{"id":"CVE-2025-37779","url":"https://www.cyber-defence.io/tools/cve/CVE-2025-37779","generatedAt":"2026-10-27T23:57:56.256Z","title":"In the Linux kernel, the following vulnerability has been resolved: lib/iov_iter: fix to increase non slab folio refcount When testing EROFS file-backed mount over v9fs on qemu, I encountered a folio UAF issue.","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nlib/iov_iter: fix to increase non slab folio refcount\n\nWhen testing EROFS file-backed mount over v9fs on qemu, I encountered a\nfolio UAF issue.  The page sanity check reports the following call trace. \nThe root cause is that pages in bvec are coalesced across a folio bounary.\nThe refcount of all non-slab folios should be increased to ensure\np9_releas_pages can put them correctly.\n\nBUG: Bad page state in process md5sum  pfn:18300\npage: refcount:0 mapcount:0 mapping:00000000d5ad8e4e index:0x60 pfn:0x18300\nhead: order:0 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0\naops:z_erofs_aops ino:30b0f dentry name(?):\"GoogleExtServicesCn.apk\"\nflags: 0x100000000000041(locked|head|node=0|zone=1)\nraw: 0100000000000041 dead000000000100 dead000000000122 ffff888014b13bd0\nraw: 0000000000000060 0000000000000020 00000000ffffffff 0000000000000000\nhead: 0100000000000041 dead000000000100 dead000000000122 ffff888014b13bd0\nhead: 0000000000000060 0000000000000020 00000000ffffffff 0000000000000000\nhead: 0100000000000000 0000000000000000 ffffffffffffffff 0000000000000000\nhead: 0000000000000010 0000000000000000 00000000ffffffff 0000000000000000\npage dumped because: PAGE_FLAGS_CHECK_AT_FREE flag(s) set\nCall Trace:\n dump_stack_lvl+0x53/0x70\n bad_page+0xd4/0x220\n __free_pages_ok+0x76d/0xf30\n __folio_put+0x230/0x320\n p9_release_pages+0x179/0x1f0\n p9_virtio_zc_request+0xa2a/0x1230\n p9_client_zc_rpc.constprop.0+0x247/0x700\n p9_client_read_once+0x34d/0x810\n p9_client_read+0xf3/0x150\n v9fs_issue_read+0x111/0x360\n netfs_unbuffered_read_iter_locked+0x927/0x1390\n netfs_unbuffered_read_iter+0xa2/0xe0\n vfs_iocb_iter_read+0x2c7/0x460\n erofs_fileio_rq_submit+0x46b/0x5b0\n z_erofs_runqueue+0x1203/0x21e0\n z_erofs_readahead+0x579/0x8b0\n read_pages+0x19f/0xa70\n page_cache_ra_order+0x4ad/0xb80\n filemap_readahead.isra.0+0xe7/0x150\n filemap_get_pages+0x7aa/0x1890\n filemap_read+0x320/0xc80\n vfs_read+0x6c6/0xa30\n ksys_read+0xf9/0x1c0\n do_syscall_64+0x9e/0x1a0\n entry_SYSCALL_64_after_hwframe+0x71/0x79","published":"2025-05-01T14:15:42.000Z","lastModified":"2026-07-30T06:22:20.000Z","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-415"],"affected":["linux/linux kernel"],"epss":{"score":0.00169,"percentile":0.06205,"date":"2026-10-26","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 (0.17%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"https://git.kernel.org/stable/c/770c8d55c42868239c748a3ebc57c9e37755f842","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/d833f21162c4d536d729628f8cf1ee8d4110f2b7","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2025-37779","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."}