{"id":"CVE-2024-42271","url":"https://www.cyber-defence.io/tools/cve/CVE-2024-42271","generatedAt":"2026-10-27T23:58:22.146Z","title":"In the Linux kernel, the following vulnerability has been resolved: net/iucv: fix use after free in iucv_sock_close() iucv_sever_path() is called from process context and from bh context. iucv->path is used as indicator whether somebody else is taking…","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/iucv: fix use after free in iucv_sock_close()\n\niucv_sever_path() is called from process context and from bh context.\niucv->path is used as indicator whether somebody else is taking care of\nsevering the path (or it is already removed / never existed).\nThis needs to be done with atomic compare and swap, otherwise there is a\nsmall window where iucv_sock_close() will try to work with a path that has\nalready been severed and freed by iucv_callback_connrej() called by\niucv_tasklet_fn().\n\nExample:\n[452744.123844] Call Trace:\n[452744.123845] ([<0000001e87f03880>] 0x1e87f03880)\n[452744.123966]  [<00000000d593001e>] iucv_path_sever+0x96/0x138\n[452744.124330]  [<000003ff801ddbca>] iucv_sever_path+0xc2/0xd0 [af_iucv]\n[452744.124336]  [<000003ff801e01b6>] iucv_sock_close+0xa6/0x310 [af_iucv]\n[452744.124341]  [<000003ff801e08cc>] iucv_sock_release+0x3c/0xd0 [af_iucv]\n[452744.124345]  [<00000000d574794e>] __sock_release+0x5e/0xe8\n[452744.124815]  [<00000000d5747a0c>] sock_close+0x34/0x48\n[452744.124820]  [<00000000d5421642>] __fput+0xba/0x268\n[452744.124826]  [<00000000d51b382c>] task_work_run+0xbc/0xf0\n[452744.124832]  [<00000000d5145710>] do_notify_resume+0x88/0x90\n[452744.124841]  [<00000000d5978096>] system_call+0xe2/0x2c8\n[452744.125319] Last Breaking-Event-Address:\n[452744.125321]  [<00000000d5930018>] iucv_path_sever+0x90/0x138\n[452744.125324]\n[452744.125325] Kernel panic - not syncing: Fatal exception in interrupt\n\nNote that bh_lock_sock() is not serializing the tasklet context against\nprocess context, because the check for sock_owned_by_user() and\ncorresponding handling is missing.\n\nIdeas for a future clean-up patch:\nA) Correct usage of bh_lock_sock() in tasklet context, as described in\nRe-enqueue, if needed. This may require adding return values to the\ntasklet functions and thus changes to all users of iucv.\n\nB) Change iucv tasklet into worker and use only lock_sock() in af_iucv.","published":"2024-08-17T09:15:08.000Z","lastModified":"2026-08-04T11:19:44.000Z","status":"Modified","sourceIdentifier":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","cvss":{"version":"3.1","score":7.8,"severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"},"cwe":["CWE-416"],"affected":["linux/linux kernel"],"epss":{"score":0.00235,"percentile":0.14341,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.24%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://git.kernel.org/stable/c/01437282fd3904810603f3dc98d2cac6b8b6fc84","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/37652fbef9809411cea55ea5fa1a170e299efcd0","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/69620522c48ce8215e5eb55ffbab8cafee8f407d","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/84f40b46787ecb67c7ad08a5bb1376141fa10c01","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/8b424c9e44111c5a76f41c6b741f8d4c4179d876","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/ac758e1f663fe9bc64f6b47212a2aa18697524f5","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/c65f72eec60a34ace031426e04e9aff8e5f04895","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/f558120cd709682b739207b48cf7479fd9568431","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html","source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2024-42271","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}