[ 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@xxxxxxxxxxxxxxx # 4.9+
Signed-off-by: Artem Chernyshev <artem.chernyshev@xxxxxxxxxxx>
Reviewed-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
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 4fff0067bd2a..c498d5e164eb 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
