From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6A1FA1F893B; Tue, 3 Dec 2024 16:16:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733242617; cv=none; b=QfKMFSHy66NDSUCK4NzUexn99ik3eIFyIeAgrHk5/BsljsvlmBQyVH21p3E3LOhIjwNaWkIfzeu2qYELNy4RYq519r5X1BfBZgPKFN/YAtGim3FDWHJdbgCAAHRFcekTZVy+PR9xWjUf7bA4dDyGR+AxaeNwO7ip89ZMP+b8Tj4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733242617; c=relaxed/simple; bh=DNjoKT/GT+PIa7BYqi5WSQDCNrqH5bSqa5zcJURqyS4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=W/NFxWKK1MHpUblpAAWMy+cmJLa9NWHvjYhqnqqYHYuG9lyAVebsqxbki1yPcMcJmuy/2zzRGOFiif2zbk4zrPmq7sFZDXV3Q0EWBqsKRHYiEPF2LtIXtME8RQIWE4M5+b6l3WfyjjMPPeSEqgqnDQaG7fABPv8WymMM+JDgFG4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=ZRdzYulc; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="ZRdzYulc" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C9704C4CED6; Tue, 3 Dec 2024 16:16:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1733242617; bh=DNjoKT/GT+PIa7BYqi5WSQDCNrqH5bSqa5zcJURqyS4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZRdzYulcEc4Wm34dehh0wzfp1+bUkRhBF8FvC8/iX4nBUkJey4WOHVStpWn32Miq7 t/YHMti7tYUsgWRWh2wE2nVcofBxA/kaTHGz3I6lFgcTxrRy86WCFTrXC/mFcCf5R9 fcd7UiNsT/Hf3iYV3Ze1r8vuV0jB5BadfQEQ5Z+I= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jay Shin , "Paulo Alcantara (Red Hat)" , Steve French Subject: [PATCH 6.12 750/826] smb: client: fix use-after-free of signing key Date: Tue, 3 Dec 2024 15:47:57 +0100 Message-ID: <20241203144813.020085739@linuxfoundation.org> X-Mailer: git-send-email 2.47.1 In-Reply-To: <20241203144743.428732212@linuxfoundation.org> References: <20241203144743.428732212@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Paulo Alcantara commit 343d7fe6df9e247671440a932b6a73af4fa86d95 upstream. Customers have reported use-after-free in @ses->auth_key.response with SMB2.1 + sign mounts which occurs due to following race: task A task B cifs_mount() dfs_mount_share() get_session() cifs_mount_get_session() cifs_send_recv() cifs_get_smb_ses() compound_send_recv() cifs_setup_session() smb2_setup_request() kfree_sensitive() smb2_calc_signature() crypto_shash_setkey() *UAF* Fix this by ensuring that we have a valid @ses->auth_key.response by checking whether @ses->ses_status is SES_GOOD or SES_EXITING with @ses->ses_lock held. After commit 24a9799aa8ef ("smb: client: fix UAF in smb2_reconnect_server()"), we made sure to call ->logoff() only when @ses was known to be good (e.g. valid ->auth_key.response), so it's safe to access signing key when @ses->ses_status == SES_EXITING. Cc: stable@vger.kernel.org Reported-by: Jay Shin Signed-off-by: Paulo Alcantara (Red Hat) Signed-off-by: Steve French Signed-off-by: Greg Kroah-Hartman --- fs/smb/client/smb2proto.h | 2 - fs/smb/client/smb2transport.c | 56 ++++++++++++++++++++++++++++++------------ 2 files changed, 40 insertions(+), 18 deletions(-) --- a/fs/smb/client/smb2proto.h +++ b/fs/smb/client/smb2proto.h @@ -37,8 +37,6 @@ extern struct mid_q_entry *smb2_setup_re struct smb_rqst *rqst); extern struct mid_q_entry *smb2_setup_async_request( struct TCP_Server_Info *server, struct smb_rqst *rqst); -extern struct