CVE-2026-53204

firmware: stratix10-rsu: Fix NULL deref on rsu_send_msg() timeout in probe

Published Jun 25, 2026 CVSS 3.1 · 5.5 Medium EPSS < 1% KEV · Not listed
Description
In the Linux kernel, the following vulnerability has been resolved:

firmware: stratix10-rsu: Fix NULL deref on rsu_send_msg() timeout in probe

rsu_send_msg() can return -ETIMEDOUT when
wait_for_completion_interruptible_timeout() fires while the SMC call is still
pending. In stratix10_rsu_probe(), the error paths for COMMAND_RSU_DCMF_VERSION,
COMMAND_RSU_DCMF_STATUS, COMMAND_RSU_MAX_RETRY and COMMAND_RSU_GET_SPT_TABLE
call stratix10_svc_free_channel() - which sets chan->scl to NULL - but then
fall through and queue the next request on the same channel. The next svc
kthread that runs will dereference pdata->chan->scl in its receive callback
path, triggering a NULL pointer dereference identical to the one fixed by
commit c45f7263100c ("firmware: stratix10-rsu: Fix NULL pointer dereference
when RSU is disabled") for the COMMAND_RSU_STATUS path.

Apply the same cleanup pattern to the remaining failure paths: remove the
async client, free the channel, and return early so no further messages are
queued on a channel whose scl has been cleared.

While at it, clean up stratix10_rsu_probe() in two ways without changing
behavior:

- Drop redundant zero-initialization of fields already cleared by
devm_kzalloc(): client.receive_cb, status.* and spt0/1_address
(INVALID_SPT_ADDRESS is 0x0).

- Replace five identical 3-line error-cleanup blocks
(stratix10_svc_remove_async_client() + stratix10_svc_free_channel() +
return ret) with goto labels (remove_async_client, free_channel),
matching the standard kernel resource-unwinding pattern and making it
easier to extend the probe sequence without forgetting matching
cleanup.

Also move init_completion() next to mutex_init() so sync-primitive
initialization is grouped before anything that could trigger a
callback.

---
v2: Add a minor clean-up of the function stratix10_rsu_probe() to have a
centralize exit for all the rsu_send_async_msg() and rsu_send_msg().

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Ubuntu USN Ubuntu USN USN-8726-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8727-1 Linux kernel (OEM) vulnerabilities
Ubuntu USN Ubuntu USN USN-8728-1 Linux kernel (GCP) vulnerabilities
Ubuntu USN Ubuntu USN USN-8760-1 Linux kernel (NVIDIA) vulnerabilities
Ubuntu USN Ubuntu USN USN-8726-2 Linux kernel (Raspberry Pi) vulnerabilities
Ubuntu USN Ubuntu USN USN-8726-3 Linux kernel (IBM) vulnerabilities
Ubuntu USN Ubuntu USN USN-8800-1 Linux kernel (NVIDIA BaseOS) vulnerabilities
Ubuntu USN Ubuntu USN USN-8760-2 Linux kernel (NVIDIA) vulnerabilities
Ubuntu USN Ubuntu USN USN-8726-4 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8728-2 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-8728-3 Linux kernel (Oracle) vulnerabilities
History
Type Values Removed Values Added
Weaknesses CWE-476
Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: firmware: stratix10-rsu: Fix NULL deref on rsu_send_msg() timeout in probe rsu_send_msg() can return -ETIMEDOUT when wait_for_completion_interruptible_timeout() fires while the SMC call is still pending. In stratix10_rsu_probe(), the error paths for COMMAND_RSU_DCMF_VERSION, COMMAND_RSU_DCMF_STATUS, COMMAND_RSU_MAX_RETRY and COMMAND_RSU_GET_SPT_TABLE call stratix10_svc_free_channel() - which sets chan->scl to NULL - but then fall through and queue the next request on the same channel. The next svc kthread that runs will dereference pdata->chan->scl in its receive callback path, triggering a NULL pointer dereference identical to the one fixed by commit c45f7263100c ("firmware: stratix10-rsu: Fix NULL pointer dereference when RSU is disabled") for the COMMAND_RSU_STATUS path. Apply the same cleanup pattern to the remaining failure paths: remove the async client, free the channel, and return early so no further messages are queued on a channel whose scl has been cleared. While at it, clean up stratix10_rsu_probe() in two ways without changing behavior: - Drop redundant zero-initialization of fields already cleared by devm_kzalloc(): client.receive_cb, status.* and spt0/1_address (INVALID_SPT_ADDRESS is 0x0). - Replace five identical 3-line error-cleanup blocks (stratix10_svc_remove_async_client() + stratix10_svc_free_channel() + return ret) with goto labels (remove_async_client, free_channel), matching the standard kernel resource-unwinding pattern and making it easier to extend the probe sequence without forgetting matching cleanup. Also move init_completion() next to mutex_init() so sync-primitive initialization is grouped before anything that could trigger a callback. --- v2: Add a minor clean-up of the function stratix10_rsu_probe() to have a centralize exit for all the rsu_send_async_msg() and rsu_send_msg().
Title firmware: stratix10-rsu: Fix NULL deref on rsu_send_msg() timeout in probe
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
Linux
Published
Updated
Jun 25, 2026, 8:39 AM
Reserved
Jun 9, 2026, 7:44 AM
Status
Analyzed
Published
Jun 25, 2026, 9:16 AM
Modified
Jul 2, 2026, 8:55 PM
Severity
Public date
Jun 25, 2026, 12:00 AM