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[192.26.29.3]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-49e7d28c734sm61916215e9.1.2026.09.15.07.14.51 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 15 Sep 2026 07:14:52 -0700 (PDT) Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=UTF-8 Date: Tue, 15 Sep 2026 16:14:51 +0200 Message-Id: Cc: "Alexei Starovoitov" , "Andrii Nakryiko" , "Daniel Borkmann" , "Eduard Zingerman" , "Emil Tsalapatis" , "Tejun Heo" , , , "Amery Hung" Subject: Re: [PATCH bpf-next v1 0/3] Fix generic __uninit kfunc output buffers From: "Kumar Kartikeya Dwivedi" To: X-Mailer: aerc 0.21.0 References: <20260915141004.1196460-1-memxor@gmail.com> In-Reply-To: <20260915141004.1196460-1-memxor@gmail.com> +Cc Amery, sorry for missing it. On Tue Sep 15, 2026 at 4:10 PM CEST, Kumar Kartikeya Dwivedi wrote: > Generic __uninit kfunc arguments are output buffers. Their stack > liveness already treats them as writes, but argument checking still > requires readable contents and does not record definite initialization > after the call. Check these arguments as write-only and reuse helper > output-buffer tracking, with one entry per argument slot. > > Kumar Kartikeya Dwivedi (3): > bpf: Fix generic __uninit kfunc output buffers > selftests/bpf: Allow privileged preparation for capability tests > selftests/bpf: Cover generic __uninit kfunc output buffers > > Documentation/bpf/kfuncs.rst | 27 +- > include/linux/bpf_verifier.h | 11 +- > kernel/bpf/verifier.c | 70 ++- > .../selftests/bpf/prog_tests/verifier.c | 2 + > tools/testing/selftests/bpf/progs/bpf_misc.h | 9 +- > .../bpf/progs/verifier_kfunc_uninit.c | 399 ++++++++++++++++++ > .../selftests/bpf/test_kmods/bpf_testmod.c | 56 +++ > .../bpf/test_kmods/bpf_testmod_kfunc.h | 9 + > tools/testing/selftests/bpf/test_loader.c | 41 +- > 9 files changed, 577 insertions(+), 47 deletions(-) > create mode 100644 tools/testing/selftests/bpf/progs/verifier_kfunc_unin= it.c > > > base-commit: 5ef40d69b38a93bc9951dadb1a15c85c597e1a40