CVE-2026-46022
In the Linux kernel, the following vulnerability has been resolved: misc: ibmasm: fix OOB MMIO read in ibmasm_handle_mouse_interrupt() ibmasm_handle_mouse_interrupt() performs an out-of-bounds MMIO read when the queue reader or writer index from…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.14%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
In the Linux kernel, the following vulnerability has been resolved: misc: ibmasm: fix OOB MMIO read in ibmasm_handle_mouse_interrupt() ibmasm_handle_mouse_interrupt() performs an out-of-bounds MMIO read when the queue reader or writer index from hardware exceeds REMOTE_QUEUE_SIZE (60). A compromised service processor can trigger this by writing an out-of-range value to the reader or writer MMIO register before asserting an interrupt. Since writer is re-read from hardware on every loop iteration, it can also be set to an out-of-range value after the loop has already started. The root cause is that get_queue_reader() and get_queue_writer() return raw readl() values that are passed directly into get_queue_entry(), which computes: queue_begin + reader * sizeof(struct remote_input) with no bounds check. This unchecked MMIO address is then passed to memcpy_fromio(), reading 8 bytes from unintended device registers. For sufficiently large values the address falls outside the PCI BAR mapping entirely, triggering a machine check exception. Fix by checking both indices against REMOTE_QUEUE_SIZE at the top of the loop body, before any call to get_queue_entry(). On an out-of-range value, reset the reader register to 0 via set_queue_reader() before breaking, so that normal queue operation can resume if the corrupted hardware state is transient.
- CVSS 3.1
- 7.1 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
- EPSS
- 0.14% probability · 4th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-125
- Affected
- linux/linux kernel
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/07c4f18b303106e6b24492c12b95d48a4b985841Patch
- https://git.kernel.org/stable/c/1ca75f6b74ec7f685464e5745ecfcf3a76d284e9Patch
- https://git.kernel.org/stable/c/22a16d3eafee92a165c756081587c95850127107Patch
- https://git.kernel.org/stable/c/4b6e6ead556734bdc14024c5f837132b1e7a4b84Patch
- https://git.kernel.org/stable/c/6f6ecc9153df176e956d0664b56f93080b0a45f0Patch
- https://git.kernel.org/stable/c/bac8643486f854dd53af9b23aea7dbbd9b7c1865Patch
- https://git.kernel.org/stable/c/f7e5b4eefd7be3e09f8bd5fee63ed478fd7446abPatch
- https://git.kernel.org/stable/c/fc7e9a74e32299d7e93e178ca482a0b59ef1595bPatch
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.