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/syscall.h | 57 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 57 insertions(+) create mode 100644 include/trace/syscall.h (limited to 'include/trace/syscall.h') diff --git a/include/trace/syscall.h b/include/trace/syscall.h new file mode 100644 index 000000000..0dd7f2b33 --- /dev/null +++ b/include/trace/syscall.h @@ -0,0 +1,57 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _TRACE_SYSCALL_H +#define _TRACE_SYSCALL_H + +#include +#include +#include +#include + +#include + + +/* + * A syscall entry in the ftrace syscalls array. + * + * @name: name of the syscall + * @syscall_nr: number of the syscall + * @nb_args: number of parameters it takes + * @user_arg_is_str: set if the arg for @user_arg_size is a string + * @user_arg_size: holds @arg that has size of the user space to read + * @user_mask: mask of @args that will read user space + * @types: list of types as strings + * @args: list of args as strings (args[i] matches types[i]) + * @enter_fields: list of fields for syscall_enter trace event + * @enter_event: associated syscall_enter trace event + * @exit_event: associated syscall_exit trace event + */ +struct syscall_metadata { + const char *name; + int syscall_nr; + u8 nb_args:7; + u8 user_arg_is_str:1; + s8 user_arg_size; + short user_mask; + const char **types; + const char **args; + struct list_head enter_fields; + + struct trace_event_call *enter_event; + struct trace_event_call *exit_event; +}; + +#if defined(CONFIG_TRACEPOINTS) && defined(CONFIG_HAVE_SYSCALL_TRACEPOINTS) +static inline void syscall_tracepoint_update(struct task_struct *p) +{ + if (test_syscall_work(SYSCALL_TRACEPOINT)) + set_task_syscall_work(p, SYSCALL_TRACEPOINT); + else + clear_task_syscall_work(p, SYSCALL_TRACEPOINT); +} +#else +static inline void syscall_tracepoint_update(struct task_struct *p) +{ +} +#endif + +#endif /* _TRACE_SYSCALL_H */ -- cgit v1.3.1