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CVE-2025-68379
RDMA/rxe: Fix null deref on srq->rq.queue after resize failure
Published 2025-12-24 (10 months ago) by the Linux kernel CNA. Subsystem drivers/infiniband. Debian urgency: not yet assigned.
What to do, per Debian release
Debian's own status for CVE-2025-68379 in every release this site tracks, and what each one means in practice. Every status below is the one the Debian Security Team publishes for this CVE. source
| Release | Status | Version | What this means |
|---|---|---|---|
| Debian 12bookworm | vulnerable | 6.1.190-1 | No fix published anywhere yet, neither in Debian nor upstream for the series bookworm tracks. Watch the Debian tracker page for this CVE. Advisories for bookworm have historically landed a median of 23 days after publication. |
| Debian 13trixie | fixed | 6.12.63-1 | Update the kernel and reboot. Fixed in 6.12.63-1. A running kernel keeps the old code until the machine restarts. |
| Debian 14forky | fixed | 6.17.13-1 | Update the kernel and reboot. Fixed in 6.17.13-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 6.17.13-1 | Update the kernel and reboot. Fixed in 6.17.13-1. A running kernel keeps the old code until the machine restarts. |
The vulnerability
What the bug is
A NULL pointer dereference can occur in rxe_srq_chk_attr() when ibv_modify_srq() is invoked twice in succession under certain error conditions. The first call may fail in rxe_queue_resize(), which leads rxe_srq_from_attr() to set srq->rq.queue = NULL. The second call then triggers a crash (null deref) when accessing srq->rq.queue->buf->index_mask. Call Trace: <TASK> rxe_modify_srq+0x170/0x480 [rdma_rxe] ? __pfx_rxe_modify_srq+0x10/0x10 [rdma_rxe] ? uverbs_try_lock_object+0x4f/0xa0 [ib_uverbs] ? rdma_lookup_get_uobject+0x1f0/0x380 [ib_uverbs] ib_uverbs_modify_srq+0x204/0x290 [ib_uverbs] ? __pfx_ib_uverbs_modify_srq+0x10/0x10 [ib_uverbs] ? tryinc_node_nr_active+0xe6/0x150 ? uverbs_fill_udata+0xed/0x4f0 [ib_uverbs] ib_uverbs_handler_UVERBS_METHOD_INVOKE_WRITE+0x2c0/0x470 [ib_uverbs] ? __pfx_ib_uverbs_handler_UVERBS_METHOD_INVOKE_WRITE+0x10/0x10 [ib_uverbs] ? uverbs_fill_udata+0xed/0x4f0 [ib_uverbs] ib_uverbs_run_method+0x55a/0x6e0 [ib_uverbs] ? __pfx_ib_uverbs_handler_UVERBS_METHOD_INVOKE_WRITE+0x10/0x10 [ib_uverbs] ib_uverbs_cmd_verbs+0x54d/0x800 [ib_uverbs] ? __pfx_ib_uverbs_cmd_verbs+0x10/0x10 [ib_uverbs] ? __pfx___raw_spin_lock_irqsave+0x10/0x10 ? __pfx_do_vfs_ioctl+0x10/0x10 ? ioctl_has_perm.constprop.0.isra.0+0x2c7/0x4c0 ? __pfx_ioctl_has_perm.constprop.0.isra.0+0x10/0x10 ib_uverbs_ioctl+0x13e/0x220 [ib_uverbs] ? __pfx_ib_uverbs_ioctl+0x10/0x10 [ib_uverbs] __x64_sys_ioctl+0x138/0x1c0 do_syscall_64+0x82/0x250 ? fdget_pos+0x58/0x4c0 ? ksys_write+0xf3/0x1c0 ? __pfx_ksys_write+0x10/0x10 ? do_syscall_64+0xc8/0x250 ? __pfx_vm_mmap_pgoff+0x10/0x10 ? fget+0x173/0x230 ? fput+0x2a/0x80 ? ksys_mmap_pgoff+0x224/0x4c0 ? do_syscall_64+0xc8/0x250 ? do_user_addr_fault+0x37b/0xfe0 ? clear_bhb_loop+0x50/0xa0 ? clear_bhb_loop+0x50/0xa0 ? clear_bhb_loop+0x50/0xa0 entry_SYSCALL_64_after_hwframe+0x76/0x7e
Where it lives
The fix touches these files. If the subsystem is one you do not use, the practical exposure is lower, though the package is still the vulnerable one.
drivers/infiniband/sw/rxe/rxe_srq.c
- What this is
- SOFT-ROCE DRIVER (rxe)MAINTAINERS section matched on drivers/infiniband/sw/rxe/ · linux-rdma@vger.kernel.org · Supported
- Kernel module
- rdma_rxe
Check it on the machine
grep -wE 'CONFIG_INFINIBAND|CONFIG_RDMA_RXE' /boot/config-$(uname -r)Reads the booted kernel's own configuration, on the machine and nowhere else. =y is built in, =m is a module, and an is not set line means the code is not there.
lsmod | grep -w rdma_rxePrints a line if that module is loaded right now, and nothing if it is not. One that is not loaded can still be loaded later by anything that needs it.
