* [PATCH 08/20] tools lib api fs: Fix gcc9 stringop-truncation compilation error
[not found] <20200106160705.10899-1-acme@kernel.org>
@ 2020-01-06 16:06 ` Arnaldo Carvalho de Melo
2020-01-07 9:16 ` Petr Mladek
0 siblings, 1 reply; 2+ messages in thread
From: Arnaldo Carvalho de Melo @ 2020-01-06 16:06 UTC (permalink / raw)
To: Ingo Molnar, Thomas Gleixner
Cc: Jiri Olsa, Namhyung Kim, Clark Williams, linux-kernel,
linux-perf-users, Andrey Zhizhikin, Andrey Zhizhikin, Petr Mladek,
Alexei Starovoitov, Andrii Nakryiko, Daniel Borkmann, Kefeng Wang,
Martin KaFai Lau, Sergey Senozhatsky, Song Liu, Yonghong Song,
bpf, netdev, Arnaldo Carvalho de Melo
From: Andrey Zhizhikin <andrey.z@gmail.com>
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>
---
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 11b3885e833e..027b18f7ed8c 100644
--- a/tools/lib/api/fs/fs.c
+++ b/tools/lib/api/fs/fs.c
@@ -210,6 +210,7 @@ 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");
@@ -219,7 +220,8 @@ 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;
}
--
2.21.1
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