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From: Christoph Hellwig <hch@lst.de>
To: x86@kernel.org, Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Masami Hiramatsu <mhiramat@kernel.org>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Andrew Morton <akpm@linux-foundation.org>
Cc: linux-parisc@vger.kernel.org, linux-um@lists.infradead.org,
	netdev@vger.kernel.org, bpf@vger.kernel.org, linux-mm@kvack.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH 12/23] bpf: handle the compat string in bpf_trace_copy_string better
Date: Thu, 21 May 2020 17:22:50 +0200	[thread overview]
Message-ID: <20200521152301.2587579-13-hch@lst.de> (raw)
In-Reply-To: <20200521152301.2587579-1-hch@lst.de>

User the proper helper for kernel or userspace addresses based on
TASK_SIZE instead of the dangerous strncpy_from_unsafe function.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 kernel/trace/bpf_trace.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 9d4080590f711..737d739230a6b 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -331,8 +331,11 @@ static void bpf_trace_copy_string(char *buf, void *unsafe_ptr, char fmt_ptype,
 	switch (fmt_ptype) {
 	case 's':
 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
-		strncpy_from_unsafe(buf, unsafe_ptr, bufsz);
-		break;
+		if ((unsigned long)unsafe_ptr < TASK_SIZE) {
+			strncpy_from_user_nofault(buf, user_ptr, bufsz);
+			break;
+		}
+		fallthrough;
 #endif
 	case 'k':
 		strncpy_from_kernel_nofault(buf, unsafe_ptr, bufsz);
-- 
2.26.2


WARNING: multiple messages have this Message-ID (diff)
From: Christoph Hellwig <hch@lst.de>
To: x86@kernel.org, Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Masami Hiramatsu <mhiramat@kernel.org>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Andrew Morton <akpm@linux-foundation.org>
Cc: linux-parisc@vger.kernel.org, netdev@vger.kernel.org,
	linux-um@lists.infradead.org, linux-kernel@vger.kernel.org,
	linux-mm@kvack.org, bpf@vger.kernel.org
Subject: [PATCH 12/23] bpf: handle the compat string in bpf_trace_copy_string better
Date: Thu, 21 May 2020 17:22:50 +0200	[thread overview]
Message-ID: <20200521152301.2587579-13-hch@lst.de> (raw)
In-Reply-To: <20200521152301.2587579-1-hch@lst.de>

User the proper helper for kernel or userspace addresses based on
TASK_SIZE instead of the dangerous strncpy_from_unsafe function.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 kernel/trace/bpf_trace.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 9d4080590f711..737d739230a6b 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -331,8 +331,11 @@ static void bpf_trace_copy_string(char *buf, void *unsafe_ptr, char fmt_ptype,
 	switch (fmt_ptype) {
 	case 's':
 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
-		strncpy_from_unsafe(buf, unsafe_ptr, bufsz);
-		break;
+		if ((unsigned long)unsafe_ptr < TASK_SIZE) {
+			strncpy_from_user_nofault(buf, user_ptr, bufsz);
+			break;
+		}
+		fallthrough;
 #endif
 	case 'k':
 		strncpy_from_kernel_nofault(buf, unsafe_ptr, bufsz);
-- 
2.26.2


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  parent reply	other threads:[~2020-05-21 15:23 UTC|newest]

