| Message ID | 20231010-strncpy-drivers-net-ethernet-marvell-mvpp2-mvpp2_main-c-v1-1-51be96ad0324@google.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | fda9e465a9d92f59cae40d0c2a2450797db6ec66 |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | net: mvpp2: replace deprecated strncpy with strscpy | expand |
On Tue, Oct 10, 2023 at 09:24:42PM +0000, 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 `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> Yup, direct replacement. Reviewed-by: Kees Cook <keescook@chromium.org>
Hello: This patch was applied to netdev/net-next.git (main) by Jakub Kicinski <kuba@kernel.org>: On Tue, 10 Oct 2023 21:24:42 +0000 you 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 `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 */ > > [...] Here is the summary with links: - net: mvpp2: replace deprecated strncpy with strscpy https://git.kernel.org/netdev/net-next/c/fda9e465a9d9 You are awesome, thank you!
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)
`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(-) --- base-commit: cbf3a2cb156a2c911d8f38d8247814b4c07f49a2 change-id: 20231010-strncpy-drivers-net-ethernet-marvell-mvpp2-mvpp2_main-c-e9743cf1cf8f Best regards, -- Justin Stitt <justinstitt@google.com>