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Fencer Vulns
medium 5.5

CVE-2024-57889 json

pinctrl: mcp23s08: Fix sleeping in atomic context due to regmap locking

published 2025-01-15 21 mo ago modified 2026-06-17 4 mo ago also EUVD-2024-53792

cvss
5.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 5%
public exploits
0
none known

Summary

In the Linux kernel, the following vulnerability has been resolved:

pinctrl: mcp23s08: Fix sleeping in atomic context due to regmap locking

If a device uses MCP23xxx IO expander to receive IRQs, the following bug can happen:

BUG: sleeping function called from invalid context at kernel/locking/mutex.c:283 in_atomic(): 1, irqs_disabled(): 1, non_block: 0, ... preempt_count: 1, expected: 0 ... Call Trace: ... __might_resched+0x104/0x10e __might_sleep+0x3e/0x62 mutex_lock+0x20/0x4c regmap_lock_mutex+0x10/0x18 regmap_update_bits_base+0x2c/0x66 mcp23s08_irq_set_type+0x1ae/0x1d6 __irq_set_trigger+0x56/0x172 __setup_irq+0x1e6/0x646 request_threaded_irq+0xb6/0x160 ...

We observed the problem while experimenting with a touchscreen driver which used MCP23017 IO expander (I2C).

The regmap in the pinctrl-mcp23s08 driver uses a mutex for protection from concurrent accesses, which is the default for regmaps without .fast_io, .disable_locking, etc.

mcp23s08_irq_set_type() calls regmap_update_bits_base(), and the latter locks the mutex.

However, __setup_irq() locks desc->lock spinlock before calling these functions. As a result, the system tries to lock the mutex whole holding the spinlock.

It seems, the internal regmap locks are not needed in this driver at all. mcp->lock seems to protect the regmap from concurrent accesses already, except, probably, in mcp_pinconf_get/set.

mcp23s08_irq_set_type() and mcp23s08_irq_mask/unmask() are called under chip_bus_lock(), which calls mcp23s08_irq_bus_lock(). The latter takes mcp->lock and enables regmap caching, so that the potentially slow I2C accesses are deferred until chip_bus_unlock().

The accesses to the regmap from mcp23s08_probe_one() do not need additional locking.

In all remaining places where the regmap is accessed, except mcp_pinconf_get/set(), the driver already takes mcp->lock.

This patch adds locking in mcp_pinconf_get/set() and disables internal locking in the regmap config. Among other things, it fixes the sleeping in atomic context described above.

Patch / fix

  • Linux Linux 5.4.289, 5.10.233, 5.15.176, 6.1.124, 6.6.70, 6.12.9, 6.13
  • linux Debian 12 6.1.124-1
  • linux Debian 14, Debian 13 6.12.9-1

debian advisories DEBIAN-CVE-2024-57889

  • linux Ubuntu 20.04 LTS 5.4.0-211.231
  • linux Ubuntu 22.04 LTS 5.15.0-135.146
  • linux Ubuntu 24.04 LTS 6.8.0-60.63
  • linux-aws Ubuntu 20.04 LTS 5.4.0-1142.152
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1080.87
  • linux-aws Ubuntu 24.04 LTS 6.8.0-1029.31
  • linux-gcp Ubuntu 20.04 LTS 5.4.0-1145.154
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1079.88

ubuntu advisories UBUNTU-CVE-2024-57889

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • kernel-source Linux Micro 6.1, Linux Micro 6.0 6.4.0-28.1
  • kernel-default Linux Micro 6.1, Linux Micro 6.0 6.4.0-28.1
  • kernel-kvmsmall Linux Micro 6.1, Linux Micro 6.0 6.4.0-28.1
  • kernel-default-base Linux Micro 6.1, Linux Micro 6.0 6.4.0-28.1.21.6
  • kernel-livepatch-MICRO-6-0_Update_6 Linux Micro 6.1, Linux Micro 6.0 1-3.1
  • kernel-rt Linux Micro 6.1, Linux Micro 6.0 6.4.0-28.1
  • kernel-source-rt Linux Micro 6.1, Linux Micro 6.0 6.4.0-28.1
  • kernel-livepatch-MICRO-6-0-RT_Update_6 Linux Micro 6.1, Linux Micro 6.0 1-3.1

suse advisories SUSE-SU-2025:20192-1SUSE-SU-2025:20270-1SUSE-SU-2025:20190-1SUSE-SU-2025:20260-1SUSE-SU-2025:0955-1SUSE-SU-2025:0856-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2024-57889 updated

kernel: pinctrl: mcp23s08: Fix sleeping in atomic context due to regmap locking

  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more Red Hat Enterprise Linux 10 kernel
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.17% chance of exploitation in the next 30 days, higher than 5% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products

  • Linux Linux

Classification

Weakness
Technology feeds

References

Sources

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