{"id":"AZL-106908","summary":"CVE-2026-98380 affecting package kernel 6.6.157.1-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: reject IDR error pointers when deleting actions\n\ntcf_action_delete() drops the reference held by its lookup before calling\ntcf_idr_delete_index() with the saved action index.  An unlocked\nclassifier can remove that action and reserve the same IDR slot with\nERR_PTR(-EBUSY) in between.\n\ntcf_idr_delete_index() only checks the lookup result for NULL.  It\ntherefore treats the reservation as a tc_action and dereferences\ntcfa_bindcnt.  A hardware execution breakpoint was used to schedule the\ninterleaving without changing the kernel source.  KASAN reported this\ndecoded trace:\n\n  BUG: KASAN: null-ptr-deref in tca_action_gd+0x5b9/0x1010\n  Read of size 4 at addr 0000000000000010 by task poc/150\n  Oops: general protection fault, probably for non-canonical address 0xdffffc0000000002\n  RIP: tca_action_gd+0x5c0/0x1010:\n    arch_atomic_read at arch/x86/include/asm/atomic.h:23\n    raw_atomic_read at include/linux/atomic/atomic-arch-fallback.h:457\n    atomic_read at include/linux/atomic/atomic-instrumented.h:33\n    tcf_idr_delete_index at net/sched/act_api.c:766\n    tcf_action_delete at net/sched/act_api.c:1859\n    tcf_del_notify at net/sched/act_api.c:2014\n    tca_action_gd at net/sched/act_api.c:2064\n  R13: 0000000000000010 R15: fffffffffffffff0\n  Kernel panic - not syncing: Fatal exception\n\nR15 contains ERR_PTR(-EBUSY), and adding the tcfa_bindcnt offset produces\nthe address in R13.  With the guard applied, the same reproducer returned\n-ENOENT without a KASAN report or panic.  Treat error pointers as absent\nand return -ENOENT.","modified":"2026-10-10T14:17:32.431754770Z","published":"2026-10-09T08:16:56Z","upstream":["CVE-2026-98380"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98380"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"6.6.157.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-106908.json"}}],"schema_version":"1.9.0"}