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Subject[PATCH] net: mvpp2: replace deprecated strncpy with strscpy
From
`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 `irqname` to be NUL-terminated based on its use with
of_irq_get_byname() -> of_property_match_string() wherein it is used
with a format string and a `strcmp`:
| pr_debug("comparing %s with %s\n", string, p);
| if (strcmp(string, p) == 0)
| return i; /* Found it; return index */

NUL-padding is not required as is evident by other assignments to
`irqname` which do not NUL-pad:
| if (port->flags & MVPP2_F_DT_COMPAT)
| snprintf(irqname, sizeof(irqname), "tx-cpu%d", i);
| else
| snprintf(irqname, sizeof(irqname), "hif%d", i);

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.

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@vger.kernel.org
Signed-off-by: Justin Stitt <justinstitt@google.com>
---
Note: build-tested only.
---
drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
index 21c3f9b015c8..331dba2ae13d 100644
--- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
+++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
@@ -5831,7 +5831,7 @@ static int mvpp2_multi_queue_vectors_init(struct mvpp2_port *port,
v->type = MVPP2_QUEUE_VECTOR_SHARED;

if (port->flags & MVPP2_F_DT_COMPAT)
- strncpy(irqname, "rx-shared", sizeof(irqname));
+ strscpy(irqname, "rx-shared", sizeof(irqname));
}

if (port_node)
---
base-commit: cbf3a2cb156a2c911d8f38d8247814b4c07f49a2
change-id: 20231010-strncpy-drivers-net-ethernet-marvell-mvpp2-mvpp2_main-c-e9743cf1cf8f
Best regards,
--
Justin Stitt <justinstitt@google.com>

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