{"id":"CVE-2026-98380","published":"2026-10-09T08:16:56.400","lastModified":"2026-10-09T08:16:56.400","description":"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.","cvssScore":null,"cvssSeverity":null,"cvssVector":null,"cwes":[],"vendors":[],"products":[],"references":[{"url":"https://git.kernel.org/stable/c/259caa711b7688365676442e2fdb286b8aceaa80","tags":[]},{"url":"https://git.kernel.org/stable/c/39b751a210bf61a374afa82749afc7a77a08bf1d","tags":[]},{"url":"https://git.kernel.org/stable/c/6bf076258aac4e0af69ef317656c31ce6444d647","tags":[]},{"url":"https://git.kernel.org/stable/c/6c9f07bf8800171de2cd3f02815cebe1f4d45f2d","tags":[]},{"url":"https://git.kernel.org/stable/c/968550a439f64bd1a6c0d88efb92e4f082f84a26","tags":[]},{"url":"https://git.kernel.org/stable/c/a9551f26287debe6d8aa6e8841974661065b975f","tags":[]},{"url":"https://git.kernel.org/stable/c/c82b797abe668d0b668601a93ba2c0b071a63574","tags":[]},{"url":"https://git.kernel.org/stable/c/dd80a7519824b72c8fcfd3cc50cb93f7e2d90923","tags":[]}],"exploitRefs":[],"hasPoc":false,"ai":null}