n 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.
Configuration 1 (hide)
|
03 Nov 2025, 21:18
| Type | Values Removed | Values Added |
|---|---|---|
| References |
|
26 Sep 2025, 20:02
| Type | Values Removed | Values Added |
|---|---|---|
| CWE | CWE-667 | |
| First Time |
Linux
Linux linux Kernel |
|
| References | () https://git.kernel.org/stable/c/0310cbad163a908d09d99c26827859365cd71fcb - Patch | |
| References | () https://git.kernel.org/stable/c/788d9e9a41b81893d6bb8faa05f045c975278318 - Patch | |
| References | () https://git.kernel.org/stable/c/830f838589522404cd7c2f0f540602f25034af61 - Patch | |
| References | () https://git.kernel.org/stable/c/8c6fd5803b988a5e78c9b9e42c70a936d7cfc6ec - Patch | |
| References | () https://git.kernel.org/stable/c/9372e160d8211a7e17f2abff8370794f182df785 - Patch | |
| References | () https://git.kernel.org/stable/c/a37eecb705f33726f1fb7cd2a67e514a15dfe693 - Patch | |
| References | () https://git.kernel.org/stable/c/c55d186376a87b468c9ee30f2195e0f3857f61a0 - Patch | |
| CPE | cpe:2.3:o:linux:linux_kernel:6.13:rc3:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.13:rc5:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.13:rc2:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.13:rc1:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.13:rc4:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
|
| Summary |
|
|
| CVSS |
v2 : v3 : |
v2 : unknown
v3 : 5.5 |
15 Jan 2025, 13:15
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Published : 2025-01-15 13:15
Updated : 2025-11-03 21:18
NVD link : CVE-2024-57889
Mitre link : CVE-2024-57889
CVE.ORG link : CVE-2024-57889
JSON object : View
Improper Locking