From: Haoxiang Li <haoxiang_li2024@163.com> stable inclusion from stable-v6.6.80 commit 9e5d99a4cf2e23c716b44862975548415fae5391 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IBSVZD CVE: CVE-2025-21844 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- commit 860ca5e50f73c2a1cef7eefc9d39d04e275417f7 upstream. Add check for the return value of cifs_buf_get() and cifs_small_buf_get() in receive_encrypted_standard() to prevent null pointer dereference. Fixes: eec04ea11969 ("smb: client: fix OOB in receive_encrypted_standard()") Cc: stable@vger.kernel.org Signed-off-by: Haoxiang Li <haoxiang_li2024@163.com> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Li Lingfeng <lilingfeng3@huawei.com> --- fs/smb/client/smb2ops.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/fs/smb/client/smb2ops.c b/fs/smb/client/smb2ops.c index fc6d00344c50..55269d3a8278 100644 --- a/fs/smb/client/smb2ops.c +++ b/fs/smb/client/smb2ops.c @@ -4904,6 +4904,10 @@ receive_encrypted_standard(struct TCP_Server_Info *server, next_buffer = (char *)cifs_buf_get(); else next_buffer = (char *)cifs_small_buf_get(); + if (!next_buffer) { + cifs_server_dbg(VFS, "No memory for (large) SMB response\n"); + return -1; + } memcpy(next_buffer, buf + next_cmd, pdu_length - next_cmd); } -- 2.31.1