{"cve":"CVE-2022-50202","nvd":{"published":"2025-06-18T11:15:50.923","modified":"2026-06-17T05:22:58.000","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nPM: hibernate: defer device probing when resuming from hibernation\n\nsyzbot is reporting hung task at misc_open() [1], for there is a race\nwindow of AB-BA deadlock which involves probe_count variable. Currently\nwait_for_device_probe() from snapshot_open() from misc_open() can sleep\nforever with misc_mtx held if probe_count cannot become 0.\n\nWhen a device is probed by hub_event() work function, probe_count is\nincremented before the probe function starts, and probe_count is\ndecremented after the probe function completed.\n\nThere are three cases that can prevent probe_count from dropping to 0.\n\n  (a) A device being probed stopped responding (i.e. broken/malicious\n      hardware).\n\n  (b) A process emulating a USB device using /dev/raw-gadget interface\n      stopped responding for some reason.\n\n  (c) New device probe requests keeps coming in before existing device\n      probe requests complete.\n\nThe phenomenon syzbot is reporting is (b). A process which is holding\nsystem_transition_mutex and misc_mtx is waiting for probe_count to become\n0 inside wait_for_device_probe(), but the probe function which is called\n from hub_event() work function is waiting for the processes which are\nblocked at mutex_lock(&misc_mtx) to respond via /dev/raw-gadget interface.\n\nThis patch mitigates (b) by deferring wait_for_device_probe() from\nsnapshot_open() to snapshot_write() and snapshot_ioctl(). Please note that\nthe possibility of (b) remains as long as any thread which is emulating a\nUSB device via /dev/raw-gadget interface can be blocked by uninterruptible\nblocking operations (e.g. mutex_lock()).\n\nPlease also note that (a) and (c) are not addressed. Regarding (c), we\nshould change the code to wait for only one device which contains the\nimage for resuming from hibernation. I don't know how to address (a), for\nuse of timeout for wait_for_device_probe() might result in loss of user\ndata in the image. Maybe we should require the userland to wait for the\nimage device before opening /dev/snapshot interface.","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":[],"references":["https://git.kernel.org/stable/c/003a456ae6f70bb97e436e02fc5105be577c1570","https://git.kernel.org/stable/c/2f0e18e0db42f4f8bc87d3d98333680065ceeff8","https://git.kernel.org/stable/c/3c48d3067eaf878642276f053575a5c642600a50","https://git.kernel.org/stable/c/5a283b59bce72c05c60e9f0fa92a28b5b850d8bb","https://git.kernel.org/stable/c/8386c414e27caba8501119948e9551e52b527f59"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:03:23.287444849+00:00"},"epss":{"cve":"CVE-2022-50202","score":0.00253,"percentile":0.16891,"date":"2026-10-31"},"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."]}