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 --- lib/net_utils.c | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) create mode 100644 lib/net_utils.c (limited to 'lib/net_utils.c') diff --git a/lib/net_utils.c b/lib/net_utils.c new file mode 100644 index 000000000..215cda672 --- /dev/null +++ b/lib/net_utils.c @@ -0,0 +1,27 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include +#include + +bool mac_pton(const char *s, u8 *mac) +{ + int i; + + if (strnlen(s, MAC_ADDR_STR_LEN) < MAC_ADDR_STR_LEN) + return false; + + /* Don't dirty result unless string is valid MAC. */ + for (i = 0; i < ETH_ALEN; i++) { + if (!isxdigit(s[i * 3]) || !isxdigit(s[i * 3 + 1])) + return false; + if (i != ETH_ALEN - 1 && s[i * 3 + 2] != ':') + return false; + } + for (i = 0; i < ETH_ALEN; i++) { + mac[i] = (hex_to_bin(s[i * 3]) << 4) | hex_to_bin(s[i * 3 + 1]); + } + return true; +} +EXPORT_SYMBOL(mac_pton); -- cgit v1.3.1