{"id":"CVE-2026-98380","summary":"net/sched: reject IDR error pointers when deleting actions","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":"2026-10-10T02:47:25.599604288Z","published":"2026-10-09T07:34:20.218Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98380.json","cna_assigner":"Linux"},"references":[{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"},{"type":"WEB","url":"https://git.kernel.org/stable/c/259caa711b7688365676442e2fdb286b8aceaa80"},{"type":"WEB","url":"https://git.kernel.org/stable/c/39b751a210bf61a374afa82749afc7a77a08bf1d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/6bf076258aac4e0af69ef317656c31ce6444d647"},{"type":"WEB","url":"https://git.kernel.org/stable/c/6c9f07bf8800171de2cd3f02815cebe1f4d45f2d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/968550a439f64bd1a6c0d88efb92e4f082f84a26"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a9551f26287debe6d8aa6e8841974661065b975f"},{"type":"WEB","url":"https://git.kernel.org/stable/c/c82b797abe668d0b668601a93ba2c0b071a63574"},{"type":"WEB","url":"https://git.kernel.org/stable/c/dd80a7519824b72c8fcfd3cc50cb93f7e2d90923"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98380.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98380"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"0190c1d452a91c38a3462abdd81752be1b9006a8"},{"fixed":"39b751a210bf61a374afa82749afc7a77a08bf1d"},{"fixed":"dd80a7519824b72c8fcfd3cc50cb93f7e2d90923"},{"fixed":"6bf076258aac4e0af69ef317656c31ce6444d647"},{"fixed":"6c9f07bf8800171de2cd3f02815cebe1f4d45f2d"},{"fixed":"259caa711b7688365676442e2fdb286b8aceaa80"},{"fixed":"968550a439f64bd1a6c0d88efb92e4f082f84a26"},{"fixed":"a9551f26287debe6d8aa6e8841974661065b975f"},{"fixed":"c82b797abe668d0b668601a93ba2c0b071a63574"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98380.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.19.0"},{"fixed":"5.10.271"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.222"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.189"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.158"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.112"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.55"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.2.9"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98380.json"}}],"schema_version":"1.9.0"}