CVE-2026-45970 — bonding: alb: fix UAF in rlb_arp_recv during bond up/down
In the Linux kernel, the following vulnerability has been resolved: bonding: alb: fix UAF in rlb_arp_recv during bond up/down The ALB RX path may access rx_hashtbl concurrently with bond teardown. During rapid bond up/down cycles, rlb_deinitialize() frees rx_hashtbl while RX handlers are still running, leading to a null pointer dereference detected by KASAN. However, the root cause is that rlb_arp_recv() can still be accessed after setting recv_probe to NULL, which is actually a use-after-free (UAF) issue. That is the reason for using the referenced commit in the Fixes tag. [ 214.174138] Oops: general protection fault, probably for non-canonical address 0xdffffc000000001d: 0000 [#1] SMP KASAN PTI [ 214.186478] KASAN: null-ptr-deref in range [0x00000000000000e8-0x00000000000000ef] [ 214.194933] CPU: 30 UID: 0 PID: 2375 Comm: ping Kdump: loaded Not tainted 6.19.0-rc8+ #2 PREEMPT(voluntary) [ 214.205907] Hardware name: Dell Inc. PowerEdge R730/0WCJNT, BIOS 2.14.0 01/14/2022 [ 214.214357] RIP: 0010:rlb_arp_recv+0x505/0xab0 [bonding] [ 214.220320] Code: 0f 85 2b 05 00 00 48 b8 00 00 00 00 00 fc ff df 40 0f b6 ed 48 c1 e5 06 49 03 ad 78 01 00 00 48 8d 7d 28 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 06 0f 8e 12 05 00 00 80 7d 28 00 0f 84 8c 00 [ 214.241280] RSP: 0018:ffffc900073d8870 EFLAGS: 00010206 [ 214.247116] RAX: dffffc0000000000 RBX: ffff888168556822 RCX: ffff88816855681e [ 214.255082] RDX: 000000000000001d RSI: dffffc0000000000 RDI: 00000000000000e8 [ 214.263048] RBP: 00000000000000c0 R08: 0000000000000002 R09: ffffed11192021c8 [ 214.271013] R10: ffff8888c9010e43 R11: 0000000000000001 R12: 1ffff92000e7b119 [ 214.278978] R13: ffff8888c9010e00 R14: ffff888168556822 R15: ffff888168556810 [ 214.286943] FS: 00007f85d2d9cb80(0000) GS:ffff88886ccb3000(0000) knlGS:0000000000000000 [ 214.295966] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 214.302380] CR2: 00007f0d047b5e34 CR3: 00000008a1c2e002 CR4: 00000000001726f0 [ 214.310347] Call Trace: [ 214.313070] <IRQ> [ 214.315318] ? __pfx_rlb_arp_recv+0x10/0x10 [bonding] [ 214.320975] bond_handle_frame+0x166/0xb60 [bonding] [ 214.326537] ? __pfx_bond_handle_frame+0x10/0x10 [bonding] [ 214.332680] __netif_receive_skb_core.constprop.0+0x576/0x2710 [ 214.339199] ? __pfx_arp_process+0x10/0x10 [ 214.343775] ? sched_balance_find_src_group+0x98/0x630 [ 214.349513] ? __pfx___netif_receive_skb_core.constprop.0+0x10/0x10 [ 214.356513] ? arp_rcv+0x307/0x690 [ 214.360311] ? __pfx_arp_rcv+0x10/0x10 [ 214.364499] ? __lock_acquire+0x58c/0xbd0 [ 214.368975] __netif_receive_skb_one_core+0xae/0x1b0 [ 214.374518] ? __pfx___netif_receive_skb_one_core+0x10/0x10 [ 214.380743] ? lock_acquire+0x10b/0x140 [ 214.385026] process_backlog+0x3f1/0x13a0 [ 214.389502] ? process_backlog+0x3aa/0x13a0 [ 214.394174] __napi_poll.constprop.0+0x9f/0x370 [ 214.399233] net_rx_action+0x8c1/0xe60 [ 214.403423] ? __pfx_net_rx_action+0x10/0x10 [ 214.408193] ? lock_acquire.part.0+0xbd/0x260 [ 214.413058] ? sched_clock_cpu+0x6c/0x540 [ 214.417540] ? mark_held_locks+0x40/0x70 [ 214.421920] handle_softirqs+0x1fd/0x860 [ 214.426302] ? __pfx_handle_softirqs+0x10/0x10 [ 214.431264] ? __neigh_event_send+0x2d6/0xf50 [ 214.436131] do_softirq+0xb1/0xf0 [ 214.439830] </IRQ> The issue is reproducible by repeatedly running ip link set bond0 up/down while receiving ARP messages, where rlb_arp_recv() can race with rlb_deinitialize() and dereference a freed rx_hashtbl entry. Fix this by setting recv_probe to NULL and then calling synchronize_net() to wait for any concurrent RX processing to finish. This ensures that no RX handler can access rx_hashtbl after it is freed in bond_alb_deinitialize().
