{"uuid": "8853c43e-1e6c-4121-891a-a14ba65ce91a", "vulnerability_lookup_origin": "1a89b78e-f703-45f3-bb86-59eb712668bd", "author": "2a075640-a300-48a4-bb44-bc6130783b9b", "vulnerability": "CVE-2025-21709", "type": "published-proof-of-concept", "source": "https://t.me/DarkWebInformer_CVEAlerts/5644", "content": "\ud83d\udd17 DarkWebInformer.com - Cyber Threat Intelligence\n\ud83d\udccc CVE ID: CVE-2025-21709\n\ud83d\udd25 CVSS Score: N/A\n\ud83d\udd39 Description: In the Linux kernel, the following vulnerability has been resolved:\n\nkernel: be more careful about dup_mmap() failures and uprobe registering\n\nIf a memory allocation fails during dup_mmap(), the maple tree can be left\nin an unsafe state for other iterators besides the exit path.  All the\nlocks are dropped before the exit_mmap() call (in mm/mmap.c), but the\nincomplete mm_struct can be reached through (at least) the rmap finding\nthe vmas which have a pointer back to the mm_struct.\n\nUp to this point, there have been no issues with being able to find an\nmm_struct that was only partially initialised.  Syzbot was able to make\nthe incomplete mm_struct fail with recent forking changes, so it has been\nproven unsafe to use the mm_struct that hasn't been initialised, as\nreferenced in the link below.\n\nAlthough 8ac662f5da19f (\"fork: avoid inappropriate uprobe access to\ninvalid mm\") fixed the uprobe access, it does not completely remove the\nrace.\n\nThis patch sets the MMF_OOM_SKIP to avoid the iteration of the vmas on the\noom side (even though this is extremely unlikely to be selected as an oom\nvictim in the race window), and sets MMF_UNSTABLE to avoid other potential\nusers from using a partially initialised mm_struct.\n\nWhen registering vmas for uprobe, skip the vmas in an mm that is marked\nunstable.  Modifying a vma in an unstable mm may cause issues if the mm\nisn't fully initialised.\n\ud83d\udccf Published: 2025-02-27T02:07:22.452Z\n\ud83d\udccf Modified: 2025-02-27T02:07:22.452Z\n\ud83d\udd17 References:\n1. https://git.kernel.org/stable/c/da139948aeda677ac09cc0e7d837f8a314de7d55\n2. https://git.kernel.org/stable/c/64c37e134b120fb462fb4a80694bfb8e7be77b14", "creation_timestamp": "2025-02-27T02:25:32.000000Z"}