{"id":"CVE-2024-57889","url":"https://www.cyber-defence.io/tools/cve/CVE-2024-57889","generatedAt":"2026-10-28T03:28:05.880Z","title":"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…","description":"In the Linux kernel, the following vulnerability has been resolved:\n\npinctrl: mcp23s08: Fix sleeping in atomic context due to regmap locking\n\nIf a device uses MCP23xxx IO expander to receive IRQs, the following\nbug can happen:\n\n  BUG: sleeping function called from invalid context\n    at kernel/locking/mutex.c:283\n  in_atomic(): 1, irqs_disabled(): 1, non_block: 0, ...\n  preempt_count: 1, expected: 0\n  ...\n  Call Trace:\n  ...\n  __might_resched+0x104/0x10e\n  __might_sleep+0x3e/0x62\n  mutex_lock+0x20/0x4c\n  regmap_lock_mutex+0x10/0x18\n  regmap_update_bits_base+0x2c/0x66\n  mcp23s08_irq_set_type+0x1ae/0x1d6\n  __irq_set_trigger+0x56/0x172\n  __setup_irq+0x1e6/0x646\n  request_threaded_irq+0xb6/0x160\n  ...\n\nWe observed the problem while experimenting with a touchscreen driver which\nused MCP23017 IO expander (I2C).\n\nThe regmap in the pinctrl-mcp23s08 driver uses a mutex for protection from\nconcurrent accesses, which is the default for regmaps without .fast_io,\n.disable_locking, etc.\n\nmcp23s08_irq_set_type() calls regmap_update_bits_base(), and the latter\nlocks the mutex.\n\nHowever, __setup_irq() locks desc->lock spinlock before calling these\nfunctions. As a result, the system tries to lock the mutex whole holding\nthe spinlock.\n\nIt seems, the internal regmap locks are not needed in this driver at all.\nmcp->lock seems to protect the regmap from concurrent accesses already,\nexcept, probably, in mcp_pinconf_get/set.\n\nmcp23s08_irq_set_type() and mcp23s08_irq_mask/unmask() are called under\nchip_bus_lock(), which calls mcp23s08_irq_bus_lock(). The latter takes\nmcp->lock and enables regmap caching, so that the potentially slow I2C\naccesses are deferred until chip_bus_unlock().\n\nThe accesses to the regmap from mcp23s08_probe_one() do not need additional\nlocking.\n\nIn all remaining places where the regmap is accessed, except\nmcp_pinconf_get/set(), the driver already takes mcp->lock.\n\nThis patch adds locking in mcp_pinconf_get/set() and disables internal\nlocking in the regmap config. Among other things, it fixes the sleeping\nin atomic context described above.","published":"2025-01-15T13:15:13.000Z","lastModified":"2026-06-17T08:14:09.000Z","status":"Modified","sourceIdentifier":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","cvss":{"version":"3.1","score":5.5,"severity":"MEDIUM","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"},"cwe":["CWE-667"],"affected":["linux/linux kernel"],"epss":{"score":0.00166,"percentile":0.05764,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.17%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"https://git.kernel.org/stable/c/0310cbad163a908d09d99c26827859365cd71fcb","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/788d9e9a41b81893d6bb8faa05f045c975278318","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/830f838589522404cd7c2f0f540602f25034af61","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/8c6fd5803b988a5e78c9b9e42c70a936d7cfc6ec","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/9372e160d8211a7e17f2abff8370794f182df785","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/a37eecb705f33726f1fb7cd2a67e514a15dfe693","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/c55d186376a87b468c9ee30f2195e0f3857f61a0","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://lists.debian.org/debian-lts-announce/2025/03/msg00001.html","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.debian.org/debian-lts-announce/2025/03/msg00002.html","source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2024-57889","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}