{
   "containers": {
      "cna": {
         "providerMetadata": {
            "orgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038"
         },
         "descriptions": [
            {
               "lang": "en",
               "value": "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->done)\n\n            cachefiles_daemon_read\n             cachefiles_ondemand_daemon_read\n              REQ_A = cachefiles_ondemand_select_req\n              msg->object_id = req->object->ondemand->ondemand_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->reqs, id)\n               complete(&REQ_A->done)\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->object->ondemand->ondemand_id\n                                     // object UAF !!!\n\nWhen we see the request within xa_lock, req->object must not have been\nfreed yet, so grab the reference count of object before xa_unlock to\navoid the above issue."
            }
         ],
         "affected": [
            {
               "product": "Linux",
               "vendor": "Linux",
               "defaultStatus": "unaffected",
               "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
               "programFiles": [
                  "fs/cachefiles/ondemand.c",
                  "include/trace/events/cachefiles.h"
               ],
               "versions": [
                  {
                     "version": "f17443d52d80",
                     "lessThan": "cb55625f8eb9",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "f740fd943bb1",
                     "lessThan": "3958679c4915",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "0a7e54c1959c",
                     "lessThan": "93064676a282",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "0a7e54c1959c",
                     "lessThan": "da4a82741606",
                     "status": "affected",
                     "versionType": "git"
                  }
               ]
            },
            {
               "product": "Linux",
               "vendor": "Linux",
               "defaultStatus": "affected",
               "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
               "programFiles": [
                  "fs/cachefiles/ondemand.c",
                  "include/trace/events/cachefiles.h"
               ],
               "versions": [
                  {
                     "version": "6.8",
                     "status": "affected"
                  },
                  {
                     "version": "0",
                     "lessThan": "6.8",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "6.9.6",
                     "lessThanOrEqual": "6.9.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "6.10",
                     "lessThanOrEqual": "*",
                     "status": "unaffected",
                     "versionType": "original_commit_for_fix"
                  }
               ]
            }
         ],
         "references": [
            {
               "url": "https://git.kernel.org/stable/c/cb55625f8eb9d2de8be4da0c4580d48cbb32058e"
            },
            {
               "url": "https://git.kernel.org/stable/c/3958679c49152391209b32be3357193300a51abd"
            },
            {
               "url": "https://git.kernel.org/stable/c/93064676a2820420a2d37d7c8289f277fe20793d"
            },
            {
               "url": "https://git.kernel.org/stable/c/da4a827416066191aafeeccee50a8836a826ba10"
            }
         ],
         "title": "cachefiles: fix slab-use-after-free in cachefiles_ondemand_daemon_read()",
         "x_generator": {
            "engine": "bippy-c9c4e1df01b2"
         }
      }
   },
   "cveMetadata": {
      "assignerOrgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038",
      "cveID": "CVE-2024-39510",
      "requesterUserId": "gregkh@kernel.org",
      "serial": "1",
      "state": "PUBLISHED"
   },
   "dataType": "CVE_RECORD",
   "dataVersion": "5.0"
}