{"cve":"CVE-2024-26935","nvd":{"published":"2024-05-01T06:15:08.240","modified":"2026-10-15T01:17:32.727","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nscsi: core: Fix unremoved procfs host directory regression\n\nCommit fc663711b944 (\"scsi: core: Remove the /proc/scsi/${proc_name}\ndirectory earlier\") fixed a bug related to modules loading/unloading, by\nadding a call to scsi_proc_hostdir_rm() on scsi_remove_host(). But that led\nto a potential duplicate call to the hostdir_rm() routine, since it's also\ncalled from scsi_host_dev_release(). That triggered a regression report,\nwhich was then fixed by commit be03df3d4bfe (\"scsi: core: Fix a procfs host\ndirectory removal regression\"). The fix just dropped the hostdir_rm() call\nfrom dev_release().\n\nBut it happens that this proc directory is created on scsi_host_alloc(),\nand that function \"pairs\" with scsi_host_dev_release(), while\nscsi_remove_host() pairs with scsi_add_host(). In other words, it seems the\nreason for removing the proc directory on dev_release() was meant to cover\ncases in which a SCSI host structure was allocated, but the call to\nscsi_add_host() didn't happen. And that pattern happens to exist in some\nerror paths, for example.\n\nSyzkaller causes that by using USB raw gadget device, error'ing on\nusb-storage driver, at usb_stor_probe2(). By checking that path, we can see\nthat the BadDevice label leads to a scsi_host_put() after a SCSI host\nallocation, but there's no call to scsi_add_host() in such path. That leads\nto messages like this in dmesg (and a leak of the SCSI host proc\nstructure):\n\nusb-storage 4-1:87.51: USB Mass Storage device detected\nproc_dir_entry 'scsi/usb-storage' already registered\nWARNING: CPU: 1 PID: 3519 at fs/proc/generic.c:377 proc_register+0x347/0x4e0 fs/proc/generic.c:376\n\nThe proper fix seems to still call scsi_proc_hostdir_rm() on dev_release(),\nbut guard that with the state check for SHOST_CREATED; there is even a\ncomment in scsi_host_dev_release() detailing that: such conditional is\nmeant for cases where the SCSI host was allocated but there was no calls to\n{add,remove}_host(), like the usb-storage case.\n\nThis is what we propose here and with that, the error path of usb-storage\ndoes not trigger the warning anymore.","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/0053f15d50d50c9312d8ab9c11e2e405812dfcac","https://git.kernel.org/stable/c/3678cf67ff7136db1dd3bf63c361650db5d92889","https://git.kernel.org/stable/c/5c2386ba80e779a92ec3bb64ccadbedd88f779b1","https://git.kernel.org/stable/c/cea234bb214b17d004dfdccce4491e6ff57c96ee","https://git.kernel.org/stable/c/d4c34782b6d7b1e68d18d9549451b19433bd4c6c"],"products":["debian:debian_linux","linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:49:08.435428910+00:00"},"epss":{"cve":"CVE-2024-26935","score":0.00242,"percentile":0.15223,"date":"2026-10-25"},"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."]}