bpf.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
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


  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

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200515101118.6508-3-daniel@iogearbox.net \
    --to=daniel@iogearbox.net \
    --cc=ast@kernel.org \
    --cc=bpf@vger.kernel.org \
    --cc=brendan.d.gregg@gmail.com \
    --cc=hch@lst.de \
    --cc=john.fastabend@gmail.com \
    --cc=mhiramat@kernel.org \
    --cc=netdev@vger.kernel.org \
    --cc=torvalds@linux-foundation.org \
    --cc=yhs@fb.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).