From d7ef1afd5b3f43f4924326164cee5397b66abd9c Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Wed, 2 Jul 2025 18:21:44 +0200 Subject: [PATCH] perf: Revert to requiring CAP_SYS_ADMIN for uprobes [ Upstream commit ba677dbe77af5ffe6204e0f3f547f3ba059c6302 ] Jann reports that uprobes can be used destructively when used in the middle of an instruction. The kernel only verifies there is a valid instruction at the requested offset, but due to variable instruction length cannot determine if this is an instruction as seen by the intended execution stream. Additionally, Mark Rutland notes that on architectures that mix data in the text segment (like arm64), a similar things can be done if the data word is 'mistaken' for an instruction. As such, require CAP_SYS_ADMIN for uprobes. Fixes: c9e0924e5c2b ("perf/core: open access to probes for CAP_PERFMON privileged process") Reported-by: Jann Horn Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/CAG48ez1n4520sq0XrWYDHKiKxE_+WCfAK+qt9qkY4ZiBGmL-5g@mail.gmail.com Signed-off-by: Sasha Levin --- kernel/events/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/events/core.c b/kernel/events/core.c index b133abe23a4b1..bf9f9eab6f67f 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -9823,7 +9823,7 @@ static int perf_uprobe_event_init(struct perf_event *event) if (event->attr.type != perf_uprobe.type) return -ENOENT; - if (!perfmon_capable()) + if (!capable(CAP_SYS_ADMIN)) return -EACCES; /* -- 2.47.3