block: Replace all non-returning strlcpy with strscpy

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 strscpy().
No return values were used, so direct replacement is safe.

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
[2] https://github.com/KSPP/linux/issues/89

Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20230530155608.272266-1-azeemshaikh38@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/block/blk-cgroup-fc-appid.c b/block/blk-cgroup-fc-appid.c
index 842e5e1c0f3cb97dafe6810dfbc527a30edb78ff..3ec21333f393b79a6650ff0f214f217fe666bed5 100644 (file)
--- a/block/blk-cgroup-fc-appid.c
+++ b/block/blk-cgroup-fc-appid.c
@@ -34,7 +34,7 @@ int blkcg_set_fc_appid(char *app_id, u64 cgrp_id, size_t app_id_len)
         * the vmid from the fabric.
         * Adding the overhead of a lock is not necessary.
         */
-       strlcpy(blkcg->fc_app_id, app_id, app_id_len);
+       strscpy(blkcg->fc_app_id, app_id, app_id_len);
        css_put(css);
 out_cgrp_put:
        cgroup_put(cgrp);

diff --git a/block/elevator.c b/block/elevator.c
index 24909069f872889506ce2b77313c5f8fd46b1c66..8400e303fbcbd6d4e0e4371aa990e021bedb24a6 100644 (file)
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -751,7 +751,7 @@ ssize_t elv_iosched_store(struct request_queue *q, const char *buf,
        if (!elv_support_iosched(q))
                return count;
 
-       strlcpy(elevator_name, buf, sizeof(elevator_name));
+       strscpy(elevator_name, buf, sizeof(elevator_name));
        ret = elevator_change(q, strstrip(elevator_name));
        if (!ret)
                return count;

diff --git a/block/genhd.c b/block/genhd.c
index 1cb489b927d50ab06a84a4bfd6913ca8ba7318d4..3537b7d7c484d7b3bf92ed0ddd629f9e9816e7a4 100644 (file)
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -253,7 +253,7 @@ int __register_blkdev(unsigned int major, const char *name,
 #ifdef CONFIG_BLOCK_LEGACY_AUTOLOAD
        p->probe = probe;
 #endif
-       strlcpy(p->name, name, sizeof(p->name));
+       strscpy(p->name, name, sizeof(p->name));
        p->next = NULL;
        index = major_to_index(major);