CVE-2025-38449

{"id": "CVE-2025-38449", "cveTags": [], "metrics": {}, "published": "2025-07-25T16:15:30.443", "references": [{"url": "https://git.kernel.org/stable/c/08480e285c6a82ce689008d643e4a51db0aaef8b", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/3cf520d9860d4ec9f7f32068825da31f18dd3f25", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/5307dce878d4126e1b375587318955bd019c3741", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/cb4c956a15f8b7f870649454771fc3761f504b5f", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "vulnStatus": "Awaiting Analysis", "descriptions": [{"lang": "en", "value": "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"}, {"lang": "es", "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: drm/gem: Adquisici\u00f3n de referencias en manejadores GEM para framebuffers. Un manejador GEM puede liberarse mientras el objeto de b\u00fafer GEM est\u00e1 asociado a un framebuffer DRM. Esto provoca la liberaci\u00f3n del dma-buf que respalda el objeto de b\u00fafer, si lo hay. [1] Intentar usar el framebuffer en otras operaciones de configuraci\u00f3n de modo provoca un fallo de segmentaci\u00f3n. Esto ocurre con mayor frecuencia con controladores que utilizan planos de sombra para vmapear el dma-buf durante un cambio de p\u00e1gina. A continuaci\u00f3n se muestra un ejemplo. [ 156.791968] ------------[ cut here ]------------ [ 156.796830] WARNING: CPU: 2 PID: 2255 at drivers/dma-buf/dma-buf.c:1527 dma_buf_vmap+0x224/0x430 [...] [ 156.942028] RIP: 0010:dma_buf_vmap+0x224/0x430 [ 157.043420] Call Trace: [ 157.045898] [ 157.048030] ? show_trace_log_lvl+0x1af/0x2c0 [ 157.052436] ? show_trace_log_lvl+0x1af/0x2c0 [ 157.056836] ? show_trace_log_lvl+0x1af/0x2c0 [ 157.061253] ? drm_gem_shmem_vmap+0x74/0x710 [ 157.065567] ? dma_buf_vmap+0x224/0x430 [ 157.069446] ? __warn.cold+0x58/0xe4 [ 157.073061] ? dma_buf_vmap+0x224/0x430 [ 157.077111] ? report_bug+0x1dd/0x390 [ 157.080842] ? handle_bug+0x5e/0xa0 [ 157.084389] ? exc_invalid_op+0x14/0x50 [ 157.088291] ? asm_exc_invalid_op+0x16/0x20 [ 157.092548] ? dma_buf_vmap+0x224/0x430 [ 157.096663] ? dma_resv_get_singleton+0x6d/0x230 [ 157.101341] ? __pfx_dma_buf_vmap+0x10/0x10 [ 157.105588] ? __pfx_dma_resv_get_singleton+0x10/0x10 [ 157.110697] drm_gem_shmem_vmap+0x74/0x710 [ 157.114866] drm_gem_vmap+0xa9/0x1b0 [ 157.118763] drm_gem_vmap_unlocked+0x46/0xa0 [ 157.123086] drm_gem_fb_vmap+0xab/0x300 [ 157.126979] drm_atomic_helper_prepare_planes.part.0+0x487/0xb10 [ 157.133032] ? lockdep_init_map_type+0x19d/0x880 [ 157.137701] drm_atomic_helper_commit+0x13d/0x2e0 [ 157.142671] ? drm_atomic_nonblocking_commit+0xa0/0x180 [ 157.147988] drm_mode_atomic_ioctl+0x766/0xe40 [...] [ 157.346424] ---[ end trace 0000000000000000 ]--- Acquiring GEM handles for the framebuffer's GEM buffer objects prevents this from happening. The framebuffer's cleanup later puts the handle references. Commit 1a148af06000 (\"drm/gem-shmem: Use dma_buf from GEM object instance\") triggers the segmentation fault easily by using the dma-buf field more widely. The underlying issue with reference counting has been present before. v2: - acquire the handle instead of the BO (Christian) - fix comment style (Christian) - drop the Fixes tag (Christian) - rename err_ gotos - add missing Link tag"}], "lastModified": "2025-07-29T14:14:55.157", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}