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 --- usr/dummy-include/endian.h | 0 usr/dummy-include/limits.h | 8 ++++++++ usr/dummy-include/netinet/if_ether.h | 0 usr/dummy-include/netinet/in.h | 0 usr/dummy-include/stddef.h | 13 +++++++++++++ usr/dummy-include/stdint.h | 17 +++++++++++++++++ usr/dummy-include/string.h | 12 ++++++++++++ usr/dummy-include/sys/ioctl.h | 0 usr/dummy-include/sys/socket.h | 12 ++++++++++++ usr/dummy-include/sys/time.h | 3 +++ usr/dummy-include/sys/types.h | 0 usr/dummy-include/time.h | 0 usr/dummy-include/unistd.h | 0 13 files changed, 65 insertions(+) create mode 100644 usr/dummy-include/endian.h create mode 100644 usr/dummy-include/limits.h create mode 100644 usr/dummy-include/netinet/if_ether.h create mode 100644 usr/dummy-include/netinet/in.h create mode 100644 usr/dummy-include/stddef.h create mode 100644 usr/dummy-include/stdint.h create mode 100644 usr/dummy-include/string.h create mode 100644 usr/dummy-include/sys/ioctl.h create mode 100644 usr/dummy-include/sys/socket.h create mode 100644 usr/dummy-include/sys/time.h create mode 100644 usr/dummy-include/sys/types.h create mode 100644 usr/dummy-include/time.h create mode 100644 usr/dummy-include/unistd.h (limited to 'usr/dummy-include') diff --git a/usr/dummy-include/endian.h b/usr/dummy-include/endian.h new file mode 100644 index 000000000..e69de29bb diff --git a/usr/dummy-include/limits.h b/usr/dummy-include/limits.h new file mode 100644 index 000000000..49b17c10c --- /dev/null +++ b/usr/dummy-include/limits.h @@ -0,0 +1,8 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +#ifndef _DUMMY_LIMITS_H +#define _DUMMY_LIMITS_H + +#define INT_MAX ((int)(~0U >> 1)) +#define INT_MIN (-INT_MAX - 1) + +#endif /* _DUMMY_LIMITS_H */ diff --git a/usr/dummy-include/netinet/if_ether.h b/usr/dummy-include/netinet/if_ether.h new file mode 100644 index 000000000..e69de29bb diff --git a/usr/dummy-include/netinet/in.h b/usr/dummy-include/netinet/in.h new file mode 100644 index 000000000..e69de29bb diff --git a/usr/dummy-include/stddef.h b/usr/dummy-include/stddef.h new file mode 100644 index 000000000..525489daf --- /dev/null +++ b/usr/dummy-include/stddef.h @@ -0,0 +1,13 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +#ifndef _DUMMY_STDDEF_H +#define _DUMMY_STDDEF_H + +#define offsetof(TYPE, MEMBER) __builtin_offsetof(TYPE, MEMBER) + +#ifdef __cplusplus +#define NULL 0 +#else +#define NULL ((void *)0) +#endif + +#endif /* _DUMMY_STDDEF_H */ diff --git a/usr/dummy-include/stdint.h b/usr/dummy-include/stdint.h new file mode 100644 index 000000000..93b1962fd --- /dev/null +++ b/usr/dummy-include/stdint.h @@ -0,0 +1,17 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +#ifndef _DUMMY_STDINT_H +#define _DUMMY_STDINT_H + +#include + +typedef __u64 uint64_t; +typedef __u32 uint32_t; +typedef __u16 uint16_t; +typedef __u8 uint8_t; + +typedef __s64 int64_t; +typedef __s32 int32_t; +typedef __s16 int16_t; +typedef __s8 int8_t; + +#endif /* _DUMMY_STDINT_H */ diff --git a/usr/dummy-include/string.h b/usr/dummy-include/string.h new file mode 100644 index 000000000..e059808d3 --- /dev/null +++ b/usr/dummy-include/string.h @@ -0,0 +1,12 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +#ifndef _DUMMY_STRING_H +#define _DUMMY_STRING_H + +#include + +#define memset(_s, _c, _n) __builtin_memset(_s, _c, _n) +#define memcpy(_dest, _src, _n) __builtin_memcpy(_dest, _src, _n) + +#define strlen(_s) __builtin_strlen(_s) + +#endif /* _DUMMY_STRING_H */ diff --git a/usr/dummy-include/sys/ioctl.h b/usr/dummy-include/sys/ioctl.h new file mode 100644 index 000000000..e69de29bb diff --git a/usr/dummy-include/sys/socket.h b/usr/dummy-include/sys/socket.h new file mode 100644 index 000000000..748751f9e --- /dev/null +++ b/usr/dummy-include/sys/socket.h @@ -0,0 +1,12 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +#ifndef _DUMMY_SYS_SOCKET_H +#define _DUMMY_SYS_SOCKET_H + +#include + +struct sockaddr { + __kernel_sa_family_t sa_family; /* address family, AF_xxx */ + char sa_data[14]; /* 14 bytes of protocol address */ +}; + +#endif /* _DUMMY_SYS_SOCKET_H */ diff --git a/usr/dummy-include/sys/time.h b/usr/dummy-include/sys/time.h new file mode 100644 index 000000000..9817b8afb --- /dev/null +++ b/usr/dummy-include/sys/time.h @@ -0,0 +1,3 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ + +#include diff --git a/usr/dummy-include/sys/types.h b/usr/dummy-include/sys/types.h new file mode 100644 index 000000000..e69de29bb diff --git a/usr/dummy-include/time.h b/usr/dummy-include/time.h new file mode 100644 index 000000000..e69de29bb diff --git a/usr/dummy-include/unistd.h b/usr/dummy-include/unistd.h new file mode 100644 index 000000000..e69de29bb -- cgit v1.3.1