{"id":"AZL-47808","summary":"CVE-2024-42271 affecting package kernel for versions less than 6.6.47.1-1","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":"2026-04-01T05:15:57.884731Z","published":"2024-08-17T09:15:08Z","upstream":["CVE-2024-42271"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2024-42271"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.6.47.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-47808.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"}]}