[PATCH] drbd: Replace deprecated strcpy with strscpy

[PATCH] drbd: Replace deprecated strcpy with strscpy

[Thorsten Blum]

strcpy() has been deprecated [1] because it performs no bounds checking
on the destination buffer, which can lead to buffer overflows. Replace
it with the safer strscpy().  No functional changes.

Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strcpy [1]
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
---
 drivers/block/drbd/drbd_main.c     | 14 +++++++++-----
 drivers/block/drbd/drbd_receiver.c |  4 ++--
 2 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index c73376886e7a..8cb5d5ba9a3d 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -32,6 +32,7 @@
 #include <linux/memcontrol.h>
 #include <linux/mm_inline.h>
 #include <linux/slab.h>
+#include <linux/string.h>
 #include <linux/random.h>
 #include <linux/reboot.h>
 #include <linux/notifier.h>
@@ -732,9 +733,9 @@ int drbd_send_sync_param(struct drbd_peer_device *peer_device)
 	}
 
 	if (apv >= 88)
-		strcpy(p->verify_alg, nc->verify_alg);
+		strscpy(p->verify_alg, nc->verify_alg);
 	if (apv >= 89)
-		strcpy(p->csums_alg, nc->csums_alg);
+		strscpy(p->csums_alg, nc->csums_alg);
 	rcu_read_unlock();
 
 	return drbd_send_command(peer_device, sock, cmd, size, NULL, 0);
@@ -745,6 +746,7 @@ int __drbd_send_protocol(struct drbd_connection *connection, enum drbd_packet cm
 	struct drbd_socket *sock;
 	struct p_protocol *p;
 	struct net_conf *nc;
+	size_t integrity_alg_len;
 	int size, cf;
 
 	sock = &connection->data;
@@ -762,8 +764,10 @@ int __drbd_send_protocol(struct drbd_connection *connection, enum drbd_packet cm
 	}
 
 	size = sizeof(*p);
-	if (connection->agreed_pro_version >= 87)
-		size += strlen(nc->integrity_alg) + 1;
+	if (connection->agreed_pro_version >= 87) {
+		integrity_alg_len = strlen(nc->integrity_alg) + 1;
+		size += integrity_alg_len;
+	}
 
 	p->protocol      = cpu_to_be32(nc->wire_protocol);
 	p->after_sb_0p   = cpu_to_be32(nc->after_sb_0p);
@@ -778,7 +782,7 @@ int __drbd_send_protocol(struct drbd_connection *connection, enum drbd_packet cm
 	p->conn_flags    = cpu_to_be32(cf);
 
 	if (connection->agreed_pro_version >= 87)
-		strcpy(p->integrity_alg, nc->integrity_alg);
+		strscpy(p->integrity_alg, nc->integrity_alg, integrity_alg_len);
 	rcu_read_unlock();
 
 	return __conn_send_command(connection, sock, cmd, size, NULL, 0);
diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
index 3de919b6f0e1..3d0a061b6c40 100644
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -3801,14 +3801,14 @@ static int receive_SyncParam(struct drbd_connection *connection, struct packet_i
 			*new_net_conf = *old_net_conf;
 
 			if (verify_tfm) {
-				strcpy(new_net_conf->verify_alg, p->verify_alg);
+				strscpy(new_net_conf->verify_alg, p->verify_alg);
 				new_net_conf->verify_alg_len = strlen(p->verify_alg) + 1;
 				crypto_free_shash(peer_device->connection->verify_tfm);
 				peer_device->connection->verify_tfm = verify_tfm;
 				drbd_info(device, "using verify-alg: \"%s\"\n", p->verify_alg);
 			}
 			if (csums_tfm) {
-				strcpy(new_net_conf->csums_alg, p->csums_alg);
+				strscpy(new_net_conf->csums_alg, p->csums_alg);
 				new_net_conf->csums_alg_len = strlen(p->csums_alg) + 1;
 				crypto_free_shash(peer_device->connection->csums_tfm);
 				peer_device->connection->csums_tfm = csums_tfm;
-- 
Thorsten Blum <thorsten.blum@linux.dev>
GPG: 1D60 735E 8AEF 3BE4 73B6  9D84 7336 78FD 8DFE EAD4

Re: [PATCH] drbd: Replace deprecated strcpy with strscpy

[Christoph Böhmwalder]

On 1/12/26 18:04, Thorsten Blum wrote:
> strcpy() has been deprecated [1] because it performs no bounds checking
> on the destination buffer, which can lead to buffer overflows. Replace
> it with the safer strscpy().  No functional changes.
> 
> Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strcpy [1]
> Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
> ---
>   drivers/block/drbd/drbd_main.c     | 14 +++++++++-----
>   drivers/block/drbd/drbd_receiver.c |  4 ++--
>   2 files changed, 11 insertions(+), 7 deletions(-)

Looks good, thanks.

Reviewed-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com>

Re: [PATCH] drbd: Replace deprecated strcpy with strscpy

[Jens Axboe]

On Mon, 12 Jan 2026 18:04:12 +0100, Thorsten Blum wrote:
> strcpy() has been deprecated [1] because it performs no bounds checking
> on the destination buffer, which can lead to buffer overflows. Replace
> it with the safer strscpy().  No functional changes.
> 
> 

Applied, thanks!

[1/1] drbd: Replace deprecated strcpy with strscpy
      commit: 81b1f046ff8a5ad5da2c970cff354b61dfa1d6b1

Best regards,
-- 
Jens Axboe