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 --- scripts/module.lds.S | 63 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 63 insertions(+) create mode 100644 scripts/module.lds.S (limited to 'scripts/module.lds.S') diff --git a/scripts/module.lds.S b/scripts/module.lds.S new file mode 100644 index 000000000..d0f200428 --- /dev/null +++ b/scripts/module.lds.S @@ -0,0 +1,63 @@ +/* + * Common module linker script, always used when linking a module. + * Archs are free to supply their own linker scripts. ld will + * combine them automatically. + */ + +#include + +SECTIONS { + /DISCARD/ : { + *(.discard) + *(.discard.*) + *(.export_symbol) + *(.no_trim_symbol) + } + + __ksymtab 0 : ALIGN(8) { *(SORT(___ksymtab+*)) } + __kcrctab 0 : ALIGN(4) { *(SORT(___kcrctab+*)) } + __kflagstab 0 : ALIGN(1) { *(SORT(___kflagstab+*)) } + + .ctors 0 : ALIGN(8) { *(SORT(.ctors.*)) *(.ctors) } + .init_array 0 : ALIGN(8) { *(SORT(.init_array.*)) *(.init_array) } + + .altinstructions 0 : ALIGN(8) { KEEP(*(.altinstructions)) } + __bug_table 0 : ALIGN(8) { KEEP(*(__bug_table)) } + __jump_table 0 : ALIGN(8) { KEEP(*(__jump_table)) } + __ex_table 0 : ALIGN(4) { KEEP(*(__ex_table)) } + + __patchable_function_entries 0 : { *(__patchable_function_entries) } + + .init.klp_funcs 0 : ALIGN(8) { KEEP(*(.init.klp_funcs)) } + .init.klp_objects 0 : ALIGN(8) { KEEP(*(.init.klp_objects)) } + +#ifdef CONFIG_ARCH_USES_CFI_TRAPS + __kcfi_traps 0 : { KEEP(*(.kcfi_traps)) } +#endif + +#ifndef CONFIG_ARCH_WANTS_MODULES_TEXT_SECTIONS + .text 0 : { + *(.text .text.[0-9a-zA-Z_]*) + } +#endif + + .bss 0 : { + *(.bss .bss.[0-9a-zA-Z_]*) + *(.bss..L*) + } + + .data 0 : { + *(.data .data.[0-9a-zA-Z_]*) + *(.data..L*) + } + + .rodata 0 : { + *(.rodata .rodata.[0-9a-zA-Z_]*) + *(.rodata..L*) + } + + MOD_SEPARATE_CODETAG_SECTIONS() +} + +/* bring in arch-specific sections */ +#include -- cgit v1.3.1