CVE-2025-21714

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> RDMA/mlx5: Fix implicit ODP use after free<br /> <br /> Prevent double queueing of implicit ODP mr destroy work by using<br /> __xa_cmpxchg() to make sure this is the only time we are destroying this<br /> specific mr.<br /> <br /> Without this change, we could try to invalidate this mr twice, which in<br /> turn could result in queuing a MR work destroy twice, and eventually the<br /> second work could execute after the MR was freed due to the first work,<br /> causing a user after free and trace below.<br /> <br /> refcount_t: underflow; use-after-free.<br /> WARNING: CPU: 2 PID: 12178 at lib/refcount.c:28 refcount_warn_saturate+0x12b/0x130<br /> Modules linked in: bonding ib_ipoib vfio_pci ip_gre geneve nf_tables ip6_gre gre ip6_tunnel tunnel6 ipip tunnel4 ib_umad rdma_ucm mlx5_vfio_pci vfio_pci_core vfio_iommu_type1 mlx5_ib vfio ib_uverbs mlx5_core iptable_raw openvswitch nsh rpcrdma ib_iser libiscsi scsi_transport_iscsi rdma_cm iw_cm ib_cm ib_core xt_conntrack xt_MASQUERADE nf_conntrack_netlink nfnetlink xt_addrtype iptable_nat nf_nat br_netfilter rpcsec_gss_krb5 auth_rpcgss oid_registry overlay zram zsmalloc fuse [last unloaded: ib_uverbs]<br /> CPU: 2 PID: 12178 Comm: kworker/u20:5 Not tainted 6.5.0-rc1_net_next_mlx5_58c644e #1<br /> Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014<br /> Workqueue: events_unbound free_implicit_child_mr_work [mlx5_ib]<br /> RIP: 0010:refcount_warn_saturate+0x12b/0x130<br /> Code: 48 c7 c7 38 95 2a 82 c6 05 bc c6 fe 00 01 e8 0c 66 aa ff 0f 0b 5b c3 48 c7 c7 e0 94 2a 82 c6 05 a7 c6 fe 00 01 e8 f5 65 aa ff 0b 5b c3 90 8b 07 3d 00 00 00 c0 74 12 83 f8 01 74 13 8d 50 ff<br /> RSP: 0018:ffff8881008e3e40 EFLAGS: 00010286<br /> RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000027<br /> RDX: ffff88852c91b5c8 RSI: 0000000000000001 RDI: ffff88852c91b5c0<br /> RBP: ffff8881dacd4e00 R08: 00000000ffffffff R09: 0000000000000019<br /> R10: 000000000000072e R11: 0000000063666572 R12: ffff88812bfd9e00<br /> R13: ffff8881c792d200 R14: ffff88810011c005 R15: ffff8881002099c0<br /> FS: 0000000000000000(0000) GS:ffff88852c900000(0000) knlGS:0000000000000000<br /> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033<br /> CR2: 00007f5694b5e000 CR3: 00000001153f6003 CR4: 0000000000370ea0<br /> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000<br /> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400<br /> Call Trace:<br /> <br /> ? refcount_warn_saturate+0x12b/0x130<br /> free_implicit_child_mr_work+0x180/0x1b0 [mlx5_ib]<br /> process_one_work+0x1cc/0x3c0<br /> worker_thread+0x218/0x3c0<br /> kthread+0xc6/0xf0<br /> ret_from_fork+0x1f/0x30<br />