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.1% (30-day exploitation probability)+0
- Technical severity (high)+6
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Linux Linux, Linux Linux Kernel).
- Apply the fixed version or the patch documented under Remediation.
- Search available logs for exploit probes matching the vulnerability class (memory corruption), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Linux | Linux |
≥ 3aba891dde3842d89ad022237b99c1ed308040b0 and < fd54ddc929be1d6c3b3b7b35d6d4642a5d9e803c≥ 3aba891dde3842d89ad022237b99c1ed308040b0 and < de7c097800f07f3c108185c7a38b53a530ba30ff≥ 3aba891dde3842d89ad022237b99c1ed308040b0 and < db5435b5342e3aaa4521d0f3ccfe94316b253ca1≥ 3aba891dde3842d89ad022237b99c1ed308040b0 and < f94a0de7b9f32745a14a1621c63087a092823587≥ 3aba891dde3842d89ad022237b99c1ed308040b0 and < c65cdf46ce340c9c00fbbaf84599d2daff43626e≥ 3aba891dde3842d89ad022237b99c1ed308040b0 and < fef13c403be3fb685cb06419e6b3623106aab5ba≥ 3aba891dde3842d89ad022237b99c1ed308040b0 and < d31065526f160ee0244a719230aa069daca2bf4d≥ 3aba891dde3842d89ad022237b99c1ed308040b0 and < e6834a4c474697df23ab9948fd3577b26bf48656 and 1 moreversion 3.0 |
Vulnerable | CVE Program (cve.org) e CISA ADP |
| Linux | Linux Kernel | ≥ 3.0 and < 5.10.252≥ 5.11 and < 5.15.202≥ 5.16 and < 6.1.165≥ 6.2 and < 6.6.128≥ 6.7 and < 6.12.75≥ 6.13 and < 6.18.14≥ 6.19 and < 6.19.4 | Vulnerable | NIST National Vulnerability Database |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 7.8 | CVSS 3.1 | High | 1.8 | 5.9 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 via NIST National Vulnerability Database |
| 7.8 | CVSS 3.1 | High | — | — | Linux via CVE Program (cve.org) e CISA ADP |
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H (score shown at the top: 416baaa9-dc9f-4396-8d5f-8c081fb06d67) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
EPSS over time FIRST
Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.13%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
- Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · linux/linux
- Record published
- Fix documented
- CVSS changed · 7.8
- Source status changed · → Analyzed
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 13, 2026 – Oct 13, 2026
References
8 on the record
- git.kernel.org/stable/c/c65cdf46ce340c9c00fbbaf84599d2daff43626e
- git.kernel.org/stable/c/db5435b5342e3aaa4521d0f3ccfe94316b253ca1
- git.kernel.org/stable/c/f94a0de7b9f32745a14a1621c63087a092823587
- git.kernel.org/stable/c/fef13c403be3fb685cb06419e6b3623106aab5ba
- git.kernel.org/stable/c/fd54ddc929be1d6c3b3b7b35d6d4642a5d9e803c
- git.kernel.org/stable/c/d31065526f160ee0244a719230aa069daca2bf4d
- git.kernel.org/stable/c/de7c097800f07f3c108185c7a38b53a530ba30ff
- git.kernel.org/stable/c/e6834a4c474697df23ab9948fd3577b26bf48656
Elsewhere on this site
Related CVEs (same products)
- Critical CVE-2026-99999 ipv4: validate checksum_start before completing checksum 9h
- Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 9h
- Unknown CVE-2026-98424 wifi: cfg80211: undo netns switch if renaming the wiphy fails 1d
- Unknown CVE-2026-98425 wifi: mac80211: don't warn when an IBSS has no channel to scan 1d
- Unknown CVE-2026-98426 wifi: mwifiex: fix IRQ leak using wrong index in MSI-X error path 1d
- Unknown CVE-2026-98427 net/sched: codel: bound the dropping loop per dequeue call 1d
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No CISA SSVC assessment.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-45970 is "bonding: alb: fix UAF in rlb_arp_recv during bond up/down", rated High. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 7.8 describes technical severity. EPSS 0.13% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
Comments
Moderated technical discussion. Read the community guidelines.
No comments yet.
Sign in or create an account to comment and suggest corrections.