From: Gil Portnoy Date: Fri, 10 Jul 2026 11:27:10 +0000 (+0900) Subject: ksmbd: fix memory leak of xattr_stream_name in smb2_rename() X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=08b9452a338db7b7f9560342a1fff30f7a58a226;p=thirdparty%2Fkernel%2Flinux.git ksmbd: fix memory leak of xattr_stream_name in smb2_rename() On an SMB2 SET_INFO(FileRenameInformation) whose target names an alternate data stream, smb2_rename() obtains a formatted stream-name string from ksmbd_vfs_xattr_stream_name(), which allocates it with kasprintf() and returns it through an out-param: rc = ksmbd_vfs_xattr_stream_name(stream_name, &xattr_stream_name, ...); if (rc) goto out; rc = ksmbd_vfs_setxattr(..., xattr_stream_name, ...); if (rc < 0) { ... goto out; } goto out; xattr_stream_name is declared inside the alternate-data-stream block, but the out: label is outside that block and frees only new_name, so it cannot release xattr_stream_name. ksmbd_vfs_setxattr() takes a const char * and only reads the name, so it does not take ownership either. Both the setxattr-failure and the success path therefore leak the kasprintf()'d string. An authenticated client with a writable share can leak kernel memory on every stream rename, exhausting kernel memory over time. Free xattr_stream_name after its use, before the block's goto out. The two earlier goto out paths never assign the variable, so there is no double-free. Signed-off-by: Gil Portnoy Acked-by: Namjae Jeon Signed-off-by: Steve French --- diff --git a/fs/smb/server/smb2pdu.c b/fs/smb/server/smb2pdu.c index c407425cbba0..c8acf9f04e45 100644 --- a/fs/smb/server/smb2pdu.c +++ b/fs/smb/server/smb2pdu.c @@ -6597,9 +6597,8 @@ static int smb2_rename(struct ksmbd_work *work, pr_err("failed to store stream name in xattr: %d\n", rc); rc = -EINVAL; - goto out; } - + kfree(xattr_stream_name); goto out; }