On June 13, 2023 5:12:46 PM PDT, Azeem Shaikh <azeemshaikh38@xxxxxxxxx> wrote: >strlcpy() reads the entire source buffer first. >This read may exceed the destination size limit. >This is both inefficient and can lead to linear read >overflows if a source string is not NUL-terminated [1]. >In an effort to remove strlcpy() completely [2], replace >strlcpy() here with sysfs_emit(). > >Direct replacement is safe here since the getter in kernel_params_ops >handles -errno return [3]. > >[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy >[2] https://github.com/KSPP/linux/issues/89 >[3] https://elixir.bootlin.com/linux/v6.4-rc6/source/include/linux/moduleparam.h#L52 > >Signed-off-by: Azeem Shaikh <azeemshaikh38@xxxxxxxxx> >--- > net/sunrpc/svc.c | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) > >diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c >index e6d4cec61e47..77326f163801 100644 >--- a/net/sunrpc/svc.c >+++ b/net/sunrpc/svc.c >@@ -109,13 +109,13 @@ param_get_pool_mode(char *buf, const struct kernel_param *kp) > switch (*ip) > { > case SVC_POOL_AUTO: >- return strlcpy(buf, "auto\n", 20); >+ return sysfs_emit(buf, "auto\n"); > case SVC_POOL_GLOBAL: >- return strlcpy(buf, "global\n", 20); >+ return sysfs_emit(buf, "global\n"); > case SVC_POOL_PERCPU: >- return strlcpy(buf, "percpu\n", 20); >+ return sysfs_emit(buf, "percpu\n"); > case SVC_POOL_PERNODE: >- return strlcpy(buf, "pernode\n", 20); >+ return sysfs_emit(buf, "pernode\n"); > default: > return sprintf(buf, "%d\n", *ip); Please replace the sprintf too (and then the Subject could be "use sysfs_emit" or so). -Kees -- Kees Cook
