From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
bpf@vger.kernel.org, Daniel Borkmann <daniel@iogearbox.net>,
John Fastabend <john.fastabend@gmail.com>,
Benedict Schlueter <benedict.schlueter@rub.de>,
Piotr Krysiuk <piotras@gmail.com>,
Alexei Starovoitov <ast@kernel.org>,
Ovidiu Panait <ovidiu.panait@windriver.com>
Subject: [PATCH 4.19 03/11] bpf: Inherit expanded/patched seen count from old aux data
Date: Fri, 13 Aug 2021 17:07:10 +0200 [thread overview]
Message-ID: <20210813150520.181696817@linuxfoundation.org> (raw)
In-Reply-To: <20210813150520.072304554@linuxfoundation.org>
From: Daniel Borkmann <daniel@iogearbox.net>
commit d203b0fd863a2261e5d00b97f3d060c4c2a6db71 upstream.
Instead of relying on current env->pass_cnt, use the seen count from the
old aux data in adjust_insn_aux_data(), and expand it to the new range of
patched instructions. This change is valid given we always expand 1:n
with n>=1, so what applies to the old/original instruction needs to apply
for the replacement as well.
Not relying on env->pass_cnt is a prerequisite for a later change where we
want to avoid marking an instruction seen when verified under speculative
execution path.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: John Fastabend <john.fastabend@gmail.com>
Reviewed-by: Benedict Schlueter <benedict.schlueter@rub.de>
Reviewed-by: Piotr Krysiuk <piotras@gmail.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
[OP: - declare old_data as bool instead of u32 (struct bpf_insn_aux_data.seen
is bool in 5.4)
- adjusted context for 4.19]
Signed-off-by: Ovidiu Panait <ovidiu.panait@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
kernel/bpf/verifier.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -5690,6 +5690,7 @@ static int adjust_insn_aux_data(struct b
u32 off, u32 cnt)
{
struct bpf_insn_aux_data *new_data, *old_data = env->insn_aux_data;
+ bool old_seen = old_data[off].seen;
int i;
if (cnt == 1)
@@ -5701,8 +5702,10 @@ static int adjust_insn_aux_data(struct b
memcpy(new_data, old_data, sizeof(struct bpf_insn_aux_data) * off);
memcpy(new_data + off + cnt - 1, old_data + off,
sizeof(struct bpf_insn_aux_data) * (prog_len - off - cnt + 1));
- for (i = off; i < off + cnt - 1; i++)
- new_data[i].seen = true;
+ for (i = off; i < off + cnt - 1; i++) {
+ /* Expand insni[off]'s seen count to the patched range. */
+ new_data[i].seen = old_seen;
+ }
env->insn_aux_data = new_data;
vfree(old_data);
return 0;
next prev parent reply other threads:[~2021-08-13 15:14 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-13 15:07 [PATCH 4.19 00/11] 4.19.204-rc1 review Greg Kroah-Hartman
2021-08-13 15:07 ` [PATCH 4.19 01/11] KVM: SVM: Fix off-by-one indexing when nullifying last used SEV VMCB Greg Kroah-Hartman
2021-08-13 15:07 ` [PATCH 4.19 02/11] tracing: Reject string operand in the histogram expression Greg Kroah-Hartman
2021-08-13 15:07 ` Greg Kroah-Hartman [this message]
2021-08-13 15:07 ` [PATCH 4.19 04/11] bpf: Do not mark insn as seen under speculative path verification Greg Kroah-Hartman
2021-08-13 15:07 ` [PATCH 4.19 05/11] bpf: Fix leakage under speculation on mispredicted branches Greg Kroah-Hartman
2021-08-13 15:07 ` [PATCH 4.19 06/11] bpf, selftests: Adjust few selftest outcomes wrt unreachable code Greg Kroah-Hartman
2021-08-13 15:07 ` [PATCH 4.19 07/11] KVM: X86: MMU: Use the correct inherited permissions to get shadow page Greg Kroah-Hartman
2021-08-13 15:07 ` [PATCH 4.19 08/11] USB:ehci:fix Kunpeng920 ehci hardware problem Greg Kroah-Hartman
2021-08-13 15:07 ` [PATCH 4.19 09/11] ppp: Fix generating ppp unit id when ifname is not specified Greg Kroah-Hartman
2021-08-13 15:07 ` [PATCH 4.19 10/11] ovl: prevent private clone if bind mount is not allowed Greg Kroah-Hartman
2021-08-13 15:07 ` [PATCH 4.19 11/11] net: xilinx_emaclite: Do not print real IOMEM pointer Greg Kroah-Hartman
2021-08-13 23:25 ` [PATCH 4.19 00/11] 4.19.204-rc1 review Shuah Khan
2021-08-14 11:09 ` Sudip Mukherjee
2021-08-14 11:42 ` Naresh Kamboju
2021-08-14 18:15 ` Guenter Roeck
2021-08-15 19:50 ` Pavel Machek
2021-08-16 3:09 ` Samuel Zou
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