From: Daniel Borkmann <daniel@iogearbox.net>
To: ast@kernel.org
Cc: bpf@vger.kernel.org, netdev@vger.kernel.org,
torvalds@linux-foundation.org, mhiramat@kernel.org,
brendan.d.gregg@gmail.com, hch@lst.de, john.fastabend@gmail.com,
yhs@fb.com, Daniel Borkmann <daniel@iogearbox.net>
Subject: [PATCH bpf v2 2/3] bpf: add bpf_probe_read_{user, kernel}_str() to do_refine_retval_range
Date: Fri, 15 May 2020 12:11:17 +0200 [thread overview]
Message-ID: <20200515101118.6508-3-daniel@iogearbox.net> (raw)
In-Reply-To: <20200515101118.6508-1-daniel@iogearbox.net>
Given bpf_probe_read{,str}() BPF helpers are now only available under
CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE, we need to add the drop-in
replacements of bpf_probe_read_{kernel,user}_str() to do_refine_retval_range()
as well to avoid hitting the same issue as in 849fa50662fbc ("bpf/verifier:
refine retval R0 state for bpf_get_stack helper").
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Yonghong Song <yhs@fb.com>
---
kernel/bpf/verifier.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index fa1d8245b925..ac922b0d3b00 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -4340,7 +4340,9 @@ static void do_refine_retval_range(struct bpf_reg_state *regs, int ret_type,
if (ret_type != RET_INTEGER ||
(func_id != BPF_FUNC_get_stack &&
- func_id != BPF_FUNC_probe_read_str))
+ func_id != BPF_FUNC_probe_read_str &&
+ func_id != BPF_FUNC_probe_read_kernel_str &&
+ func_id != BPF_FUNC_probe_read_user_str))
return;
ret_reg->smax_value = meta->msize_max_value;
--
2.21.0
next prev parent reply other threads:[~2020-05-15 10:11 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-15 10:11 [PATCH bpf v2 0/3] Restrict bpf_probe_read{,str}() and bpf_trace_printk()'s %s Daniel Borkmann
2020-05-15 10:11 ` [PATCH bpf v2 1/3] bpf: restrict bpf_probe_read{,str}() only to archs where they work Daniel Borkmann
2020-05-15 10:11 ` Daniel Borkmann [this message]
2020-05-15 10:11 ` [PATCH bpf v2 3/3] bpf: restrict bpf_trace_printk()'s %s usage and add %pks, %pus specifier Daniel Borkmann
2020-05-15 15:18 ` [PATCH bpf v2 0/3] Restrict bpf_probe_read{,str}() and bpf_trace_printk()'s %s Alexei Starovoitov
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