* [PATCH 4.4 051/113] tools lib api fs: Fix gcc9 stringop-truncation compilation error
[not found] <20200227132211.791484803@linuxfoundation.org>
@ 2020-02-27 13:36 ` Greg Kroah-Hartman
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From: Greg Kroah-Hartman @ 2020-02-27 13:36 UTC (permalink / raw)
To: linux-kernel
Cc: Greg Kroah-Hartman, stable, Andrey Zhizhikin, Petr Mladek,
Jiri Olsa, Alexei Starovoitov, Andrii Nakryiko, Daniel Borkmann,
Kefeng Wang, Martin KaFai Lau, Sergey Senozhatsky, Song Liu,
Yonghong Song, bpf, netdev, Arnaldo Carvalho de Melo, Sasha Levin
From: Andrey Zhizhikin <andrey.z@gmail.com>
[ Upstream commit 6794200fa3c9c3e6759dae099145f23e4310f4f7 ]
GCC9 introduced string hardening mechanisms, which exhibits the error
during fs api compilation:
error: '__builtin_strncpy' specified bound 4096 equals destination size
[-Werror=stringop-truncation]
This comes when the length of copy passed to strncpy is is equal to
destination size, which could potentially lead to buffer overflow.
There is a need to mitigate this potential issue by limiting the size of
destination by 1 and explicitly terminate the destination with NULL.
Signed-off-by: Andrey Zhizhikin <andrey.zhizhikin@leica-geosystems.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrii Nakryiko <andriin@fb.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Yonghong Song <yhs@fb.com>
Cc: bpf@vger.kernel.org
Cc: netdev@vger.kernel.org
Link: http://lore.kernel.org/lkml/20191211080109.18765-1-andrey.zhizhikin@leica-geosystems.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
tools/lib/api/fs/fs.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/tools/lib/api/fs/fs.c b/tools/lib/api/fs/fs.c
index 459599d1b6c41..58f05748dd39e 100644
--- a/tools/lib/api/fs/fs.c
+++ b/tools/lib/api/fs/fs.c
@@ -179,6 +179,7 @@ static bool fs__env_override(struct fs *fs)
size_t name_len = strlen(fs->name);
/* name + "_PATH" + '\0' */
char upper_name[name_len + 5 + 1];
+
memcpy(upper_name, fs->name, name_len);
mem_toupper(upper_name, name_len);
strcpy(&upper_name[name_len], "_PATH");
@@ -188,7 +189,8 @@ static bool fs__env_override(struct fs *fs)
return false;
fs->found = true;
- strncpy(fs->path, override_path, sizeof(fs->path));
+ strncpy(fs->path, override_path, sizeof(fs->path) - 1);
+ fs->path[sizeof(fs->path) - 1] = '\0';
return true;
}
--
2.20.1
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