Show whether Debian builds this, per release
Debian builds this, but not on every flavour. At least one release below builds the code on some of its kernel flavours and not on others, so the answer depends on the architecture and flavour installed.
- bookwormMnot built on amd64/cloud-amd64, arm64/cloud-arm64, armhf/armmp, armhf/armmp-lpae, armhf/rt/armmp, i386/686, i386/686-pae, i386/rt/686-pae
- trixieMnot built on amd64/cloud-amd64, arm64/cloud-arm64, armel/rpi, armhf/armmp, armhf/armmp-lpae, armhf/rt/armmp
- forky, sidMnot built on amd64/cloud-amd64, arm64/cloud-arm64, armhf/armmp, armhf/armmp-lpae
- M
- a module where it is built at all; some flavours do not build it
- Build switches
- CONFIG_INFINIBAND, CONFIG_RDMA_RXE
- Reads as
- all on means the file is compiled; any one off means it is not.
From the configuration Debian publishes for every kernel flavour it builds. It covers only the architectures Debian ships a linux-config package for, and nothing about a kernel you built yourself. Debian's own status above stays authoritative about the source package.MAINTAINERS kbuild Makefiles Debian linux-config packages
Signals
- Published
- 2025-12-24 (10 months ago)source
- CVSS
- 7.8 high
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Hsource recompute it - Attack vector
- local (AV:L)source
- EPSS
- 0.14%, higher than 3.3% of all CVEssource
- CISA KEV
- not listedthe KEV catalogue
- Debian urgency
- not yet assignedsource
- Subsystem
- drivers/infiniband
Upstream fixes
The versions the CNA records as introducing and fixing this, and the commit for each. source
| Introduced | Fixed in | Commit |
|---|---|---|
| 4.8 | 6.6.120 | 58aca869babd |
| 4.8 | 6.12.63 | b8f6eeb87a76 |
| 4.8 | 6.17.13 | 5dbeb421e137 |
| 4.8 | 6.18.2 | bc4c14a3863c |
| 4.8 | 6.19 | 503a5e4690ae |
Why the CNA scored it this way
Quoted from the kernel CNA's own scoring file, word for word. A highlighted metric carries the most severe value CVSS v3.1 defines for it, which is what pushes the score up. source
- AV:LAttack vector, local
- The required corruption is initiated through a local RDMA uverbs ioctl or write that modifies an attacker-owned RXE SRQ. Network traffic can exercise the damaged queue concurrently, but a remote peer cannot perform the required resize.
- AC:LAttack complexity, low
- The attacker can deliberately fail resizing using an invalid mmap-info destination or controlled queue occupancy, then issue another modification. Any use-after-free race involves attacker-controlled concurrent uverbs calls or traffic.
- PR:LPrivileges required, low
- An unprivileged user can open the mode-0666 uverbs device, create a context, PD, and SRQ, and invoke modify without capability checks. Object lookup requires ownership of the SRQ but no administrative privilege.
- UI:NUser interaction, none
- Exploitation requires no action by another user; the attacker creates and modifies the affected SRQ directly.
- S:UScope, unchanged
- The vulnerable RXE code and the affected kernel resources share the same security authority. Kernel compromise or privilege escalation does not inherently cross a CVSS scope boundary.
- C:HConfidentiality impact, high
- The failure path frees a still-live queue, and shared uobject lookup permits concurrent modify operations to retain and use that freed queue. Heap reclamation can turn this use-after-free and associated double release into kernel-memory disclosure primitives.
- I:HIntegrity impact, high
- A concurrent resize can reach resize_finish() with the freed queue, where swap() writes a complete queue header into freed or reallocated slab memory and cleanup can release stale resources again. This provides defensible kernel heap corruption and potential control-flow hijacking.
- A:HAvailability impact, high
- A sequential second modification deterministically dereferences the NULL queue and causes a kernel oops or panic. Concurrent use-after-free paths can likewise crash the system and are repeatable by the attacker.