CVE-2026-64383

CRITICAL9.8

Published 2026-07-25 · Updated 2026-07-27 · Source 416baaa9-dc9f-4396-8d5f-8c081fb06d67

Description

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix double-free in SMB2_flush() replay SMB2_flush() keeps its response buffer bookkeeping across replay attempts. If a replayable flush response is received and the retry then fails before cifs_send_recv() stores a replacement response, flush_exit will free the stale response pointer a second time. Reinitialize resp_buftype and rsp_iov at the top of the replay loop so cleanup only acts on response state produced by the current attempt. This fixes a double-free without changing replay handling for successful requests.

CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

References

View on NVD

Related CVEs

Same severity, most recent

CVE-2026-64530
In the Linux kernel, the following vulnerability has been resolved: net/sched: cls_api: Handle TC_ACT_CONSUMED in tcf_qevent_handle tcf_classify() can return TC_ACT_CONSUMED while the skb is held by the defragmentation engine (e.g. act_ct on out-of-order fragments). When that happens the skb is no longer owned by the caller and must not be touched again. tcf_qevent_handle() did not handle TC_ACT_CONSUMED: it fell through the switch and returned the skb to the caller as if classification had passed. The only qdisc that wires up qevents today is RED, via three call sites (qe_mark on RED_PROB_MARK/HARD_MARK, qe_early_drop on congestion_drop) red_enqueue() was continuing to operate on an skb it no longer owns in this case -- enqueueing it, dropping it, or updating statistics. Resulting in a UAF. tc qdisc add dev eth0 root handle 1: red ... qevent early_drop block 10 tc filter add block 10 ... action ct (with ct defrag enabled and traffic that produces out-of-order fragments, e.g. a fragmented UDP stream) Handle TC_ACT_CONSUMED in tcf_qevent_handle() the same way the ingress and egress fast paths do: treat it as stolen and return NULL without touching the skb. Unlike the TC_ACT_STOLEN case, the skb must not be dropped/freed here, as it is no longer owned by us.
2026-07-26 · score 9.8
CVE-2026-66012
SiYuan before v3.7.2 contains a missing authorization vulnerability in the POST /mcp kernel endpoint, which is gated only by a general auth check (model.CheckAuth) with no admin-role or read-only enforcement. This exposes 31 MCP tools, including a file tool with list/read/write/delete/rename/copy actions across the entire workspace. When the Publish server is enabled in anonymous mode (Conf.Publish.Enable=true and Conf.Publish.Auth.Enable=false), the Publish reverse proxy attaches an anonymous RoleReader JWT to proxied requests, allowing a remote unauthenticated attacker to reach /mcp. The attacker can read conf/conf.json to extract accessAuthCode, api.token, and cookieKey in plaintext, write arbitrary files in the workspace, and plant a plugin into data/plugins/ that executes with nodeIntegration:true and no contextIsolation on the next desktop launch, leading to administrator takeover.
2026-07-25 · score 10.0
CVE-2026-64523
In the Linux kernel, the following vulnerability has been resolved: net/handshake: Take a long-lived file reference at submit handshake_nl_accept_doit() needs the file pointer backing req->hr_sk->sk_socket to survive the window between handshake_req_next() and the subsequent FD_PREPARE() and get_file(). The submit-side sock_hold() does not provide that. sk_refcnt keeps struct sock alive, but struct socket is owned by sock->file: when the consumer fputs the last file reference, sock_release() tears the socket down regardless of any sock_hold. Add an hr_file pointer to struct handshake_req and acquire an explicit reference on sock->file during handshake_req_submit(). handshake_complete() and handshake_req_cancel() release the reference on the completion-bit-winning path. The submit error path must also release the file reference, but after rhashtable insertion a concurrent handshake_req_cancel() can discover the request and race the error path. Gate the error-path cleanup -- sk_destruct restoration, fput, and request destruction -- with test_and_set_bit(HANDSHAKE_F_REQ_COMPLETED), the same serialization handshake_complete() and handshake_req_cancel() already use. When cancel has already claimed ownership, the submit error path returns without touching the request; socket teardown handles final destruction. The accept-side dereferences are not yet retargeted; that change comes in the next patch.
2026-07-25 · score 9.8
CVE-2026-64459
