{"id":"CVE-2024-42271","summary":"net/iucv: fix use after free in iucv_sock_close()","details":"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-\u003epath 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] ([\u003c0000001e87f03880\u003e] 0x1e87f03880)\n[452744.123966]  [\u003c00000000d593001e\u003e] iucv_path_sever+0x96/0x138\n[452744.124330]  [\u003c000003ff801ddbca\u003e] iucv_sever_path+0xc2/0xd0 [af_iucv]\n[452744.124336]  [\u003c000003ff801e01b6\u003e] iucv_sock_close+0xa6/0x310 [af_iucv]\n[452744.124341]  [\u003c000003ff801e08cc\u003e] iucv_sock_release+0x3c/0xd0 [af_iucv]\n[452744.124345]  [\u003c00000000d574794e\u003e] __sock_release+0x5e/0xe8\n[452744.124815]  [\u003c00000000d5747a0c\u003e] sock_close+0x34/0x48\n[452744.124820]  [\u003c00000000d5421642\u003e] __fput+0xba/0x268\n[452744.124826]  [\u003c00000000d51b382c\u003e] task_work_run+0xbc/0xf0\n[452744.124832]  [\u003c00000000d5145710\u003e] do_notify_resume+0x88/0x90\n[452744.124841]  [\u003c00000000d5978096\u003e] system_call+0xe2/0x2c8\n[452744.125319] Last Breaking-Event-Address:\n[452744.125321]  [\u003c00000000d5930018\u003e] 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.","modified":"2026-04-16T04:34:54.796747999Z","published":"2024-08-17T08:54:26.048Z","related":["SUSE-SU-2024:3189-1","SUSE-SU-2024:3190-1","SUSE-SU-2024:3194-1","SUSE-SU-2024:3195-1","SUSE-SU-2024:3209-1","SUSE-SU-2024:3225-1","SUSE-SU-2024:3227-1","SUSE-SU-2024:3249-1","SUSE-SU-2024:3251-1","SUSE-SU-2024:3252-1","SUSE-SU-2024:3383-1","SUSE-SU-2024:3408-1","SUSE-SU-2024:3483-1","SUSE-SU-2024:3499-1","SUSE-SU-2025:20044-1","SUSE-SU-2025:20047-1"],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/42xxx/CVE-2024-42271.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/01437282fd3904810603f3dc98d2cac6b8b6fc84"},{"type":"WEB","url":"https://git.kernel.org/stable/c/37652fbef9809411cea55ea5fa1a170e299efcd0"},{"type":"WEB","url":"https://git.kernel.org/stable/c/69620522c48ce8215e5eb55ffbab8cafee8f407d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/84f40b46787ecb67c7ad08a5bb1376141fa10c01"},{"type":"WEB","url":"https://git.kernel.org/stable/c/8b424c9e44111c5a76f41c6b741f8d4c4179d876"},{"type":"WEB","url":"https://git.kernel.org/stable/c/ac758e1f663fe9bc64f6b47212a2aa18697524f5"},{"type":"WEB","url":"https://git.kernel.org/stable/c/c65f72eec60a34ace031426e04e9aff8e5f04895"},{"type":"WEB","url":"https://git.kernel.org/stable/c/f558120cd709682b739207b48cf7479fd9568431"},{"type":"WEB","url":"https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/42xxx/CVE-2024-42271.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2024-42271"},{"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":"7d316b9453523498246e9e19a659c423d4c5081e"},{"fixed":"84f40b46787ecb67c7ad08a5bb1376141fa10c01"},{"fixed":"37652fbef9809411cea55ea5fa1a170e299efcd0"},{"fixed":"c65f72eec60a34ace031426e04e9aff8e5f04895"},{"fixed":"ac758e1f663fe9bc64f6b47212a2aa18697524f5"},{"fixed":"8b424c9e44111c5a76f41c6b741f8d4c4179d876"},{"fixed":"01437282fd3904810603f3dc98d2cac6b8b6fc84"},{"fixed":"69620522c48ce8215e5eb55ffbab8cafee8f407d"},{"fixed":"f558120cd709682b739207b48cf7479fd9568431"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2024-42271.json"}}],"schema_version":"1.7.5"}