From: Chen Zhongjin chenzhongjin@huawei.com
[ 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 | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 993b84cc1db5..099191716d4c 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -1566,7 +1566,8 @@ static int check_kprobe_address_safe(struct kprobe *p, preempt_disable();
/* Ensure it is not in reserved area nor out of text */ - if (!kernel_text_address((unsigned long) p->addr) || + if (!(core_kernel_text((unsigned long) p->addr) || + is_module_text_address((unsigned long) p->addr)) || within_kprobe_blacklist((unsigned long) p->addr) || jump_label_text_reserved(p->addr, p->addr) || find_bug((unsigned long)p->addr)) {