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 --- include/trace/events/exceptions.h | 43 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+) create mode 100644 include/trace/events/exceptions.h (limited to 'include/trace/events/exceptions.h') diff --git a/include/trace/events/exceptions.h b/include/trace/events/exceptions.h new file mode 100644 index 000000000..a631f8de8 --- /dev/null +++ b/include/trace/events/exceptions.h @@ -0,0 +1,43 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#undef TRACE_SYSTEM +#define TRACE_SYSTEM exceptions + +#if !defined(_TRACE_PAGE_FAULT_H) || defined(TRACE_HEADER_MULTI_READ) +#define _TRACE_PAGE_FAULT_H + +#include + +DECLARE_EVENT_CLASS(exceptions, + + TP_PROTO(unsigned long address, struct pt_regs *regs, + unsigned long error_code), + + TP_ARGS(address, regs, error_code), + + TP_STRUCT__entry( + __field( unsigned long, address ) + __field( unsigned long, ip ) + __field( unsigned long, error_code ) + ), + + TP_fast_assign( + __entry->address = address; + __entry->ip = instruction_pointer(regs); + __entry->error_code = error_code; + ), + + TP_printk("address=%ps ip=%ps error_code=0x%lx", + (void *)__entry->address, (void *)__entry->ip, + __entry->error_code) ); + +DEFINE_EVENT(exceptions, page_fault_user, + TP_PROTO(unsigned long address, struct pt_regs *regs, unsigned long error_code), + TP_ARGS(address, regs, error_code)); +DEFINE_EVENT(exceptions, page_fault_kernel, + TP_PROTO(unsigned long address, struct pt_regs *regs, unsigned long error_code), + TP_ARGS(address, regs, error_code)); + +#endif /* _TRACE_PAGE_FAULT_H */ + +/* This part must be outside protection */ +#include -- cgit v1.3.1