cifs_ses *smb2_find_smb_ses(struct TCP_Server_Info *server, - __u64 ses_id); extern struct cifs_tcon *smb2_find_smb_tcon(struct TCP_Server_Info *server, __u64 ses_id, __u32 tid); extern int smb2_calc_signature(struct smb_rqst *rqst, --- a/fs/smb/client/smb2transport.c +++ b/fs/smb/client/smb2transport.c @@ -74,7 +74,7 @@ err: static -int smb2_get_sign_key(__u64 ses_id, struct TCP_Server_Info *server, u8 *key) +int smb3_get_sign_key(__u64 ses_id, struct TCP_Server_Info *server, u8 *key) { struct cifs_chan *chan; struct TCP_Server_Info *pserver; @@ -168,16 +168,41 @@ smb2_find_smb_ses_unlocked(struct TCP_Se return NULL; } -struct cifs_ses * -smb2_find_smb_ses(struct TCP_Server_Info *server, __u64 ses_id) +static int smb2_get_sign_key(struct TCP_Server_Info *server, + __u64 ses_id, u8 *key) { struct cifs_ses *ses; + int rc = -ENOENT; + + if (SERVER_IS_CHAN(server)) + server = server->primary_server; spin_lock(&cifs_tcp_ses_lock); - ses = smb2_find_smb_ses_unlocked(server, ses_id); - spin_unlock(&cifs_tcp_ses_lock); + list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) { + if (ses->Suid != ses_id) + continue; - return ses; + rc = 0; + spin_lock(&ses->ses_lock); + switch (ses->ses_status) { + case SES_EXITING: /* SMB2_LOGOFF */ + case SES_GOOD: + if (likely(ses->auth_key.response)) { + memcpy(key, ses->auth_key.response, + SMB2_NTLMV2_SESSKEY_SIZE); + } else { + rc = -EIO; + } + break; + default: + rc = -EAGAIN; + break; + } + spin_unlock(&ses->ses_lock); + break; + } + spin_unlock(&cifs_tcp_ses_lock); + return rc; } static struct cifs_tcon * @@ -236,14 +261,16 @@ smb2_calc_signature(struct smb_rqst *rqs unsigned char *sigptr = smb2_signature; struct kvec *iov = rqst->rq_iov; struct smb2_hdr *shdr = (struct smb2_hdr *)iov[0].iov_base; - struct cifs_ses *ses; struct shash_desc *shash = NULL; struct smb_rqst drqst; + __u64 sid = le64_to_cpu(shdr->SessionId); + u8 key[SMB2_NTLMV2_SESSKEY_SIZE]; - ses = smb2_find_smb_ses(server, le64_to_cpu(shdr->SessionId)); - if (unlikely(!ses)) { - cifs_server_dbg(FYI, "%s: Could not find session\n", __func__); - return -ENOENT; + rc = smb2_get_sign_key(server, sid, key); + if (unlikely(rc)) { + cifs_server_dbg(FYI, "%s: [sesid=0x%llx] couldn't find signing key: %d\n", + __func__, sid, rc); + return rc; } memset(smb2_signature, 0x0, SMB2_HMACSHA256_SIZE); @@ -260,8 +287,7 @@ smb2_calc_signature(struct smb_rqst *rqs shash = server->secmech.hmacsha256; } - rc = crypto_shash_setkey(shash->tfm, ses->auth_key.response, - SMB2_NTLMV2_SESSKEY_SIZE); + rc = crypto_shash_setkey(shash->tfm, key, sizeof(key)); if (rc) { cifs_server_dbg(VFS, "%s: Could not update with response\n", @@ -303,8 +329,6 @@ smb2_calc_signature(struct smb_rqst *rqs out: if (allocate_crypto) cifs_free_hash(&shash); - if (ses) - cifs_put_smb_ses(ses); return rc; } @@ -570,7 +594,7 @@ smb3_calc_signature(struct smb_rqst *rqs struct smb_rqst drqst; u8 key[SMB3_SIGN_KEY_SIZE]; - rc = smb2_get_sign_key(le64_to_cpu(shdr->SessionId), server, key); + rc = smb3_get_sign_key(le64_to_cpu(shdr->SessionId), server, key); if (unlikely(rc)) { cifs_server_dbg(FYI, "%s: Could not get signing key\n", __func__); return rc;