In the Linux kernel, the following vulnerability has been resolved: tcp: restore RCU grace period in tcp_ao_destroy_sock Commit 51e547e8c89c ("tcp: Free TCP-AO/TCP-MD5 info/keys without RCU") removed the call_rcu() callback from tcp_ao_destroy_sock(), arguing that "the destruction of info/keys is delayed until the socket destructor" and therefore "no one can discover it anymore". That argument does not hold for the call site in tcp_connect() (net/ipv4/tcp_output.c:4327-4332). At that point the socket is in TCP_SYN_SENT, has already been inserted into the inet ehash by inet_hash_connect() in tcp_v4_connect(), and is therefore very much discoverable: any softirq running tcp_v4_rcv() on another CPU can take the socket out of the ehash, walk into tcp_inbound_hash(), and load tp->ao_info via implicit RCU before bh_lock_sock_nested() is taken on the destroying CPU. The reader path then enters __tcp_ao_do_lookup() (net/ipv4/tcp_ao.c:208) which re-loads tp->ao_info via rcu_dereference_check(); the re-load can still observe the (about-to-be-freed) pointer because there is no synchronize_rcu() between rcu_assign_pointer(tp->ao_info, NULL) and tcp_ao_info_free() in tcp_ao_destroy_sock(). The captured pointer is then walked at line 223: hlist_for_each_entry_rcu(key, &ao->head, node, ...) The writer's synchronous kfree() is free to complete between the line 218 re-fetch and the line 223 hlist iteration. The slab is reused (or simply LIST_POISON1-stamped if not yet reused) and the iteration walks attacker-controlled or poison memory in softirq context. Reproducer (no debug shim, stock x86_64 v7.1-rc2 SMP+KASAN, QEMU+KVM): an unprivileged uid=1000 process inside CLONE_NEWUSER|CLONE_NEWNET installs TCP_MD5SIG + TCP_AO_ADD_KEY on a TCP socket, sprays forged TCP-AO segments toward its eventual 4-tuple via raw sockets, then calls connect(). The md5-wins reconciliation in tcp_connect() fires tcp_ao_destroy_sock(); the softirq backlog reader on the loopback NAPI path crashes on the freed ao->head.first walk: Oops: general protection fault, probably for non-canonical address 0xfbd59c000000002f KASAN: maybe wild-memory-access in range [0xdead000000000178-0xdead00000000017f] CPU: 0 UID: 1000 PID: 100 Comm: repro_userns RIP: 0010:__tcp_ao_do_lookup+0x107/0x1c0 Call Trace: <IRQ> __tcp_ao_do_lookup+0x107/0x1c0 tcp_ao_inbound_lookup.constprop.0+0x12a/0x200 tcp_inbound_ao_hash+0x5ea/0x1520 tcp_inbound_hash+0x7ce/0x1240 tcp_v4_rcv+0x1e7a/0x3e10 ... Restore the RCU grace period: re-add struct rcu_head to tcp_ao_info and replace the synchronous tcp_ao_info_free() with a call_rcu() callback. Readers that captured tp->ao_info before rcu_assign_pointer NULLed it now see the object remain valid until rcu_read_unlock(). With the patch applied the reproducer runs cleanly for 2000 iterations on the same kernel build.
2026-07-25 · score 9.8
CVE-2026-64450
In the Linux kernel, the following vulnerability has been resolved: tipc: fix out-of-bounds read in broadcast Gap ACK blocks A broadcast PROTOCOL/STATE_MSG can carry a Gap ACK blocks record in its data area. tipc_get_gap_ack_blks() only verifies that the record's len field is self-consistent with its ugack_cnt/bgack_cnt counts (sz == struct_size(p, gacks, ugack_cnt + bgack_cnt)); it does not check that the record actually fits in the message data area, msg_data_sz(). The unicast caller tipc_link_proto_rcv() bounds it ("if (glen > dlen) break;"), but the broadcast caller tipc_bcast_sync_rcv() discards the returned size, so tipc_link_advance_transmq() copies the record off the receive skb with an attacker-controlled count: this_ga = kmemdup(ga, struct_size(ga, gacks, ga->bgack_cnt), GFP_ATOMIC); A TIPC neighbour that negotiated TIPC_GAP_ACK_BLOCK triggers it with one ordinary broadcast STATE_MSG (msg_bc_ack_invalid() clear), sized so its data area is short, carrying a Gap ACK record with len = 0x400, bgack_cnt = 0xff and ugack_cnt = 0. len then equals struct_size(p, gacks, 255), so the consistency check passes and ga is non-NULL; kmemdup() reads struct_size(ga, gacks, 255) = 1024 bytes out of the much smaller skb: BUG: KASAN: slab-out-of-bounds in kmemdup_noprof+0x48/0x60 Read of size 1024 at addr ffff0000c7030d38 by task poc864/69 Call trace: kmemdup_noprof+0x48/0x60 tipc_link_advance_transmq+0x86c/0xb80 tipc_link_bc_ack_rcv+0x19c/0x1e0 tipc_bcast_sync_rcv+0x1c4/0x2c4 tipc_rcv+0x85c/0x1340 tipc_l2_rcv_msg+0xac/0x104 The buggy address belongs to the object at ffff0000c7030d00 which belongs to the cache skbuff_small_head of size 704 The buggy address is located 56 bytes inside of allocated 704-byte region [ffff0000c7030d00, ffff0000c7030fc0) The copied-out bytes are subsequently consumed as gap/ack values, but the read is already out of bounds at the kmemdup() regardless of how they are used. The unicast STATE path drops such a message: "if (glen > dlen) break;" skips the rest of STATE_MSG handling and the skb is freed. Make the broadcast path drop it too. tipc_bcast_sync_rcv() now bounds the record against msg_data_sz() and, when it does not fit, reports it back through tipc_node_bc_sync_rcv() to tipc_rcv() so the skb is discarded rather than processed. ga is not cleared on this path: ga == NULL already means "legacy peer without Selective ACK", a distinct legitimate state.
2026-07-25 · score 9.1