":  "3.1.2-1.1build1"
        },
        {
            "binary_name":  "zephyr-server",
            "binary_version":  "3.1.2-1.1build1"
        },
        {
            "binary_name":  "zephyr-server-krb5",
            "binary_version":  "3.1.2-1.1build1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-79978.json"
Ubuntu:26.04:LTS
zephyr

Package

Name
zephyr
Purl
pkg:deb/ubuntu/zephyr?arch=source&distro=resolute

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected

Affected versions

3.*
3.1.2-1.1build1
3.1.2-4

Ecosystem specific 

{
    "binaries":  [
        {
            "binary_name":  "libzephyr4",
            "binary_version":  "3.1.2-4"
        },
        {
            "binary_name":  "libzephyr4-krb5",
            "binary_version":  "3.1.2-4"
        },
        {
            "binary_name":  "zephyr-clients",
            "binary_version":  "3.1.2-4"
        },
        {
            "binary_name":  "zephyr-server",
            "binary_version":  "3.1.2-4"
        },
        {
            "binary_name":  "zephyr-server-krb5",
            "binary_version":  "3.1.2-4"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-79978.json"
Ubuntu:26.10
zephyr

Package

Name
zephyr
Purl
pkg:deb/ubuntu/zephyr?arch=source&distro=stonking

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected

Affected versions

3.*
3.1.2-4

Ecosystem specific 

{
    "binaries":  [
        {
            "binary_name":  "libzephyr4",
            "binary_version":  "3.1.2-4"
        },
        {
            "binary_name":  "libzephyr4-krb5",
            "binary_version":  "3.1.2-4"
        },
        {
            "binary_name":  "zephyr-clients",
            "binary_version":  "3.1.2-4"
        },
        {
            "binary_name":  "zephyr-server",
            "binary_version":  "3.1.2-4"
        },
        {
            "binary_name":  "zephyr-server-krb5",
            "binary_version":  "3.1.2-4"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-79978.json"