lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <20240905075622.66819-5-lulie@linux.alibaba.com>
Date: Thu,  5 Sep 2024 15:56:21 +0800
From: Philo Lu <lulie@...ux.alibaba.com>
To: bpf@...r.kernel.org
Cc: edumazet@...gle.com,
	rostedt@...dmis.org,
	mhiramat@...nel.org,
	mathieu.desnoyers@...icios.com,
	martin.lau@...ux.dev,
	ast@...nel.org,
	daniel@...earbox.net,
	andrii@...nel.org,
	eddyz87@...il.com,
	song@...nel.org,
	yonghong.song@...ux.dev,
	john.fastabend@...il.com,
	kpsingh@...nel.org,
	sdf@...ichev.me,
	haoluo@...gle.com,
	jolsa@...nel.org,
	davem@...emloft.net,
	kuba@...nel.org,
	pabeni@...hat.com,
	mykolal@...com,
	shuah@...nel.org,
	mcoquelin.stm32@...il.com,
	alexandre.torgue@...s.st.com,
	thinker.li@...il.com,
	juntong.deng@...look.com,
	jrife@...gle.com,
	alan.maguire@...cle.com,
	davemarchevsky@...com,
	dxu@...uu.xyz,
	vmalik@...hat.com,
	cupertino.miranda@...cle.com,
	mattbobrowski@...gle.com,
	xuanzhuo@...ux.alibaba.com,
	netdev@...r.kernel.org,
	linux-trace-kernel@...r.kernel.org
Subject: [PATCH bpf-next v2 4/5] bpf: Allow bpf_dynptr_from_skb() for tp_btf

Making tp_btf able to use bpf_dynptr_from_skb(), which is useful for skb
parsing, especially for non-linear paged skb data. This is achieved by
adding KF_TRUSTED_ARGS flag to bpf_dynptr_from_skb and registering it
for TRACING progs. With KF_TRUSTED_ARGS, args from fentry/fexit are
excluded, so that unsafe progs like fexit/__kfree_skb are not allowed.

We also need the skb dynptr to be read-only in tp_btf. Because
may_access_direct_pkt_data() returns false by default when checking
bpf_dynptr_from_skb, there is no need to add BPF_PROG_TYPE_TRACING to it
explicitly.

Suggested-by: Martin KaFai Lau <martin.lau@...ux.dev>
Signed-off-by: Philo Lu <lulie@...ux.alibaba.com>
---
 net/core/filter.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/core/filter.c b/net/core/filter.c
index 6d4fa9198b652..4c01f4756ddb5 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -12074,7 +12074,7 @@ int bpf_dynptr_from_skb_rdonly(struct __sk_buff *skb, u64 flags,
 }
 
 BTF_KFUNCS_START(bpf_kfunc_check_set_skb)
-BTF_ID_FLAGS(func, bpf_dynptr_from_skb)
+BTF_ID_FLAGS(func, bpf_dynptr_from_skb, KF_TRUSTED_ARGS)
 BTF_KFUNCS_END(bpf_kfunc_check_set_skb)
 
 BTF_KFUNCS_START(bpf_kfunc_check_set_xdp)
@@ -12123,6 +12123,7 @@ static int __init bpf_kfunc_init(void)
 	ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_LWT_XMIT, &bpf_kfunc_set_skb);
 	ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_LWT_SEG6LOCAL, &bpf_kfunc_set_skb);
 	ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_NETFILTER, &bpf_kfunc_set_skb);
+	ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING, &bpf_kfunc_set_skb);
 	ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_XDP, &bpf_kfunc_set_xdp);
 	ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
 					       &bpf_kfunc_set_sock_addr);
-- 
2.32.0.3.g01195cf9f


Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