CVE-2025-38035

In the Linux kernel, the following vulnerability has been resolved:

nvmet-tcp: don't restore null sk_state_change

queue->state_change is set as part of nvmet_tcp_set_queue_sock(), but if the TCP connection isn't established when nvmet_tcp_set_queue_sock() is called then queue->state_change isn't set and sock->sk->sk_state_change isn't replaced.

As such we don't need to restore sock->sk->sk_state_change if queue->state_change is NULL.

This avoids NULL pointer dereferences such as this:

[ 286.462026][ C0] BUG: kernel NULL pointer dereference, address: 0000000000000000 [ 286.462814][ C0] #PF: supervisor instruction fetch in kernel mode [ 286.463796][ C0] #PF: error_code(0x0010) - not-present page [ 286.464392][ C0] PGD 8000000140620067 P4D 8000000140620067 PUD 114201067 PMD 0 [ 286.465086][ C0] Oops: Oops: 0010 [#1] SMP KASAN PTI [ 286.465559][ C0] CPU: 0 UID: 0 PID: 1628 Comm: nvme Not tainted 6.15.0-rc2+ #11 PREEMPT(voluntary) [ 286.466393][ C0] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-3.fc41 04/01/2014 [ 286.467147][ C0] RIP: 0010:0x0 [ 286.467420][ C0] Code: Unable to access opcode bytes at 0xffffffffffffffd6. [ 286.467977][ C0] RSP: 0018:ffff8883ae008580 EFLAGS: 00010246 [ 286.468425][ C0] RAX: 0000000000000000 RBX: ffff88813fd34100 RCX: ffffffffa386cc43 [ 286.469019][ C0] RDX: 1ffff11027fa68b6 RSI: 0000000000000008 RDI: ffff88813fd34100 [ 286.469545][ C0] RBP: ffff88813fd34160 R08: 0000000000000000 R09: ffffed1027fa682c [ 286.470072][ C0] R10: ffff88813fd34167 R11: 0000000000000000 R12: ffff88813fd344c3 [ 286.470585][ C0] R13: ffff88813fd34112 R14: ffff88813fd34aec R15: ffff888132cdd268 [ 286.471070][ C0] FS: 00007fe3c04c7d80(0000) GS:ffff88840743f000(0000) knlGS:0000000000000000 [ 286.471644][ C0] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 286.472543][ C0] CR2: ffffffffffffffd6 CR3: 000000012daca000 CR4: 00000000000006f0 [ 286.473500][ C0] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 286.474467][ C0] DR3: 0000000000000000 DR6: 00000000ffff07f0 DR7: 0000000000000400 [ 286.475453][ C0] Call Trace: [ 286.476102][ C0] <IRQ> [ 286.476719][ C0] tcp_fin+0x2bb/0x440 [ 286.477429][ C0] tcp_data_queue+0x190f/0x4e60 [ 286.478174][ C0] ? __build_skb_around+0x234/0x330 [ 286.478940][ C0] ? rcu_is_watching+0x11/0xb0 [ 286.479659][ C0] ? __pfx_tcp_data_queue+0x10/0x10 [ 286.480431][ C0] ? tcp_try_undo_loss+0x640/0x6c0 [ 286.481196][ C0] ? seqcount_lockdep_reader_access.constprop.0+0x82/0x90 [ 286.482046][ C0] ? kvm_clock_get_cycles+0x14/0x30 [ 286.482769][ C0] ? ktime_get+0x66/0x150 [ 286.483433][ C0] ? rcu_is_watching+0x11/0xb0 [ 286.484146][ C0] tcp_rcv_established+0x6e4/0x2050 [ 286.484857][ C0] ? rcu_is_watching+0x11/0xb0 [ 286.485523][ C0] ? ipv4_dst_check+0x160/0x2b0 [ 286.486203][ C0] ? __pfx_tcp_rcv_established+0x10/0x10 [ 286.486917][ C0] ? lock_release+0x217/0x2c0 [ 286.487595][ C0] tcp_v4_do_rcv+0x4d6/0x9b0 [ 286.488279][ C0] tcp_v4_rcv+0x2af8/0x3e30 [ 286.488904][ C0] ? raw_local_deliver+0x51b/0xad0 [ 286.489551][ C0] ? rcu_is_watching+0x11/0xb0 [ 286.490198][ C0] ? __pfx_tcp_v4_rcv+0x10/0x10 [ 286.490813][ C0] ? __pfx_raw_local_deliver+0x10/0x10 [ 286.491487][ C0] ? __pfx_nf_confirm+0x10/0x10 [nf_conntrack] [ 286.492275][ C0] ? rcu_is_watching+0x11/0xb0 [ 286.492900][ C0] ip_protocol_deliver_rcu+0x8f/0x370 [ 286.493579][ C0] ip_local_deliver_finish+0x297/0x420 [ 286.494268][ C0] ip_local_deliver+0x168/0x430 [ 286.494867][ C0] ? __pfx_ip_local_deliver+0x10/0x10 [ 286.495498][ C0] ? __pfx_ip_local_deliver_finish+0x10/0x10 [ 286.496204][ C0] ? ip_rcv_finish_core+0x19a/0x1f20 [ 286.496806][ C0] ? lock_release+0x217/0x2c0 [ 286.497414][ C0] ip_rcv+0x455/0x6e0 [ 286.497945][ C0] ? __pfx_ip_rcv+0x10/0x10 [ ---truncated---

This vulnerability is rated as Moderate impact for Red Hat Enterprise Linux because exploitation is confined to a denial of service via a kernel crash, with no possibility of privilege escalation or data compromise. By default, Red Hat systems do not load or expose the NVMe over Fabrics TCP target module unless the host is explicitly configured as a network storage target. The crash can only occur during unestablished or aborted socket handshakes, restricting exposure to environments actively offering NVMe over TCP storage.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.