From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 6799A35C1BC; Sat, 17 Oct 2026 16:18:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792253907; cv=none; b=WTHZwgZDhwXCCokyHJEM4jBvqwPAYFfgyAWqfQtJ2Nl6UxcLlmNrrTNmcrb56yqzlCxpMsRoBifuNlUF+KAEQUj+nT9coU+VtS0qP9KPnj0xRj5xD+x1LpD2FGuyXejUpxrOuc/oUNKoSp+QZNJw+upa3V4ZF0Gi7tGtdJqi34k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792253907; c=relaxed/simple; bh=rZ2jCnQj8zQ1CAhOC9XWeDSy7yQEGeJguhrfaa6cjkg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=NYplKYClBWSH+J1PU6hD8qXlrzHZteMjurF1ryeuFUaXIR2GWtJN+hdmn/irTuIpiE0+VJFVPE3uYRh3DJhwLH4elyXqRHq9m7csY3HT2T1gwTr7rJrMU7y7yA8kKOmAlpsSeMyIyQ1F1QQm1GypBYIKdEmDC6XQF94ENx2p+PE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=HrHbtjhL; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="HrHbtjhL" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B35F31F000C4; Sat, 17 Oct 2026 16:18:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1792253906; bh=upB3XXscFaJ/05d/rSIFJFnPjwumWuFRpJb3mTq1x2A=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=HrHbtjhLHlQ3RL69TXanjTFTFEso3AAXsxmCaiSJmJ3plls/BopW66ZaePCKhp0MV BvK9k4qOI20kHgCO6OwjTQuDsJnM02qoKJg1/HQhmqyq+2SlTxaafJJAR0lbuTu9ro klCT+PJfEZYdFWLiG2XO1Ietd5d3fmkPAxgWNTtc= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Guillaume Gonnet , Alexei Starovoitov , Sasha Levin Subject: [PATCH 6.12 272/869] bpf: Fix tcx/netkit detach permissions when prog fd isnt given Date: Sat, 17 Oct 2026 17:51:53 +0200 Message-ID: <20261017160044.042880565@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261017160036.979869304@linuxfoundation.org> References: <20261017160036.979869304@linuxfoundation.org> User-Agent: quilt/0.69 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 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Guillaume Gonnet [ Upstream commit ae23bc81ddf7c17b663c4ed1b21e35527b0a7131 ] This commit fixes a security issue where BPF_PROG_DETACH on tcx or netkit devices could be executed by any user when no program fd was provided, bypassing permission checks. The fix adds a capability check for CAP_NET_ADMIN or CAP_SYS_ADMIN in this case. Fixes: e420bed02507 ("bpf: Add fd-based tcx multi-prog infra with link support") Signed-off-by: Guillaume Gonnet Link: https://lore.kernel.org/r/20260127160200.10395-1-ggonnet.linux@gmail.com Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin --- include/linux/bpf.h | 5 +++++ include/linux/bpf_mprog.h | 10 ++++++++++ kernel/bpf/syscall.c | 7 ++----- 3 files changed, 17 insertions(+), 5 deletions(-) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index a63fd54ac6b4f..8bdb4ba4df7ee 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -2999,6 +2999,11 @@ static inline void bpf_dynptr_set_rdonly(struct bpf_dynptr_kern *ptr) } #endif /* CONFIG_BPF_SYSCALL */ +static inline bool bpf_net_capable(void) +{ + return capable(CAP_NET_ADMIN) || capable(CAP_SYS_ADMIN); +} + static __always_inline int bpf_probe_read_kernel_common(void *dst, u32 size, const void *unsafe_ptr) { diff --git a/include/linux/bpf_mprog.h b/include/linux/bpf_mprog.h index 929225f7b0959..0b9f4caeeb0a3 100644 --- a/include/linux/bpf_mprog.h +++ b/include/linux/bpf_mprog.h @@ -340,4 +340,14 @@ static inline bool bpf_mprog_supported(enum bpf_prog_type type) return false; } } + +static inline bool bpf_mprog_detach_empty(enum bpf_prog_type type) +{ + switch (type) { + case BPF_PROG_TYPE_SCHED_CLS: + return bpf_net_capable(); + default: + return false; + } +} #endif /* __BPF_MPROG_H */ diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 857285a48d433..43081a7fb283a 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -1206,11 +1206,6 @@ static int map_check_btf(struct bpf_map *map, struct bpf_token *token, return ret; } -static bool bpf_net_capable(void) -{ - return capable(CAP_NET_ADMIN) || capable(CAP_SYS_ADMIN); -} - #define BPF_MAP_CREATE_LAST_FIELD map_token_fd /* called via syscall */ static int map_create(union bpf_attr *attr) @@ -4177,6 +4172,8 @@ static int bpf_prog_detach(const union bpf_attr *attr) prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype); if (IS_ERR(prog)) return PTR_ERR(prog); + } else if (!bpf_mprog_detach_empty(ptype)) { + return -EPERM; } } else if (is_cgroup_prog_type(ptype, 0, false)) { if (attr->attach_flags || attr->relative_fd) -- 2.53.0