On 19/03/21 2:33 am, Eric Biggers wrote:
On Thu, Mar 18, 2021 at 07:03:04PM +0530, Shreeya Patel wrote:
Following warning was reported by Kernel Test Robot.
In function 'utf8_parse_version',
inlined from 'utf8_load' at fs/unicode/utf8mod.c:195:7:
fs/unicode/utf8mod.c:175:2: warning: 'strncpy' specified bound 12 equals
destination size [-Wstringop-truncation]
175 | strncpy(version_string, version, sizeof(version_string));
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The -Wstringop-truncation warning highlights the unintended
uses of the strncpy function that truncate the terminating NULL
character from the source string.
Unlike strncpy(), strscpy() always null-terminates the destination string,
hence use strscpy() instead of strncpy().
Signed-off-by: Shreeya Patel <shreeya.patel@xxxxxxxxxxxxx>
Reported-by: kernel test robot <lkp@xxxxxxxxx>
---
Changes in v2
- Resolve warning of -Wstringop-truncation reported by
kernel test robot.
fs/unicode/unicode-core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/unicode/unicode-core.c b/fs/unicode/unicode-core.c
index d5f09e022ac5..287a8a48836c 100644
--- a/fs/unicode/unicode-core.c
+++ b/fs/unicode/unicode-core.c
@@ -179,7 +179,7 @@ static int unicode_parse_version(const char *version, unsigned int *maj,
{0, NULL}
};
- strncpy(version_string, version, sizeof(version_string));
+ strscpy(version_string, version, sizeof(version_string));
Shouldn't unicode_parse_version() return an error if the string gets truncated
here? I.e. check if strscpy() returns < 0.
Also, this is a "fix" (though one that doesn't currently matter, since 'version'
is currently always shorter than sizeof(version_string)), so it should go first
in the series and have a Fixes tag.
Thanks Eric, will send v3 for it.
- Eric
