--- /dev/null
+From 4f71dbe0ec5b9123a9a46e167332ad5a820a74e2 Mon Sep 17 00:00:00 2001
+From: Sasha Levin <sashal@kernel.org>
+Date: Wed, 4 Jan 2023 11:14:45 -0500
+Subject: btrfs: replace strncpy() with strscpy()
+
+[ Upstream commit 63d5429f68a3d4c4aa27e65a05196c17f86c41d6 ]
+
+Using strncpy() on NUL-terminated strings are deprecated. To avoid
+possible forming of non-terminated string strscpy() should be used.
+
+Found by Linux Verification Center (linuxtesting.org) with SVACE.
+
+CC: stable@vger.kernel.org # 4.9+
+Signed-off-by: Artem Chernyshev <artem.chernyshev@red-soft.ru>
+Reviewed-by: David Sterba <dsterba@suse.com>
+Signed-off-by: David Sterba <dsterba@suse.com>
+Signed-off-by: Sasha Levin <sashal@kernel.org>
+---
+ fs/btrfs/ioctl.c | 9 +++------
+ fs/btrfs/rcu-string.h | 6 +++++-
+ 2 files changed, 8 insertions(+), 7 deletions(-)
+
+diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
+index 5ba2e810dc6e..fd1902573cde 100644
+--- a/fs/btrfs/ioctl.c
++++ b/fs/btrfs/ioctl.c
+@@ -3750,13 +3750,10 @@ static long btrfs_ioctl_dev_info(struct btrfs_fs_info *fs_info,
+ di_args->bytes_used = btrfs_device_get_bytes_used(dev);
+ di_args->total_bytes = btrfs_device_get_total_bytes(dev);
+ memcpy(di_args->uuid, dev->uuid, sizeof(di_args->uuid));
+- if (dev->name) {
+- strncpy(di_args->path, rcu_str_deref(dev->name),
+- sizeof(di_args->path) - 1);
+- di_args->path[sizeof(di_args->path) - 1] = 0;
+- } else {
++ if (dev->name)
++ strscpy(di_args->path, rcu_str_deref(dev->name), sizeof(di_args->path));
++ else
+ di_args->path[0] = '\0';
+- }
+
+ out:
+ rcu_read_unlock();
+diff --git a/fs/btrfs/rcu-string.h b/fs/btrfs/rcu-string.h
+index 5c1a617eb25d..5c2b66d155ef 100644
+--- a/fs/btrfs/rcu-string.h
++++ b/fs/btrfs/rcu-string.h
+@@ -18,7 +18,11 @@ static inline struct rcu_string *rcu_string_strdup(const char *src, gfp_t mask)
+ (len * sizeof(char)), mask);
+ if (!ret)
+ return ret;
+- strncpy(ret->str, src, len);
++ /* Warn if the source got unexpectedly truncated. */
++ if (WARN_ON(strscpy(ret->str, src, len) < 0)) {
++ kfree(ret);
++ return NULL;
++ }
+ return ret;
+ }
+
+--
+2.35.1
+