Message-ID: <2025032714-CVE-2025-21888-0f83@gregkh>
Date: Thu, 27 Mar 2025 15:58:22 +0100
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: linux-cve-announce@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Subject: CVE-2025-21888: RDMA/mlx5: Fix a WARN during dereg_mr for DM type

Description
===========

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

RDMA/mlx5: Fix a WARN during dereg_mr for DM type

Memory regions (MR) of type DM (device memory) do not have an associated
umem.

In the __mlx5_ib_dereg_mr() -> mlx5_free_priv_descs() flow, the code
incorrectly takes the wrong branch, attempting to call
dma_unmap_single() on a DMA address that is not mapped.

This results in a WARN [1], as shown below.

The issue is resolved by properly accounting for the DM type and
ensuring the correct branch is selected in mlx5_free_priv_descs().

[1]
WARNING: CPU: 12 PID: 1346 at drivers/iommu/dma-iommu.c:1230 iommu_dma_unmap_page+0x79/0x90
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
CPU: 12 UID: 0 PID: 1346 Comm: ibv_rc_pingpong Not tainted 6.12.0-rc7+ #1631
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
RIP: 0010:iommu_dma_unmap_page+0x79/0x90
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 <0f> 0b 5b 5d 41 5c 41 5d 41 5e 41 5f c3 cc cc cc cc 66 0f 1f 44 00
RSP: 0018:ffffc90001913a10 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff88810194b0a8 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001
RBP: ffff88810194b0a8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000000
FS:  00007f537abdd740(0000) GS:ffff88885fb00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f537aeb8000 CR3: 000000010c248001 CR4: 0000000000372eb0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
? __warn+0x84/0x190
? iommu_dma_unmap_page+0x79/0x90
? report_bug+0xf8/0x1c0
? handle_bug+0x55/0x90
? exc_invalid_op+0x13/0x60
? asm_exc_invalid_op+0x16/0x20
? iommu_dma_unmap_page+0x79/0x90
dma_unmap_page_attrs+0xe6/0x290
mlx5_free_priv_descs+0xb0/0xe0 [mlx5_ib]
__mlx5_ib_dereg_mr+0x37e/0x520 [mlx5_ib]
? _raw_spin_unlock_irq+0x24/0x40
? wait_for_completion+0xfe/0x130
? rdma_restrack_put+0x63/0xe0 [ib_core]
ib_dereg_mr_user+0x5f/0x120 [ib_core]
? lock_release+0xc6/0x280
destroy_hw_idr_uobject+0x1d/0x60 [ib_uverbs]
uverbs_destroy_uobject+0x58/0x1d0 [ib_uverbs]
uobj_destroy+0x3f/0x70 [ib_uverbs]
ib_uverbs_cmd_verbs+0x3e4/0xbb0 [ib_uverbs]
? __pfx_uverbs_destroy_def_handler+0x10/0x10 [ib_uverbs]
? lock_acquire+0xc1/0x2f0
? ib_uverbs_ioctl+0xcb/0x170 [ib_uverbs]
? ib_uverbs_ioctl+0x116/0x170 [ib_uverbs]
? lock_release+0xc6/0x280
ib_uverbs_ioctl+0xe7/0x170 [ib_uverbs]
? ib_uverbs_ioctl+0xcb/0x170 [ib_uverbs]
__x64_sys_ioctl+0x1b0/0xa70
do_syscall_64+0x6b/0x140
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f537adaf17b
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 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d ed ac 0c 00 f7 d8 64 89 01 48
RSP: 002b:00007ffff218f0b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007ffff218f1d8 RCX: 00007f537adaf17b
RDX: 00007ffff218f1c0 RSI: 00000000c0181b01 RDI: 0000000000000003
RBP: 00007ffff218f1a0 R08: 00007f537aa8d010 R09: 0000561ee2e4f270
R10: 00007f537aace3a8 R11: 0000000000000246 R12: 00007ffff218f190
R13: 000000000000001c R14: 0000561ee2e4d7c0 R15: 00007ffff218f450
</TASK>

The Linux kernel CVE team has assigned CVE-2025-21888 to this issue.


Affected and fixed versions
===========================

	Issue introduced in 5.13 with commit f18ec422311767738ef4033b61e91cae07163b22 and fixed in 6.12.18 with commit 0bd34bdd468e93a779c403de3cf7d43ee633b3e0
	Issue introduced in 5.13 with commit f18ec422311767738ef4033b61e91cae07163b22 and fixed in 6.13.6 with commit f1298cad47ae29828c5c5be77e733ccfcaef6a7f
	Issue introduced in 5.13 with commit f18ec422311767738ef4033b61e91cae07163b22 and fixed in 6.14 with commit abc7b3f1f056d69a8f11d6dceecc0c9549ace770

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2025-21888
will be updated if fixes are backported, please check that for the most
up to date information about this issue.


Affected files
==============

The file(s) affected by this issue are:
	drivers/infiniband/hw/mlx5/mr.c


Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/0bd34bdd468e93a779c403de3cf7d43ee633b3e0
	https://git.kernel.org/stable/c/f1298cad47ae29828c5c5be77e733ccfcaef6a7f
	https://git.kernel.org/stable/c/abc7b3f1f056d69a8f11d6dceecc0c9549ace770

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