CVE-2025-21888

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> RDMA/mlx5: Fix a WARN during dereg_mr for DM type<br /> <br /> Memory regions (MR) of type DM (device memory) do not have an associated<br /> umem.<br /> <br /> In the __mlx5_ib_dereg_mr() -&gt; mlx5_free_priv_descs() flow, the code<br /> incorrectly takes the wrong branch, attempting to call<br /> dma_unmap_single() on a DMA address that is not mapped.<br /> <br /> This results in a WARN [1], as shown below.<br /> <br /> The issue is resolved by properly accounting for the DM type and<br /> ensuring the correct branch is selected in mlx5_free_priv_descs().<br /> <br /> [1]<br /> WARNING: CPU: 12 PID: 1346 at drivers/iommu/dma-iommu.c:1230 iommu_dma_unmap_page+0x79/0x90<br /> Modules linked in: ip6table_mangle ip6table_nat ip6table_filter ip6_tables iptable_mangle xt_conntrack xt_MASQUERADE nf_conntrack_netlink nfnetlink xt_addrtype iptable_nat nf_nat br_netfilter rpcsec_gss_krb5 auth_rpcgss oid_registry ovelay rpcrdma rdma_ucm ib_iser libiscsi scsi_transport_iscsi ib_umad rdma_cm ib_ipoib iw_cm ib_cm mlx5_ib ib_uverbs ib_core fuse mlx5_core<br /> CPU: 12 UID: 0 PID: 1346 Comm: ibv_rc_pingpong Not tainted 6.12.0-rc7+ #1631<br /> Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014<br /> RIP: 0010:iommu_dma_unmap_page+0x79/0x90<br /> Code: 2b 49 3b 29 72 26 49 3b 69 08 73 20 4d 89 f0 44 89 e9 4c 89 e2 48 89 ee 48 89 df 5b 5d 41 5c 41 5d 41 5e 41 5f e9 07 b8 88 ff 0b 5b 5d 41 5c 41 5d 41 5e 41 5f c3 cc cc cc cc 66 0f 1f 44 00<br /> RSP: 0018:ffffc90001913a10 EFLAGS: 00010246<br /> RAX: 0000000000000000 RBX: ffff88810194b0a8 RCX: 0000000000000000<br /> RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001<br /> RBP: ffff88810194b0a8 R08: 0000000000000000 R09: 0000000000000000<br /> R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000<br /> R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000000<br /> FS: 00007f537abdd740(0000) GS:ffff88885fb00000(0000) knlGS:0000000000000000<br /> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033<br /> CR2: 00007f537aeb8000 CR3: 000000010c248001 CR4: 0000000000372eb0<br /> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000<br /> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400<br /> Call Trace:<br /> <br /> ? __warn+0x84/0x190<br /> ? iommu_dma_unmap_page+0x79/0x90<br /> ? report_bug+0xf8/0x1c0<br /> ? handle_bug+0x55/0x90<br /> ? exc_invalid_op+0x13/0x60<br /> ? asm_exc_invalid_op+0x16/0x20<br /> ? iommu_dma_unmap_page+0x79/0x90<br /> dma_unmap_page_attrs+0xe6/0x290<br /> mlx5_free_priv_descs+0xb0/0xe0 [mlx5_ib]<br /> __mlx5_ib_dereg_mr+0x37e/0x520 [mlx5_ib]<br /> ? _raw_spin_unlock_irq+0x24/0x40<br /> ? wait_for_completion+0xfe/0x130<br /> ? rdma_restrack_put+0x63/0xe0 [ib_core]<br /> ib_dereg_mr_user+0x5f/0x120 [ib_core]<br /> ? lock_release+0xc6/0x280<br /> destroy_hw_idr_uobject+0x1d/0x60 [ib_uverbs]<br /> uverbs_destroy_uobject+0x58/0x1d0 [ib_uverbs]<br /> uobj_destroy+0x3f/0x70 [ib_uverbs]<br /> ib_uverbs_cmd_verbs+0x3e4/0xbb0 [ib_uverbs]<br /> ? __pfx_uverbs_destroy_def_handler+0x10/0x10 [ib_uverbs]<br /> ? lock_acquire+0xc1/0x2f0<br /> ? ib_uverbs_ioctl+0xcb/0x170 [ib_uverbs]<br /> ? ib_uverbs_ioctl+0x116/0x170 [ib_uverbs]<br /> ? lock_release+0xc6/0x280<br /> ib_uverbs_ioctl+0xe7/0x170 [ib_uverbs]<br /> ? ib_uverbs_ioctl+0xcb/0x170 [ib_uverbs]<br /> __x64_sys_ioctl+0x1b0/0xa70<br /> do_syscall_64+0x6b/0x140<br /> entry_SYSCALL_64_after_hwframe+0x76/0x7e<br /> RIP: 0033:0x7f537adaf17b<br /> Code: 0f 1e fa 48 8b 05 1d ad 0c 00 64 c7 00 26 00 00 00 48 c7 c0 ff ff ff ff c3 66 0f 1f 44 00 00 f3 0f 1e fa b8 10 00 00 00 0f 05 3d 01 f0 ff ff 73 01 c3 48 8b 0d ed ac 0c 00 f7 d8 64 89 01 48<br /> RSP: 002b:00007ffff218f0b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010<br /> RAX: ffffffffffffffda RBX: 00007ffff218f1d8 RCX: 00007f537adaf17b<br /> RDX: 00007ffff218f1c0 RSI: 00000000c0181b01 RDI: 0000000000000003<br /> RBP: 00007ffff218f1a0 R08: 00007f537aa8d010 R09: 0000561ee2e4f270<br /> R10: 00007f537aace3a8 R11: 0000000000000246 R12: 00007ffff218f190<br /> R13: 000000000000001c R14: 0000561ee2e4d7c0 R15: 00007ffff218f450<br />