laptop-kernel/tools/testing/selftests/bpf, branch master

selftests/bpf: Add a test for objects stuck in free_by_rcu_ttrace

2026-10-01T16:40:05Z

Delete all elements of BPF_F_NO_PREALLOC hash map in one batch. The first free_bulk() starts RCU tasks trace GP and the rest of the elements are freed while it's in flight. Wait for call_rcu_ttrace_in_progress to clear in bpf_mem_cache of every cpu and check that free_by_rcu_ttrace and waiting_for_gp_ttrace lists are empty. Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20260930095920.601738-4-alexei.starovoitov@gmail.com Signed-off-by: Kumar Kartikeya Dwivedi

selftests/bpf: Test packet range of pointers sharing an id

2026-10-01T16:39:27Z

Add tests where two packet pointers share an id and tightening one pointer's umax from its var_off would put it less than their constant distance from the other's umax: with an index & 0x38 capped at 50, the base pointer keeps umax 50, so the pointer 8 bytes further on must keep umax 58, even though its known bits allow at most 56. These refused a valid program or accepted an out-of-bounds access before the fix: - check the advanced copy, load through the base: valid, was refused; - check the base, load the byte at base + 1 through a copy advanced by 8: was accepted; - check base + 4, load 4 bytes at base + 2 through base + 8: reads two bytes past the checked range, was accepted; - the same as the second with data_meta pointers checked against data: was accepted. These pass with and without the fix and cover nearby paths: - subtract an unknown scalar from a checked pointer and load below it (the range is kept across a new id); - reach a load through two paths whose checks cover 8 and 7 bytes after the loaded pointer; the second path must not be pruned by the first; - spill a copy of a pointer, check the pointer, fill the copy and load one byte past the checked range: the load is refused, and the copy has the range of the check. Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20261001145255.855630-2-alexei.starovoitov@gmail.com Signed-off-by: Kumar Kartikeya Dwivedi

bpf: Fix packet range of pointers sharing an id

2026-10-01T16:39:27Z

Since commit 022ac0750883 ("bpf: use reg->var_off instead of reg->off for pointers"), find_good_pkt_pointers() sets the range of all packet pointers sharing an id from the umax of the compared pointer, and check_packet_access() requires umax + off + size <= range. That assumes the umax of two such pointers differ by exactly their constant distance. reg_bounds_sync() breaks it when var_off tightens one umax and not the other: r4 &= 0x38 if r4 > 50 goto exit ; umax 50, var_off (0x0; 0x38) r5 = pkt + r4 ; umax 50 r6 = r5 r6 += 8 ; umax 56, not 58 Comparing r6 with pkt_end sets the range to 56, and the valid 8-byte load at r5 is rejected (50 + 8 > 56). Comparing r5 sets it to 50, and the out-of-bounds 1-byte load at r6 - 7, i.e. r5 + 1, is accepted (56 - 7 + 1 <= 50). Don't call reg_bounds_sync() on a packet pointer that keeps its id (a constant was added or subtracted) or its range (an unknown non-negative value was subtracted), so that var_off cannot tighten its umax. Only update the 32-bit bounds from var_off: reg_bounds_sanity_check() wants them constant when the lower half of var_off is, e.g. for pkt + 8. This relies on nothing else changing the 64-bit bounds of a packet pointer, which holds today. var_off of such a pointer is no longer narrowed by its bounds. Adjust three verifier_align expectations; the low bits, which the alignment checks use, don't change. veristat on the selftests shows no verdict changes and +0.8% insns in test_cls_redirect_subprogs. Fixes: 022ac0750883 ("bpf: use reg->var_off instead of reg->off for pointers") Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20261001145255.855630-1-alexei.starovoitov@gmail.com Signed-off-by: Kumar Kartikeya Dwivedi

