CVE-2025-21714: RDMA/mlx5: Fix implicit ODP use after free
Description
In the Linux kernel, the following vulnerability has been resolved:
RDMA/mlx5: Fix implicit ODP use after free
Prevent double queueing of implicit ODP mr destroy work by using
__xa_cmpxchg() to make sure this is the only time we are destroying this
specific mr.
Without this change, we could try to invalidate this mr twice, which in
turn could result in queuing a MR work destroy twice, and eventually the
second work could execute after the MR was freed due to the first work,
causing a user after free and trace below.
refcount_t: underflow; use-after-free.
WARNING: CPU: 2 PID: 12178 at lib/refcount.c:28 refcount_warn_saturate+0x12b/0x130
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]
CPU: 2 PID: 12178 Comm: kworker/u20:5 Not tainted 6.5.0-rc1_net_next_mlx5_58c644e #1
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
Workqueue: events_unbound free_implicit_child_mr_work [mlx5_ib]
RIP: 0010:refcount_warn_saturate+0x12b/0x130
Code: 48 c7...
Classification
CVE ID: CVE-2025-21714
Affected Products
Vendor: Linux, Linux
Product: Linux, Linux
Exploit Prediction Scoring System (EPSS)
EPSS Score: 0.02% (probability of being exploited)
EPSS Percentile: 1.7% (scored less or equal to compared to others)
EPSS Date: 2025-03-27 (when was this score calculated)
References
https://nvd.nist.gov/vuln/detail/CVE-2025-21714https://git.kernel.org/stable/c/7cc8f681f6d4ae4478ae0f60485fc768f2b450da
https://git.kernel.org/stable/c/edfb65dbb9ffd3102f3ff4dd21316158e56f1976
https://git.kernel.org/stable/c/d3d930411ce390e532470194296658a960887773