From 9008eb85a2da44143ad7a0d80e102c418d61dcef Mon Sep 17 00:00:00 2001 From: Andrey Zhizhikin Date: Wed, 11 Dec 2019 08:01:09 +0000 Subject: tools lib api fs: Fix gcc9 stringop-truncation compilation error [ 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 Reviewed-by: Petr Mladek Acked-by: Jiri Olsa Cc: Alexei Starovoitov Cc: Andrii Nakryiko Cc: Daniel Borkmann Cc: Kefeng Wang Cc: Martin KaFai Lau Cc: Petr Mladek Cc: Sergey Senozhatsky Cc: Song Liu Cc: Yonghong Song 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 Signed-off-by: Sasha Levin --- tools/lib/api/fs/fs.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'tools') diff --git a/tools/lib/api/fs/fs.c b/tools/lib/api/fs/fs.c index f99f49e4a31e..21e714cf0126 100644 --- a/tools/lib/api/fs/fs.c +++ b/tools/lib/api/fs/fs.c @@ -194,6 +194,7 @@ 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"); @@ -203,7 +204,8 @@ 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; } -- cgit v1.2.3