{"id":"CVE-2023-52982","summary":"fscache: Use wait_on_bit() to wait for the freeing of relinquished volume","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nfscache: Use wait_on_bit() to wait for the freeing of relinquished volume\n\nThe freeing of relinquished volume will wake up the pending volume\nacquisition by using wake_up_bit(), however it is mismatched with\nwait_var_event() used in fscache_wait_on_volume_collision() and it will\nnever wake up the waiter in the wait-queue because these two functions\noperate on different wait-queues.\n\nAccording to the implementation in fscache_wait_on_volume_collision(),\nif the wake-up of pending acquisition is delayed longer than 20 seconds\n(e.g., due to the delay of on-demand fd closing), the first\nwait_var_event_timeout() will timeout and the following wait_var_event()\nwill hang forever as shown below:\n\n FS-Cache: Potential volume collision new=00000024 old=00000022\n ......\n INFO: task mount:1148 blocked for more than 122 seconds.\n       Not tainted 6.1.0-rc6+ #1\n task:mount           state:D stack:0     pid:1148  ppid:1\n Call Trace:\n  \u003cTASK\u003e\n  __schedule+0x2f6/0xb80\n  schedule+0x67/0xe0\n  fscache_wait_on_volume_collision.cold+0x80/0x82\n  __fscache_acquire_volume+0x40d/0x4e0\n  erofs_fscache_register_volume+0x51/0xe0 [erofs]\n  erofs_fscache_register_fs+0x19c/0x240 [erofs]\n  erofs_fc_fill_super+0x746/0xaf0 [erofs]\n  vfs_get_super+0x7d/0x100\n  get_tree_nodev+0x16/0x20\n  erofs_fc_get_tree+0x20/0x30 [erofs]\n  vfs_get_tree+0x24/0xb0\n  path_mount+0x2fa/0xa90\n  do_mount+0x7c/0xa0\n  __x64_sys_mount+0x8b/0xe0\n  do_syscall_64+0x30/0x60\n  entry_SYSCALL_64_after_hwframe+0x46/0xb0\n\nConsidering that wake_up_bit() is more selective, so fix it by using\nwait_on_bit() instead of wait_var_event() to wait for the freeing of\nrelinquished volume. In addition because waitqueue_active() is used in\nwake_up_bit() and clear_bit() doesn't imply any memory barrier, use\nclear_and_wake_up_bit() to add the missing memory barrier between\ncursor-\u003eflags and waitqueue_active().","modified":"2026-04-11T12:46:39.127580Z","published":"2025-03-27T16:43:20.735Z","related":["SUSE-SU-2025:01620-1","SUSE-SU-2025:01640-1"],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/52xxx/CVE-2023-52982.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/3be069f42a7b79d3149194f21cdf24bf23864cac"},{"type":"WEB","url":"https://git.kernel.org/stable/c/8226e37d82f43657da34dd770e2b38f20242ada7"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/52xxx/CVE-2023-52982.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2023-52982"},{"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":"62ab63352350e881ae693a8236b35d7d0516c78b"},{"fixed":"3be069f42a7b79d3149194f21cdf24bf23864cac"},{"fixed":"8226e37d82f43657da34dd770e2b38f20242ada7"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2023-52982.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.17.0"},{"fixed":"6.1.11"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2023-52982.json"}}],"schema_version":"1.7.5"}