{"id":"CVE-2025-38449","url":"https://www.cyber-defence.io/tools/cve/CVE-2025-38449","generatedAt":"2026-10-28T04:43:06.534Z","title":"In the Linux kernel, the following vulnerability has been resolved: drm/gem: Acquire references on GEM handles for framebuffers A GEM handle can be released while the GEM buffer object is attached to a DRM framebuffer.","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/gem: Acquire references on GEM handles for framebuffers\n\nA GEM handle can be released while the GEM buffer object is attached\nto a DRM framebuffer. This leads to the release of the dma-buf backing\nthe buffer object, if any. [1] Trying to use the framebuffer in further\nmode-setting operations leads to a segmentation fault. Most easily\nhappens with driver that use shadow planes for vmap-ing the dma-buf\nduring a page flip. An example is shown below.\n\n[  156.791968] ------------[ cut here ]------------\n[  156.796830] WARNING: CPU: 2 PID: 2255 at drivers/dma-buf/dma-buf.c:1527 dma_buf_vmap+0x224/0x430\n[...]\n[  156.942028] RIP: 0010:dma_buf_vmap+0x224/0x430\n[  157.043420] Call Trace:\n[  157.045898]  <TASK>\n[  157.048030]  ? show_trace_log_lvl+0x1af/0x2c0\n[  157.052436]  ? show_trace_log_lvl+0x1af/0x2c0\n[  157.056836]  ? show_trace_log_lvl+0x1af/0x2c0\n[  157.061253]  ? drm_gem_shmem_vmap+0x74/0x710\n[  157.065567]  ? dma_buf_vmap+0x224/0x430\n[  157.069446]  ? __warn.cold+0x58/0xe4\n[  157.073061]  ? dma_buf_vmap+0x224/0x430\n[  157.077111]  ? report_bug+0x1dd/0x390\n[  157.080842]  ? handle_bug+0x5e/0xa0\n[  157.084389]  ? exc_invalid_op+0x14/0x50\n[  157.088291]  ? asm_exc_invalid_op+0x16/0x20\n[  157.092548]  ? dma_buf_vmap+0x224/0x430\n[  157.096663]  ? dma_resv_get_singleton+0x6d/0x230\n[  157.101341]  ? __pfx_dma_buf_vmap+0x10/0x10\n[  157.105588]  ? __pfx_dma_resv_get_singleton+0x10/0x10\n[  157.110697]  drm_gem_shmem_vmap+0x74/0x710\n[  157.114866]  drm_gem_vmap+0xa9/0x1b0\n[  157.118763]  drm_gem_vmap_unlocked+0x46/0xa0\n[  157.123086]  drm_gem_fb_vmap+0xab/0x300\n[  157.126979]  drm_atomic_helper_prepare_planes.part.0+0x487/0xb10\n[  157.133032]  ? lockdep_init_map_type+0x19d/0x880\n[  157.137701]  drm_atomic_helper_commit+0x13d/0x2e0\n[  157.142671]  ? drm_atomic_nonblocking_commit+0xa0/0x180\n[  157.147988]  drm_mode_atomic_ioctl+0x766/0xe40\n[...]\n[  157.346424] ---[ end trace 0000000000000000 ]---\n\nAcquiring GEM handles for the framebuffer's GEM buffer objects prevents\nthis from happening. The framebuffer's cleanup later puts the handle\nreferences.\n\nCommit 1a148af06000 (\"drm/gem-shmem: Use dma_buf from GEM object\ninstance\") triggers the segmentation fault easily by using the dma-buf\nfield more widely. The underlying issue with reference counting has\nbeen present before.\n\nv2:\n- acquire the handle instead of the BO (Christian)\n- fix comment style (Christian)\n- drop the Fixes tag (Christian)\n- rename err_ gotos\n- add missing Link tag","published":"2025-07-25T16:15:30.000Z","lastModified":"2026-10-15T22:18:41.000Z","status":"Modified","sourceIdentifier":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","cvss":{"version":"3.1","score":5.5,"severity":"MEDIUM","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"},"cwe":["CWE-416"],"affected":["linux/linux kernel"],"epss":{"score":0.00188,"percentile":0.08305,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.19%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"https://git.kernel.org/stable/c/08480e285c6a82ce689008d643e4a51db0aaef8b","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/3cf520d9860d4ec9f7f32068825da31f18dd3f25","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/5307dce878d4126e1b375587318955bd019c3741","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/cb4c956a15f8b7f870649454771fc3761f504b5f","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2025-38449","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}