{"id":"CVE-2024-39510","summary":"cachefiles: fix slab-use-after-free in cachefiles_ondemand_daemon_read()","details":"In the Linux kernel, the following vulnerability has been resolved:\n\ncachefiles: fix slab-use-after-free in cachefiles_ondemand_daemon_read()\n\nWe got the following issue in a fuzz test of randomly issuing the restore\ncommand:\n\n==================================================================\nBUG: KASAN: slab-use-after-free in cachefiles_ondemand_daemon_read+0xb41/0xb60\nRead of size 8 at addr ffff888122e84088 by task ondemand-04-dae/963\n\nCPU: 13 PID: 963 Comm: ondemand-04-dae Not tainted 6.8.0-dirty #564\nCall Trace:\n kasan_report+0x93/0xc0\n cachefiles_ondemand_daemon_read+0xb41/0xb60\n vfs_read+0x169/0xb50\n ksys_read+0xf5/0x1e0\n\nAllocated by task 116:\n kmem_cache_alloc+0x140/0x3a0\n cachefiles_lookup_cookie+0x140/0xcd0\n fscache_cookie_state_machine+0x43c/0x1230\n [...]\n\nFreed by task 792:\n kmem_cache_free+0xfe/0x390\n cachefiles_put_object+0x241/0x480\n fscache_cookie_state_machine+0x5c8/0x1230\n [...]\n==================================================================\n\nFollowing is the process that triggers the issue:\n\n     mount  |   daemon_thread1    |    daemon_thread2\n------------------------------------------------------------\ncachefiles_withdraw_cookie\n cachefiles_ondemand_clean_object(object)\n  cachefiles_ondemand_send_req\n   REQ_A = kzalloc(sizeof(*req) + data_len)\n   wait_for_completion(&REQ_A-\u003edone)\n\n            cachefiles_daemon_read\n             cachefiles_ondemand_daemon_read\n              REQ_A = cachefiles_ondemand_select_req\n              msg-\u003eobject_id = req-\u003eobject-\u003eondemand-\u003eondemand_id\n                                  ------ restore ------\n                                  cachefiles_ondemand_restore\n                                  xas_for_each(&xas, req, ULONG_MAX)\n                                   xas_set_mark(&xas, CACHEFILES_REQ_NEW)\n\n                                  cachefiles_daemon_read\n                                   cachefiles_ondemand_daemon_read\n                                    REQ_A = cachefiles_ondemand_select_req\n              copy_to_user(_buffer, msg, n)\n               xa_erase(&cache-\u003ereqs, id)\n               complete(&REQ_A-\u003edone)\n              ------ close(fd) ------\n              cachefiles_ondemand_fd_release\n               cachefiles_put_object\n cachefiles_put_object\n  kmem_cache_free(cachefiles_object_jar, object)\n                                    REQ_A-\u003eobject-\u003eondemand-\u003eondemand_id\n                                     // object UAF !!!\n\nWhen we see the request within xa_lock, req-\u003eobject must not have been\nfreed yet, so grab the reference count of object before xa_unlock to\navoid the above issue.","modified":"2026-04-02T12:17:03.409406Z","published":"2024-07-12T12:20:40.901Z","related":["SUSE-SU-2024:3194-1","SUSE-SU-2024:3195-1","SUSE-SU-2024:3383-1","SUSE-SU-2025:20044-1","SUSE-SU-2025:20047-1"],"database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/39xxx/CVE-2024-39510.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/3958679c49152391209b32be3357193300a51abd"},{"type":"WEB","url":"https://git.kernel.org/stable/c/93064676a2820420a2d37d7c8289f277fe20793d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/cb55625f8eb9d2de8be4da0c4580d48cbb32058e"},{"type":"WEB","url":"https://git.kernel.org/stable/c/da4a827416066191aafeeccee50a8836a826ba10"},{"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/2024/39xxx/CVE-2024-39510.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2024-39510"},{"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":"f17443d52d805c9a7fab5e67a4e8b973626fe1cd"},{"fixed":"cb55625f8eb9d2de8be4da0c4580d48cbb32058e"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"f740fd943bb1fbf79b7eaba3c71eb7536f437f51"},{"fixed":"3958679c49152391209b32be3357193300a51abd"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"0a7e54c1959c0feb2de23397ec09c7692364313e"},{"fixed":"93064676a2820420a2d37d7c8289f277fe20793d"},{"fixed":"da4a827416066191aafeeccee50a8836a826ba10"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2024-39510.json"}}],"schema_version":"1.7.5"}