{ "schema_version": "1.6.1", "id": "RPI-CVE-2024-36890", "modified": "2026-10-09T11:39:44Z", "upstream": [ "CVE-2024-36890" ], "published": "2024-05-30T15:29:45Z", "summary": "mm/slab: make __free(kfree) accept error pointers", "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/slab: make __free(kfree) accept error pointers\n\nCurrently, if an automatically freed allocation is an error pointer that\nwill lead to a crash. An example of this is in wm831x_gpio_dbg_show().\n\n 171\tchar *label __free(kfree) = gpiochip_dup_line_label(chip, i);\n 172\tif (IS_ERR(label)) {\n 173\t\tdev_err(wm831x->dev, \"Failed to duplicate label\\n\");\n 174\t\tcontinue;\n 175 }\n\nThe auto clean up function should check for error pointers as well,\notherwise we're going to keep hitting issues like this.", "severity": [ { "type": "CVSS_V3", "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H" } ], "affected": [ { "package": { "ecosystem": "Raspberry Pi OS:12", "name": "linux" }, "versions": [ "1:6.6.20-1+rpt1", "1:6.6.28-1+rpt1" ], "ecosystem_specific": { "binaries": [ { "binary_name": "linux-image-6.6.20+rpt-rpi-2712", "binary_version": "1:6.6.20-1+rpt1" }, { "binary_name": "linux-image-6.6.20+rpt-rpi-v6", "binary_version": "1:6.6.20-1+rpt1" }, { "binary_name": "linux-image-6.6.20+rpt-rpi-v7", "binary_version": "1:6.6.20-1+rpt1" }, { "binary_name": "linux-image-6.6.20+rpt-rpi-v7l", "binary_version": "1:6.6.20-1+rpt1" }, { "binary_name": "linux-image-6.6.20+rpt-rpi-v8", "binary_version": "1:6.6.20-1+rpt1" }, { "binary_name": "linux-image-6.6.28+rpt-rpi-2712", "binary_version": "1:6.6.28-1+rpt1" }, { "binary_name": "linux-image-6.6.28+rpt-rpi-v6", "binary_version": "1:6.6.28-1+rpt1" }, { "binary_name": "linux-image-6.6.28+rpt-rpi-v7", "binary_version": "1:6.6.28-1+rpt1" }, { "binary_name": "linux-image-6.6.28+rpt-rpi-v7l", "binary_version": "1:6.6.28-1+rpt1" }, { "binary_name": "linux-image-6.6.28+rpt-rpi-v8", "binary_version": "1:6.6.28-1+rpt1" } ] }, "database_specific": { "per_version": { "1:6.6.20-1+rpt1": { "linux_commit": "6f16847710cc0502450788b9f12f0a14d3429668", "upstream_version": "6.6.20", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.6.31" }, "1:6.6.28-1+rpt1": { "linux_commit": "0c341f47adc3578cd5f817aa20ee2b7f9ae6b23e", "upstream_version": "6.6.28", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.6.31" } } } } ], "references": [ { "type": "ADVISORY", "url": "https://www.cve.org/CVERecord?id=CVE-2024-36890" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/edca32f87329d6e341d2143a3b58ec254e8f6b88" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/946771c2a2b1150f9b7286feadc3aa1e15a1eb16" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/9f6eb0ab4f95240589ee85fd9886a944cd3645b2" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/ac6cf3ce9b7d12acb7b528248df5f87caa25fcdc" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/79cbe0be6c0317b215ddd8bd3e32f0afdac48543" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/cd7eb8f83fcf258f71e293f7fc52a70be8ed0128" } ], "database_specific": { "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git", "upstream_modified": "2026-08-05T11:52:36Z", "severity": { "source": "kernel CNA", "cvss_v3_score": 7.8, "cvss_v3_severity": "High", "scenario": "AV:L - The vulnerable cleanup handler is reached by a local `read()` of the debugfs files `/sys/kernel/debug/gpio` or `/sys/kernel/debug/pinctrl/*/pins`, which dispatch to the affected `dbg_show` callbacks. There is no network or remote path into any `__free(kfree)` site that can receive an error pointer.\nAC:L - Both sides of the trigger are attacker-controlled: the attacker drives system memory pressure to make `kstrdup()` in `gpiochip_dup_line_label()` return `ERR_PTR(-ENOMEM)` while repeatedly reading the debugfs file in a loop, and the resulting bad pointer value is fixed and deterministic rather than layout-dependent.\nPR:L - The kernel creates the gpio debugfs entry mode 0444 under a 0755 debugfs root, so on the many embedded, Android and industrial images that mount debugfs permissively an ordinary unprivileged local account can read it; no capability check exists on the path.\nUI:N - The attacker performs the debugfs read and the memory-pressure generation entirely on their own; no victim process, mount, or administrator action is required.\nS:U - The corruption is confined to the kernel's own slab allocator and page refcounts within the same security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - `kfree()` resolves the error pointer to a real populated `struct page` and either drops a refcount on an unrelated live page or splices a wild pointer onto a live slab freelist, so a subsequent allocation can hand out a pointer aliasing arbitrary kernel memory and disclose its contents.\nI:H - The same slab freelist poisoning gives a controlled kernel write when the wild pointer is later returned by `kmalloc()` and written to, and `folio_put()` on an in-use folio yields a page-level use-after-free \u2014 both are standard primitives for control-flow hijack.\nA:H - In the common case `virt_to_folio()` on `ERR_PTR(-ENOMEM)` dereferences bogus page metadata and the subsequent free corrupts allocator state, producing an immediate oops or a later panic, and it can be re-triggered on every read of the debugfs file." } } }