On Wed, Dec 11, 2019 at 08:01:09AM +0000, Andrey Zhizhikin wrote: > 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@xxxxxxxxxxxxxxxxxxxx> > Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> > Cc: Jiri Olsa <jolsa@xxxxxxxxxx> Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx> thanks, jirka > --- > 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; > } > > -- > 2.17.1 >
