FKIE_CVE-2026-45994

Vulnerability from fkie_nvd - Published: 2026-05-27 14:17 - Updated: 2026-05-27 14:48
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved: ibmasm: fix OOB reads in command_file_write due to missing size checks The command_file_write() handler allocates a kernel buffer of exactly count bytes and copies user data into it, but does not validate the buffer against the dot command protocol before passing it to get_dot_command_size() and get_dot_command_timeout(). Since both the allocation size (count) and the header fields (command_size, data_size) are independently user-controlled, an attacker can cause get_dot_command_size() to return a value exceeding the allocation, triggering OOB reads in get_dot_command_timeout() and an out-of-bounds memcpy_toio() that leaks kernel heap memory to the service processor. Fix with two guards: reject writes smaller than sizeof(struct dot_command_header) before allocation, then after copying user data reject commands where the buffer is smaller than the total size declared by the header (sizeof(header) + command_size + data_size). This ensures all subsequent header and payload field accesses stay within the buffer.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/0eb09f737428e482a32a2e31e5e223f2b35a71d3
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/a672682d39dd34e2b5ba4feb436723bed65125ff
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/aefc1a97da17d8309974690c8a03e439a91ebb1c
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/d0fb4d1dc43f8d5179917a2daaa82680993d4cdf
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/ee5737891464030a189837467df3b81a273718ad
Impacted products
Vendor Product Version
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{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nibmasm: fix OOB reads in command_file_write due to missing size checks\n\nThe command_file_write() handler allocates a kernel buffer of exactly\ncount bytes and copies user data into it, but does not validate the\nbuffer against the dot command protocol before passing it to\nget_dot_command_size() and get_dot_command_timeout().\n\nSince both the allocation size (count) and the header fields (command_size,\ndata_size) are independently user-controlled, an attacker can cause\nget_dot_command_size() to return a value exceeding the allocation,\ntriggering OOB reads in get_dot_command_timeout() and an out-of-bounds\nmemcpy_toio() that leaks kernel heap memory to the service processor.\n\nFix with two guards: reject writes smaller than sizeof(struct\ndot_command_header) before allocation, then after copying user data\nreject commands where the buffer is smaller than the total size declared\nby the header (sizeof(header) + command_size + data_size). This ensures\nall subsequent header and payload field accesses stay within the buffer."
    }
  ],
  "id": "CVE-2026-45994",
  "lastModified": "2026-05-27T14:48:03.013",
  "metrics": {},
  "published": "2026-05-27T14:17:16.970",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/0eb09f737428e482a32a2e31e5e223f2b35a71d3"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/a672682d39dd34e2b5ba4feb436723bed65125ff"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/aefc1a97da17d8309974690c8a03e439a91ebb1c"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/d0fb4d1dc43f8d5179917a2daaa82680993d4cdf"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/ee5737891464030a189837467df3b81a273718ad"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Awaiting Analysis"
}


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