GHSA-JRV4-9P26-4849
Vulnerability from github – Published: 2026-07-19 12:30 – Updated: 2026-07-20 15:31In the Linux kernel, the following vulnerability has been resolved:
fbdev: omap2: fix use-after-free in omapfb_mmap
omapfb_mmap() has a race condition with OMAPFB_SETUP_PLANE ioctl that can lead to use-after-free:
The fb_mmap() entry point holds mm_lock but not lock (fb_info->lock), while ioctl handlers like OMAPFB_SETUP_PLANE hold lock but not mm_lock. This allows concurrent execution.
In omapfb_mmap(): 1. rg = omapfb_get_mem_region(ofbi->region); // Get old region ref 2. start = omapfb_get_region_paddr(ofbi); // Read from NEW region 3. len = fix->smem_len; // Read from NEW region 4. vm_iomap_memory(vma, start, len); // Map NEW region memory 5. atomic_inc(&rg->map_count); // Increment OLD region!
Concurrently, OMAPFB_SETUP_PLANE can: - Reassign ofbi->region = new_rg - Update fix->smem_len - OMAPFB_SETUP_MEM then checks NEW region's map_count (0!) and frees it
This leaves userspace with a mapping to freed physical memory.
The fix is to read all required values (start, len) from the same region reference (rg) that will have its map_count incremented, preventing the region from being freed while still mapped.
{
"affected": [],
"aliases": [
"CVE-2026-53401"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-07-19T12:16:51Z",
"severity": "HIGH"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nfbdev: omap2: fix use-after-free in omapfb_mmap\n\nomapfb_mmap() has a race condition with OMAPFB_SETUP_PLANE ioctl that\ncan lead to use-after-free:\n\nThe fb_mmap() entry point holds mm_lock but not lock (fb_info-\u003elock),\nwhile ioctl handlers like OMAPFB_SETUP_PLANE hold lock but not mm_lock.\nThis allows concurrent execution.\n\nIn omapfb_mmap():\n1. rg = omapfb_get_mem_region(ofbi-\u003eregion); // Get old region ref\n2. start = omapfb_get_region_paddr(ofbi); // Read from NEW region\n3. len = fix-\u003esmem_len; // Read from NEW region\n4. vm_iomap_memory(vma, start, len); // Map NEW region memory\n5. atomic_inc(\u0026rg-\u003emap_count); // Increment OLD region!\n\nConcurrently, OMAPFB_SETUP_PLANE can:\n- Reassign ofbi-\u003eregion = new_rg\n- Update fix-\u003esmem_len\n- OMAPFB_SETUP_MEM then checks NEW region\u0027s map_count (0!) and frees it\n\nThis leaves userspace with a mapping to freed physical memory.\n\nThe fix is to read all required values (start, len) from the same\nregion reference (rg) that will have its map_count incremented,\npreventing the region from being freed while still mapped.",
"id": "GHSA-jrv4-9p26-4849",
"modified": "2026-07-20T15:31:45Z",
"published": "2026-07-19T12:30:23Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-53401"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/6eb6ebcc8590007ad59ddccc8b5f9201655b33f8"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/7958e67375aa111522086286bba13cfc0816ce8d"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
Sightings
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Nomenclature
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- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.