kprobes: Forbid probing on trampoline and BPF code areas
authorChen Zhongjin <chenzhongjin@huawei.com>
Mon, 1 Aug 2022 03:37:19 +0000 (11:37 +0800)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 25 Aug 2022 09:11:26 +0000 (11:11 +0200)
commit4262b6eb057d86c7829168c541654fe0d48fdac8
treebc675b398ca9a92fe41843ca67826d26883efeb5
parent6263ec8032c411b8ef6b7f00198cb18c855ee6cb
kprobes: Forbid probing on trampoline and BPF code areas

[ Upstream commit 28f6c37a2910f565b4f5960df52b2eccae28c891 ]

kernel_text_address() treats ftrace_trampoline, kprobe_insn_slot
and bpf_text_address as valid kprobe addresses - which is not ideal.

These text areas are removable and changeable without any notification
to kprobes, and probing on them can trigger unexpected behavior:

  https://lkml.org/lkml/2022/7/26/1148

Considering that jump_label and static_call text are already
forbiden to probe, kernel_text_address() should be replaced with
core_kernel_text() and is_module_text_address() to check other text
areas which are unsafe to kprobe.

[ mingo: Rewrote the changelog. ]

Fixes: 5b485629ba0d ("kprobes, extable: Identify kprobes trampolines as kernel text area")
Fixes: 74451e66d516 ("bpf: make jited programs visible in traces")
Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Link: https://lore.kernel.org/r/20220801033719.228248-1-chenzhongjin@huawei.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
kernel/kprobes.c