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CVE-2024-57857
RDMA/siw: Remove direct link to net_device
Published 2025-01-15 (21 months ago) by the Linux kernel CNA. Subsystem drivers/infiniband. Debian urgency: not yet assigned.
Debian does not build this code. The per-release build detail is under "Where it lives" below.
What to do, per Debian release
Debian's own status for CVE-2024-57857 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 | 6.12.9-1 | Update the kernel and reboot. Fixed in 6.12.9-1. A running kernel keeps the old code until the machine restarts. |
| Debian 14forky | fixed | 6.12.9-1 | Update the kernel and reboot. Fixed in 6.12.9-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 6.12.9-1 | Update the kernel and reboot. Fixed in 6.12.9-1. A running kernel keeps the old code until the machine restarts. |
The vulnerability
What the bug is
Do not manage a per device direct link to net_device. Rely on associated ib_devices net_device management, not doubling the effort locally. A badly managed local link to net_device was causing a 'KASAN: slab-use-after-free' exception during siw_query_port() call.
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/siw/siw.h
drivers/infiniband/sw/siw/siw_cm.c
drivers/infiniband/sw/siw/siw_main.c
drivers/infiniband/sw/siw/siw_verbs.c
- What this is
- SOFT-IWARP DRIVER (siw)MAINTAINERS section matched on drivers/infiniband/sw/siw/ · linux-rdma@vger.kernel.org · Supported
- Kernel module
- none to look for. The file would have gone into siw, and Debian does not compile it into that module, so finding siw in lsmod would say nothing about this CVE.
Check it on the machine
grep -wE 'CONFIG_INFINIBAND|CONFIG_RDMA_SIW' /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.
Show whether Debian builds this, per release
Debian does not build this code. In 4 releases below, every kernel flavour Debian publishes has the switch off, so the vulnerable file is compiled into no kernel binary Debian ships.
- bookworm, trixie, forky, sidn
- n
- not enabled on any flavour - this release does not build the code
- Build switches
- CONFIG_INFINIBAND, CONFIG_RDMA_SIW
- 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
- 2025-01-15 (21 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
- 0.21%, higher than 11.0% 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 |
|---|---|---|
| 5.3 | 6.12.9 | 4eafeb4f021c |
| 5.3 | 6.13 | 16b87037b488 |
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 dangling `sdev->netdev` is only dereferenced from local paths — sysfs port attribute reads, NETLINK_RDMA `PORT_GET`, uverbs `query_port`/`query_qp`, `rdma_listen()`, and the in-kernel ib_cache work triggered by local netdev teardown. No remote peer data or received packet reaches these sites.
- AC:LAttack complexity, low
- The attacker drives both sides of the race — generating port events (netdev up/down/changeaddr) that queue the `ib_cache_event_task`, and tearing down the netdev/netns that frees the `net_device` — and can repeat the sequence indefinitely while spamming `query_port` via sysfs/netlink, so the window is reachable on demand (syzbot reproduced it).
- PR:LPrivileges required, low
- The code that dereferences the freed pointer is reachable with zero privileges (world-readable `/sys/class/infiniband/*/ports/1/state`, unprivileged `RDMA_NLDEV_CMD_PORT_GET`, `ibv_query_port`), and the netdev-teardown side needs only `CAP_NET_ADMIN` within a network namespace, which an unprivileged user obtains via `unshare -Urn`; no real root in the initial namespace is required to reach the vulnerable dereference.
- UI:NUser interaction, none
- No victim action is needed — the attacker performs the device/netdev teardown and the query itself, or simply races the kernel's own asynchronous cache-update work.
- S:UScope, unchanged
- The use-after-free is confined to kernel memory within the same security authority; there is no VM, IOMMU, or sandbox boundary crossed.
- C:HConfidentiality impact, high
- This is a use-after-free read of a freed `struct net_device` slab object whose contents can be groomed by the attacker, and the read values are returned to userspace through `attr->max_mtu`/`active_mtu` and `qp_attr->path_mtu`, giving a controllable read of reclaimed kernel memory.
- I:HIntegrity impact, high
- Per use-after-free handling, the dangling pointer is not merely read but its contents feed kernel state — `siw_create_listen()` writes freed memory into `sk->sk_bound_dev_if` — and a UAF on a sprayable slab object is the standard primitive for heap grooming and control-flow corruption.
- A:HAvailability impact, high
- The confirmed outcome is a KASAN slab-use-after-free during `siw_query_port()`; dereferencing a stale `net_device` pointer into reclaimed or unmapped memory oopses/panics the kernel, and the trigger can be repeated at will.