On 10/23/23 21:24, Justin Stitt wrote:
strncpy() is deprecated for use on NUL-terminated destination strings
[1] and as such we should prefer more robust and less ambiguous string
interfaces.
We expect both `params` and `id` to be NUL-terminated based on their
usage with format strings:
format_node_data(iuparams, iunodeid, &lir->incident_node);
format_node_data(auparams, aunodeid, &lir->attached_node);
switch (lir->iq.class) {
case LIR_IQ_CLASS_DEGRADED:
pr_warn("Link degraded: RS=%02x RSID=%04x IC=%02x "
"IUPARAMS=%s IUNODEID=%s AUPARAMS=%s AUNODEID=%s\n",
sei_area->rs, sei_area->rsid, lir->ic, iuparams,
iunodeid, auparams, aunodeid);
NUL-padding is not required as both `params` and `id` have been memset
to 0:
memset(params, 0, PARAMS_LEN);
memset(id, 0, NODEID_LEN);
Considering the above, a suitable replacement is `strscpy` [2] due to
the fact that it guarantees NUL-termination on the destination buffer
without unnecessarily NUL-padding.
Note that there's no overread bugs in the current implementation as the
string literal "n/a" has a size much smaller than PARAMS_LEN or
NODEID_LEN. Nonetheless, let's favor strscpy().
Link:https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
Link:https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2]
Link:https://github.com/KSPP/linux/issues/90
Cc:linux-hardening@xxxxxxxxxxxxxxx
Signed-off-by: Justin Stitt<justinstitt@xxxxxxxxxx>
LGTM. Thank you.
Reviewed-by: Vineeth Vijayan <vneethv@xxxxxxxxxxxxx>
I can push this to s390-tree and Heiko/Vasily will upstream it.
---snip---