Thread overview: 80+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-05-21 15:22 clean up and streamline probe_kernel_* and friends v4 Christoph Hellwig
2020-05-21 15:22 ` Christoph Hellwig
2020-05-21 15:22 ` [PATCH 01/23] maccess: unexport probe_kernel_write and probe_user_write Christoph Hellwig
2020-05-21 15:22   ` Christoph Hellwig
2020-05-21 15:22 ` [PATCH 02/23] maccess: remove various unused weak aliases Christoph Hellwig
2020-05-21 15:22   ` Christoph Hellwig
2020-05-21 15:22 ` [PATCH 03/23] maccess: remove duplicate kerneldoc comments Christoph Hellwig
2020-05-21 15:22   ` Christoph Hellwig
2020-05-21 15:22 ` [PATCH 04/23] maccess: clarify " Christoph Hellwig
2020-05-21 15:22   ` Christoph Hellwig
2020-05-21 15:22 ` [PATCH 05/23] maccess: update the top of file comment Christoph Hellwig
2020-05-21 15:22   ` Christoph Hellwig
2020-05-21 15:22 ` [PATCH 06/23] maccess: rename strncpy_from_unsafe_user to strncpy_from_user_nofault Christoph Hellwig
2020-05-21 15:22   ` Christoph Hellwig
2020-05-21 15:22 ` [PATCH 07/23] maccess: rename strncpy_from_unsafe_strict to strncpy_from_kernel_nofault Christoph Hellwig
2020-05-21 15:22   ` Christoph Hellwig
2020-05-21 15:22 ` [PATCH 08/23] maccess: rename strnlen_unsafe_user to strnlen_user_nofault Christoph Hellwig
2020-05-21 15:22   ` Christoph Hellwig
2020-05-21 15:22 ` [PATCH 09/23] maccess: remove probe_read_common and probe_write_common Christoph Hellwig
2020-05-21 15:22   ` Christoph Hellwig
2020-05-21 15:22 ` [PATCH 10/23] maccess: unify the probe kernel arch hooks Christoph Hellwig
2020-05-21 15:22   ` Christoph Hellwig
2020-05-28  0:55   ` Andrew Morton
2020-05-28  0:55     ` Andrew Morton
2020-05-21 15:22 ` [PATCH 11/23] bpf: factor out a bpf_trace_copy_string helper Christoph Hellwig
2020-05-21 15:22   ` Christoph Hellwig
2020-05-21 22:10   ` Andrii Nakryiko
2020-05-21 22:10     ` Andrii Nakryiko
2020-05-21 22:10     ` Andrii Nakryiko
2020-05-21 15:22 ` Christoph Hellwig [this message]
2020-05-21 15:22   ` [PATCH 12/23] bpf: handle the compat string in bpf_trace_copy_string better Christoph Hellwig
2020-05-21 22:10   ` Andrii Nakryiko
2020-05-21 22:10     ` Andrii Nakryiko
2020-05-21 22:10     ` Andrii Nakryiko
2020-05-28  2:04   ` Andrew Morton
2020-05-28  2:04     ` Andrew Morton
2020-05-28  2:26     ` Yonghong Song
2020-05-28  2:26       ` Yonghong Song
2020-05-28  4:39       ` Christoph Hellwig
2020-05-28  4:39         ` Christoph Hellwig
2020-05-28 17:06         ` Yonghong Song
2020-05-28 17:06           ` Yonghong Song
2020-05-21 15:22 ` [PATCH 13/23] bpf: rework the compat kernel probe handling Christoph Hellwig
2020-05-21 15:22   ` Christoph Hellwig
2020-05-21 22:10   ` Andrii Nakryiko
2020-05-21 22:10     ` Andrii Nakryiko
2020-05-21 22:10     ` Andrii Nakryiko
2020-05-21 15:22 ` [PATCH 14/23] tracing/kprobes: handle mixed kernel/userspace probes better Christoph Hellwig
2020-05-21 15:22   ` Christoph Hellwig
2020-05-22  0:04   ` Masami Hiramatsu
2020-05-22  0:04     ` Masami Hiramatsu
2020-05-21 15:22 ` [PATCH 15/23] maccess: remove strncpy_from_unsafe Christoph Hellwig
2020-05-21 15:22   ` Christoph Hellwig
2020-05-21 15:22 ` [PATCH 16/23] maccess: always use strict semantics for probe_kernel_read Christoph Hellwig
2020-05-21 15:22   ` Christoph Hellwig
2020-05-21 15:22 ` [PATCH 17/23] maccess: move user access routines together Christoph Hellwig
2020-05-21 15:22   ` Christoph Hellwig
2020-05-21 15:22 ` [PATCH 18/23] maccess: allow architectures to provide kernel probing directly Christoph Hellwig
2020-05-21 15:22   ` Christoph Hellwig
2020-05-21 15:22 ` [PATCH 19/23] x86: use non-set_fs based maccess routines Christoph Hellwig
2020-05-21 15:22   ` Christoph Hellwig
2020-05-21 15:22 ` [PATCH 20/23] maccess: rename probe_kernel_{read,write} to copy_{from,to}_kernel_nofault Christoph Hellwig
2020-05-21 15:22   ` [PATCH 20/23] maccess: rename probe_kernel_{read, write} to copy_{from, to}_kernel_nofault Christoph Hellwig
2020-05-21 15:22 ` [PATCH 21/23] maccess: rename probe_user_{read,write} to copy_{from,to}_user_nofault Christoph Hellwig
2020-05-21 15:22   ` [PATCH 21/23] maccess: rename probe_user_{read, write} to copy_{from, to}_user_nofault Christoph Hellwig
2020-05-21 15:23 ` [PATCH 22/23] maccess: rename probe_kernel_address to get_kernel_nofault Christoph Hellwig
2020-05-21 15:23   ` Christoph Hellwig
2020-05-21 15:23 ` [PATCH 23/23] maccess: return -ERANGE when copy_from_kernel_nofault_allowed fails Christoph Hellwig
2020-05-21 15:23   ` Christoph Hellwig
2020-05-21 18:03 ` clean up and streamline probe_kernel_* and friends v4 Linus Torvalds
2020-05-21 18:03   ` Linus Torvalds
2020-05-21 18:03   ` Linus Torvalds
2020-05-22  0:22 ` Masami Hiramatsu
2020-05-22  0:22   ` Masami Hiramatsu
2020-05-25 22:19 ` Andrew Morton
2020-05-25 22:19   ` Andrew Morton
2020-05-26  6:13   ` Christoph Hellwig
2020-05-26  6:13     ` Christoph Hellwig
2020-05-28  0:36     ` Andrew Morton
2020-05-28  0:36       ` Andrew Morton

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