From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4A31F1CDFAC; Sun, 7 Sep 2025 20:13:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757275991; cv=none; b=D7TjBmHInTtBWl5fhgDUuh4BvXHncdb1i9znb82K7ACSlrxNTIvGkyUF5pfo40giNvwYlCV3PBmtMUvbvUvXmhzgyI54VRiEFYmscGJ28c28dOi6rMhqldXqjE4DRt5NogE9Na8/sOiy/a7jkiqv9VyoI6JEldxCxNSWLk09bJU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757275991; c=relaxed/simple; bh=brAl6CDQW3vAzOmU76K1DoevL2m3PJIL4pX25Fdh/gU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=DvPXcWI93xFNQ8OtsZdKt5WckKpNzO0Y8vo2lRBk6AZynAMO/f+aWgQYy+fRsm5QM9YCjZY2H2ZgEuZWfeiL7wfQxuYQCFIktMC86zMBGHSWQf3QuBIQiBtrXwYnTd+fI6cWlMtKzvcfLZeq6VdB7TODy7ePAhdTQPWi8Ty7riE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=JDSGRYjM; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="JDSGRYjM" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 63C8DC4CEF0; Sun, 7 Sep 2025 20:13:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1757275990; bh=brAl6CDQW3vAzOmU76K1DoevL2m3PJIL4pX25Fdh/gU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JDSGRYjMA3lO9dBH4NcwxQ4i3U9UrPnb4VH2bsYC2y9yt8YCEi0dnDYUTKdOU0ZSb RyPpSRj8LhCjmUwXMWZuTDklUF+AbhfcnOhhBBQ7nvluSPc77lfXS28wf0Tjn18Tuv JdZvz+zmJ0Lfx1pzUhaLu0coj1lenLKpNa1EX4hA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Lonial Con , Daniel Borkmann , Alexei Starovoitov , Sasha Levin Subject: [PATCH 5.15 04/64] bpf: Fix oob access in cgroup local storage Date: Sun, 7 Sep 2025 21:57:46 +0200 Message-ID: <20250907195603.518574121@linuxfoundation.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20250907195603.394640159@linuxfoundation.org> References: <20250907195603.394640159@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Daniel Borkmann [ Upstream commit abad3d0bad72a52137e0c350c59542d75ae4f513 ] Lonial reported that an out-of-bounds access in cgroup local storage can be crafted via tail calls. Given two programs each utilizing a cgroup local storage with a different value size, and one program doing a tail call into the other. The verifier will validate each of the indivial programs just fine. However, in the runtime context the bpf_cg_run_ctx holds an bpf_prog_array_item which contains the BPF program as well as any cgroup local storage flavor the program uses. Helpers such as bpf_get_local_storage() pick this up from the runtime context: ctx = container_of(current->bpf_ctx, struct bpf_cg_run_ctx, run_ctx); storage = ctx->prog_item->cgroup_storage[stype]; if (stype == BPF_CGROUP_STORAGE_SHARED) ptr = &READ_ONCE(storage->buf)->data[0]; else ptr = this_cpu_ptr(storage->percpu_buf); For the second program which was called from the originally attached one, this means bpf_get_local_storage() will pick up the former program's map, not its own. With mismatching sizes, this can result in an unintended out-of-bounds access. To fix this issue, we need to extend bpf_map_owner with an array of storage_cookie[] to match on i) the exact maps from the original program if the second program was using bpf_get_local_storage(), or ii) allow the tail call combination if the second program was not using any of the cgroup local storage maps. Fixes: 7d9c3427894f ("bpf: Make cgroup storages shared between programs on the same cgroup") Reported-by: Lonial Con Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/r/20250730234733.530041-4-daniel@iogearbox.net Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin --- include/linux/bpf.h | 1 + kernel/bpf/core.c | 15 +++++++++++++++ 2 files changed, 16 insertions(+) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index ea6728c304fe0..1046f290b4b2b 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -256,6 +256,7 @@ struct bpf_map_owner { enum bpf_prog_type type; bool jited; bool xdp_has_frags; + u64 storage_cookie[MAX_BPF_CGROUP_STORAGE_TYPE]; const struct btf_type *attach_func_proto; }; diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index aa3487e244549..73a1c66e54175 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -1837,7 +1837,9 @@ static bool __bpf_prog_map_compatible(struct bpf_map *map, { enum bpf_prog_type prog_type = fp->aux->dst_prog ? fp->aux->dst_prog->type : fp->type; struct bpf_prog_aux *aux = fp->aux; + enum bpf_cgroup_storage_type i; bool ret = false; + u64 cookie; if (fp->kprobe_override) return ret; @@ -1853,12 +1855,25 @@ static bool __bpf_prog_map_compatible(struct bpf_map *map, /* Note: xdp_has_frags doesn't exist in aux yet in our branch */ /* map->owner->xdp_has_frags = aux->xdp_has_frags; */ map->owner->attach_func_proto = aux->attach_func_proto; + for_each_cgroup_storage_type(i) { + map->owner->storage_cookie[i] = + aux->cgroup_storage[i] ? + aux->cgroup_storage[i]->cookie : 0; + } ret = true; } else { ret = map->owner->type == prog_type && map->owner->jited == fp->jited; /* Note: xdp_has_frags check would go here when available */ /* && map->owner->xdp_has_frags == aux->xdp_has_frags; */ + for_each_cgroup_storage_type(i) { + if (!ret) + break; + cookie = aux->cgroup_storage[i] ? + aux->cgroup_storage[i]->cookie : 0; + ret = map->owner->storage_cookie[i] == cookie || + !cookie; + } if (ret && map->owner->attach_func_proto != aux->attach_func_proto) { switch (prog_type) { -- 2.50.1