{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-74733", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-15T05:44:03.930Z", "datePublished": "2026-08-22T15:33:21.579Z", "dateUpdated": "2026-10-16T19:16:12.549Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-15T10:09:27.988Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ngpio: pca953x: fix pca953x_irq_bus_sync_unlock regmap lock\n\nLocking is disabled in the regmap config as this driver uses its own\nlock. This means that all calls to regmap functions (read or write) must\nhold the i2c_lock. The function pca953x_irq_bus_sync_unlock() did not do\nthis, and it was therefore possible that multiple threads could cause an\nincorrect register to be read/written.\n\nA previous patch partly fixed this, but only protected the write to the\ninterrupt mask register, and not the read from the direction register." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The vulnerable pca953x_irq_bus_sync_unlock() path is reached only through local kernel interfaces—GPIO chardev ioctls (GPIO_V2_GET_LINE_IOCTL, GPIO_V2_LINE_SET_CONFIG_IOCTL, GPIO_V2_LINE_SET_VALUES_IOCTL), legacy sysfs GPIO, or concurrent in-kernel GPIO/IRQ ops—not via any network or physical bus-facing attack surface.\nAC:L - An attacker drives both racing sides directly: one thread loops IRQ edge-detection setup/teardown (request_irq → irq_bus_sync_unlock) while another hammers GPIO value/direction writes holding i2c_lock; the original report reproduced the race ~1 in 1000 boots, so deliberate concurrency wins reliably.\nPR:L - Exploitation requires an open file descriptor on /dev/gpiochipN or sysfs GPIO access; on embedded, industrial, medical, and automotive boards using pca953x expanders, udev routinely grants gpio group membership to unprivileged local users.\nUI:N - No victim interaction is required—the attacker performs all GPIO ioctl and IRQ configuration steps in its own threads without needing another user to mount, open, or configure devices.\nS:U - Corruption is confined to the kernel and the same on-board I2C GPIO expander; it does not cross VM, container, IOMMU, or other security-boundary scopes into a different authority.\nC:H - With regmap disable_locking=true, the unprotected pca953x_read_regs() direction read races locked regmap paths, corrupting the maple regcache and returning data from the wrong register—yielding kernel heap UAF read and unintended register-state disclosure.\nI:H - Racing regmap transactions write interrupt-latch/direction data into wrong expander registers (documented output-register corruption), arbitrarily toggling safety-critical GPIO outputs; concurrent unsynchronized regcache writes provide a heap corruption/write primitive.\nA:H - Concurrent regcache maple-tree corruption from unsynchronized regmap access can trigger kernel oops/panic via double-free; miswritten interrupt masks or direction registers can wedge expander IRQ handling and GPIO consumers in a persistent denial-of-service." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/gpio/gpio-pca953x.c" ], "versions": [ { "version": "bfc6444b57dc7186b6acc964705d7516cbaf3904", "lessThan": "bf3f37c2d40b51deb79aea910f28999d7c8c6b5a", "status": "affected", "versionType": "git" }, { "version": "bfc6444b57dc7186b6acc964705d7516cbaf3904", "lessThan": "e6a2f5f845f50b0c4299bace5111f56d3390a090", "status": "affected", "versionType": "git" }, { "version": "bfc6444b57dc7186b6acc964705d7516cbaf3904", "lessThan": "9dc325327babe7f159e84cbe9380a45342da0585", "status": "affected", "versionType": "git" }, { "version": "58a5c93bd1a6e949267400080f07e57ffe05ec34", "status": "affected", "versionType": "git" }, { "version": "e2ecdddca80dd845df42376e4b0197fe97018ba2", "status": "affected", "versionType": "git" }, { "version": "de7cffa53149c7b48bd1bb29b02390c9f05b7f41", "status": "affected", "versionType": "git" }, { "version": "6.1.101", "lessThan": "6.2", "status": "affected", "versionType": "semver" }, { "version": "6.6.42", "lessThan": "6.7", "status": "affected", "versionType": "semver" }, { "version": "6.9.11", "lessThan": "6.10", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/gpio/gpio-pca953x.c" ], "versions": [ { "version": "6.10", "status": "affected" }, { "version": "0", "lessThan": "6.10", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.57", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.9", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.10", "versionEndExcluding": "6.18.57" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.10", "versionEndExcluding": "7.1.9" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.10", "versionEndExcluding": "7.2" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.1.101" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.6.42" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.9.11" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/bf3f37c2d40b51deb79aea910f28999d7c8c6b5a" }, { "url": "https://git.kernel.org/stable/c/e6a2f5f845f50b0c4299bace5111f56d3390a090" }, { "url": "https://git.kernel.org/stable/c/9dc325327babe7f159e84cbe9380a45342da0585" } ], "title": "gpio: pca953x: fix pca953x_irq_bus_sync_unlock regmap lock", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "id": "CVE-2026-74733", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "total" } ], "version": "2.0.3", "timestamp": "2026-10-16T19:15:53.820928Z" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-16T19:16:12.549Z" } } ] } }