{"cve":"CVE-2024-49870","nvd":{"published":"2024-10-21T18:15:08.413","modified":"2026-06-17T08:00:37.487","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ncachefiles: fix dentry leak in cachefiles_open_file()\n\nA dentry leak may be caused when a lookup cookie and a cull are concurrent:\n\n            P1             |             P2\n-----------------------------------------------------------\ncachefiles_lookup_cookie\n  cachefiles_look_up_object\n    lookup_one_positive_unlocked\n     // get dentry\n                            cachefiles_cull\n                              inode->i_flags |= S_KERNEL_FILE;\n    cachefiles_open_file\n      cachefiles_mark_inode_in_use\n        __cachefiles_mark_inode_in_use\n          can_use = false\n          if (!(inode->i_flags & S_KERNEL_FILE))\n            can_use = true\n\t  return false\n        return false\n        // Returns an error but doesn't put dentry\n\nAfter that the following WARNING will be triggered when the backend folder\nis umounted:\n\n==================================================================\nBUG: Dentry 000000008ad87947{i=7a,n=Dx_1_1.img}  still in use (1) [unmount of ext4 sda]\nWARNING: CPU: 4 PID: 359261 at fs/dcache.c:1767 umount_check+0x5d/0x70\nCPU: 4 PID: 359261 Comm: umount Not tainted 6.6.0-dirty #25\nRIP: 0010:umount_check+0x5d/0x70\nCall Trace:\n <TASK>\n d_walk+0xda/0x2b0\n do_one_tree+0x20/0x40\n shrink_dcache_for_umount+0x2c/0x90\n generic_shutdown_super+0x20/0x160\n kill_block_super+0x1a/0x40\n ext4_kill_sb+0x22/0x40\n deactivate_locked_super+0x35/0x80\n cleanup_mnt+0x104/0x160\n==================================================================\n\nWhether cachefiles_open_file() returns true or false, the reference count\nobtained by lookup_positive_unlocked() in cachefiles_look_up_object()\nshould be released.\n\nTherefore release that reference count in cachefiles_look_up_object() to\nfix the above issue and simplify the code.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-401"],"references":["https://git.kernel.org/stable/c/7fa2382f97421978514a419c93054eca69f5247b","https://git.kernel.org/stable/c/c7d10fa7d7691558ff967668494672415f5fa151","https://git.kernel.org/stable/c/d32ff64c872d7e08e893c32ba6a2374583444410","https://git.kernel.org/stable/c/da6ef2dffe6056aad3435e6cf7c6471c2a62187c","https://git.kernel.org/stable/c/e4a28489b310339b2b8187bec0a437709be551c1"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:56:33.105311382+00:00"},"epss":{"cve":"CVE-2024-49870","score":0.00236,"percentile":0.14608,"date":"2026-11-01"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}