From 33a154a96e71a34a1bcca9f40da343dbbf7b38b4 Mon Sep 17 00:00:00 2001 From: Alexei Starovoitov Date: Thu, 1 Oct 2026 14:52:55 +0000 Subject: selftests/bpf: Test packet range of pointers sharing an id 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 --- net/batman-adv/bitarray.h | 56 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 56 insertions(+) create mode 100644 net/batman-adv/bitarray.h (limited to 'net/batman-adv/bitarray.h') diff --git a/net/batman-adv/bitarray.h b/net/batman-adv/bitarray.h new file mode 100644 index 000000000..2b9f5dbb3 --- /dev/null +++ b/net/batman-adv/bitarray.h @@ -0,0 +1,56 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* Copyright (C) B.A.T.M.A.N. contributors: + * + * Simon Wunderlich, Marek Lindner + */ + +#ifndef _NET_BATMAN_ADV_BITARRAY_H_ +#define _NET_BATMAN_ADV_BITARRAY_H_ + +#include "main.h" + +#include +#include +#include +#include + +/** + * batadv_test_bit() - check if bit is set in the current window + * + * @seq_bits: pointer to the sequence number bitmap of received packets + * @last_seqno: latest sequence number in seq_bits + * @curr_seqno: sequence number to test for + * + * Return: true if the corresponding bit in the given seq_bits indicates true + * and curr_seqno is within range of last_seqno. Otherwise returns false. + */ +static inline bool batadv_test_bit(const unsigned long *seq_bits, + u32 last_seqno, u32 curr_seqno) +{ + s32 diff; + + diff = last_seqno - curr_seqno; + if (diff < 0 || diff >= BATADV_TQ_LOCAL_WINDOW_SIZE) + return false; + return test_bit(diff, seq_bits) != 0; +} + +/** + * batadv_set_bit() - Turn corresponding bit on, so we can remember that we got + * the packet + * @seq_bits: bitmap of the packet receive window + * @n: relative sequence number of newly received packet + */ +static inline void batadv_set_bit(unsigned long *seq_bits, s32 n) +{ + /* if too old, just drop it */ + if (n < 0 || n >= BATADV_TQ_LOCAL_WINDOW_SIZE) + return; + + set_bit(n, seq_bits); /* turn the position on */ +} + +bool batadv_bit_get_packet(void *priv, unsigned long *seq_bits, + s32 seq_num_diff, int set_mark); + +#endif /* _NET_BATMAN_ADV_BITARRAY_H_ */ -- cgit v1.3.1