selftests/bpf: Detach a trampoline prog while a task sleeps before it

2026-09-29T05:54:16Z

Add a test for the use-after-free fixed by the previous commit. A sleepable prog on bpf_fentry_test1() blocks a task on a userfaultfd page, like bpf_mod_race does, while the two progs that run after it in the same trampoline are detached and freed one after the other, which the test knows from their .bss maps going away. After the first detach the task is in an image that isn't the trampoline's current one anymore. The task is then released and must not call into the freed progs. This is done with fentry progs, with fexit progs, where the task is already past the original function, and with a task sleeping in a fentry prog while fexit progs are detached, where the original function must still be called. bpf_mod_race's userfaultfd helper moves to testing_helpers.c so that both tests can use it. Without the fix, on a kernel with KASAN: BUG: KASAN: vmalloc-out-of-bounds in __bpf_prog_enter_recur+0xed/0x1e0 Read of size 8 at addr ffa0000000144040 by task test_progs/171 CPU: 6 UID: 0 PID: 171 Comm: test_progs Tainted: G OE 7.2.0+ #1 PREEMPT(full) Call Trace: __bpf_prog_enter_recur+0xed/0x1e0 bpf_trampoline_6442545468+0x72/0xe3 bpf_fentry_test1+0x9/0x20 bpf_prog_test_run_tracing+0x183/0x3e0 __sys_bpf+0xd3f/0x38f0 ... Signed-off-by: Florent Revest (Anthropic) Signed-off-by: Alexei Starovoitov Link: https://patch.msgid.link/20260926135605.1217928-4-florent.revest@linux.dev

selftests/bpf: Test per-cpu initialization of a BPF_F_CPU created element

2026-09-24T14:24:52Z

The existing cpu_flag subtests always prime a key with BPF_F_ALL_CPUS before any BPF_F_CPU write, so the create path is never covered. Add a subtest that creates the element with BPF_F_CPU on a map with max_entries 1, so the key can only reuse the element the previous key released, and check that the CPUs the update did not name read back zero. Run it for PERCPU_HASH preallocated and BPF_F_NO_PREALLOC, whose per-cpu areas come from different allocators, and for LRU_PERCPU_HASH. Under BPF_F_NO_PREALLOC the reuse is only guaranteed on the cpu that ran the delete, so pin the thread across the pair, and name a cpu other than that one in map_flags. Signed-off-by: Donggeun Yoo Signed-off-by: Alexei Starovoitov Link: https://patch.msgid.link/20260924102321.2120434-3-donggeunyoo.kernel@gmail.com

selftests/bpf: Test for mixed arena/nonarena code paths

2026-09-22T19:34:05Z

Add a selftest to confirm the verifier rejects ALU operations that return arena or non-arena results depending on code path. Signed-off-by: Emil Tsalapatis Signed-off-by: Alexei Starovoitov Link: https://patch.msgid.link/20260922172028.6269-9-emil@etsalapatis.com

selftests/bpf: Test rejection of pkt args to mutating subprogs

2026-09-22T19:34:04Z

Add a selftests that ensures that PTR_TO_PACKET arguments can only be passed to subprogs that will never adjust the underlying packet memory, and are rejected otherwise. Signed-off-by: Emil Tsalapatis Signed-off-by: Alexei Starovoitov Link: https://patch.msgid.link/20260922172028.6269-7-emil@etsalapatis.com

selftests/bpf: Add selftests for rx_queue_mapping context access

2026-09-22T19:34:04Z

Add tests to ensure the verifier properly tracks the 0 bit state and width of the rx_queue_mapping field read from struct sock. Signed-off-by: Emil Tsalapatis Signed-off-by: Alexei Starovoitov Link: https://patch.msgid.link/20260922172028.6269-5-emil@etsalapatis.com

selftests/bpf: Test dynptr slices past end of skb

2026-09-22T19:34:04Z

Add a selftest to ensure dynptr slices cannot include past the end of the linear area of an skb. Signed-off-by: Emil Tsalapatis Signed-off-by: Alexei Starovoitov Link: https://patch.msgid.link/20260922172028.6269-3-emil@etsalapatis.com

selftests/bpf: Reject iterator destruction through fp+0

2026-09-21T22:00:59Z

Add a verifier regression test that initializes a numeric iterator at fp-8 and attempts to destroy it through fp+0. The verifier must reject the non-negative offset instead of treating it as the initialized stack slot. Check the offset diagnostic to ensure rejection happens at the stack object address check. The numeric iterator destroy operation is a no-op; this test checks verifier rejection and does not run the program. Signed-off-by: Xu Yunxiang Signed-off-by: Andrii Nakryiko Reviewed-by: Sun Jian Link: https://lore.kernel.org/bpf/20260920210423.345636-3-xyx2021@mail.ustc.edu.cn