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/ipv4/protocol.c | 70 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 70 insertions(+) create mode 100644 net/ipv4/protocol.c (limited to 'net/ipv4/protocol.c') diff --git a/net/ipv4/protocol.c b/net/ipv4/protocol.c new file mode 100644 index 000000000..691397994 --- /dev/null +++ b/net/ipv4/protocol.c @@ -0,0 +1,70 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * INET An implementation of the TCP/IP protocol suite for the LINUX + * operating system. INET is implemented using the BSD Socket + * interface as the means of communication with the user level. + * + * INET protocol dispatch tables. + * + * Authors: Ross Biro + * Fred N. van Kempen, + * + * Fixes: + * Alan Cox : Ahah! udp icmp errors don't work because + * udp_err is never called! + * Alan Cox : Added new fields for init and ready for + * proper fragmentation (_NO_ 4K limits!) + * Richard Colella : Hang on hash collision + * Vince Laviano : Modified inet_del_protocol() to correctly + * maintain copy bit. + */ +#include +#include +#include +#include +#include + +struct net_protocol __rcu *inet_protos[MAX_INET_PROTOS] __read_mostly; +EXPORT_SYMBOL(inet_protos); +const struct net_offload __rcu *inet_offloads[MAX_INET_PROTOS] __read_mostly; +EXPORT_SYMBOL(inet_offloads); + +int inet_add_protocol(const struct net_protocol *prot, unsigned char protocol) +{ + return !cmpxchg((const struct net_protocol **)&inet_protos[protocol], + NULL, prot) ? 0 : -1; +} +EXPORT_SYMBOL(inet_add_protocol); + +int inet_add_offload(const struct net_offload *prot, unsigned char protocol) +{ + return !cmpxchg((const struct net_offload **)&inet_offloads[protocol], + NULL, prot) ? 0 : -1; +} +EXPORT_SYMBOL(inet_add_offload); + +int inet_del_protocol(const struct net_protocol *prot, unsigned char protocol) +{ + int ret; + + ret = (cmpxchg((const struct net_protocol **)&inet_protos[protocol], + prot, NULL) == prot) ? 0 : -1; + + synchronize_net(); + + return ret; +} +EXPORT_SYMBOL(inet_del_protocol); + +int inet_del_offload(const struct net_offload *prot, unsigned char protocol) +{ + int ret; + + ret = (cmpxchg((const struct net_offload **)&inet_offloads[protocol], + prot, NULL) == prot) ? 0 : -1; + + synchronize_net(); + + return ret; +} +EXPORT_SYMBOL(inet_del_offload); -- cgit v1.3.1