{"id":"CVE-2024-49870","summary":"cachefiles: fix dentry leak in cachefiles_open_file()","details":"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-\u003ei_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-\u003ei_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 \u003cTASK\u003e\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.","modified":"2026-04-02T12:21:03.706762Z","published":"2024-10-21T18:01:12.048Z","related":["MGASA-2024-0344","MGASA-2024-0345","SUSE-SU-2024:3984-1","SUSE-SU-2024:3986-1","SUSE-SU-2024:4315-1","SUSE-SU-2024:4318-1","SUSE-SU-2024:4364-1","SUSE-SU-2024:4376-1","SUSE-SU-2024:4387-1","SUSE-SU-2025:20163-1","SUSE-SU-2025:20164-1","SUSE-SU-2025:20246-1","SUSE-SU-2025:20247-1","USN-7276-1","USN-7277-1","openSUSE-SU-2024:14500-1","openSUSE-SU-2025:14705-1"],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/49xxx/CVE-2024-49870.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/7fa2382f97421978514a419c93054eca69f5247b"},{"type":"WEB","url":"https://git.kernel.org/stable/c/c7d10fa7d7691558ff967668494672415f5fa151"},{"type":"WEB","url":"https://git.kernel.org/stable/c/d32ff64c872d7e08e893c32ba6a2374583444410"},{"type":"WEB","url":"https://git.kernel.org/stable/c/da6ef2dffe6056aad3435e6cf7c6471c2a62187c"},{"type":"WEB","url":"https://git.kernel.org/stable/c/e4a28489b310339b2b8187bec0a437709be551c1"},{"type":"WEB","url":"https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/49xxx/CVE-2024-49870.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2024-49870"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"1f08c925e7a38002bde509e66f6f891468848511"},{"fixed":"d32ff64c872d7e08e893c32ba6a2374583444410"},{"fixed":"c7d10fa7d7691558ff967668494672415f5fa151"},{"fixed":"e4a28489b310339b2b8187bec0a437709be551c1"},{"fixed":"7fa2382f97421978514a419c93054eca69f5247b"},{"fixed":"da6ef2dffe6056aad3435e6cf7c6471c2a62187c"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2024-49870.json"}}],"schema_version":"1.7.5"}