In the Linux kernel, the following vulnerability has been resolved:
net/mlx5: LAG, fix logic over MLX5_LAG_FLAG_NDEVS_READY
Only set MLX5_LAG_FLAG_NDEVS_READY if both netdevices are registered.
Doing so guarantees that both ldev->pf[MLX5_LAG_P0].dev and
ldev->pf[MLX5_LAG_P1].dev have valid pointers when
MLX5_LAG_FLAG_NDEVS_READY is set.
The core issue is asymmetry in setting MLX5_LAG_FLAG_NDEVS_READY and
clearing it. Setting it is done wrongly when both
ldev->pf[MLX5_LAG_P0].dev and ldev->pf[MLX5_LAG_P1].dev are set;
clearing it is done right when either of ldev->pf[i].netdev is cleared.
Consider the following scenario:
- PF0 loads and sets ldev->pf[MLX5_LAG_P0].dev to a valid pointer
- PF1 loads and sets both ldev->pf[MLX5_LAG_P1].dev and
ldev->pf[MLX5_LAG_P1].netdev with valid pointers. This results in
MLX5_LAG_FLAG_NDEVS_READY is set.
- PF0 is unloaded before setting dev->pf[MLX5_LAG_P0].netdev.
MLX5_LAG_FLAG_NDEVS_READY remains set.
Further execution of mlx5_do_bond() will result in null pointer
dereference when calling mlx5_lag_is_multipath()
This patch fixes the following call trace actually encountered:
[ 1293.475195] BUG: kernel NULL pointer dereference, address: 00000000000009a8
[ 1293.478756] #PF: supervisor read access in kernel mode
[ 1293.481320] #PF: error_code(0x0000) - not-present page
[ 1293.483686] PGD 0 P4D 0
[ 1293.484434] Oops: 0000 [#1] SMP PTI
[ 1293.485377] CPU: 1 PID: 23690 Comm: kworker/u16:2 Not tainted 5.18.0-rc5_for_upstream_min_debug_2022_05_05_10_13 #1
[ 1293.488039] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
[ 1293.490836] Workqueue: mlx5_lag mlx5_do_bond_work [mlx5_core]
[ 1293.492448] RIP: 0010:mlx5_lag_is_multipath+0x5/0x50 [mlx5_core]
[ 1293.494044] Code: e8 70 40 ff e0 48 8b 14 24 48 83 05 5c 1a 1b 00 01 e9 19 ff ff ff 48 83 05 47 1a 1b 00 01 eb d7 0f 1f 44 00 00 0f 1f 44 00 00 <48> 8b 87 a8 09 00 00 48 85 c0 74 26 48 83 05 a7 1b 1b 00 01 41 b8
[ 1293.498673] RSP: 0018:ffff88811b2fbe40 EFLAGS: 00010202
[ 1293.500152] RAX: ffff88818a94e1c0 RBX: ffff888165eca6c0 RCX: 0000000000000000
[ 1293.501841] RDX: 0000000000000001 RSI: ffff88818a94e1c0 RDI: 0000000000000000
[ 1293.503585] RBP: 0000000000000000 R08: ffff888119886740 R09: ffff888165eca73c
[ 1293.505286] R10: 0000000000000018 R11: 0000000000000018 R12: ffff88818a94e1c0
[ 1293.506979] R13: ffff888112729800 R14: 0000000000000000 R15: ffff888112729858
[ 1293.508753] FS: 0000000000000000(0000) GS:ffff88852cc40000(0000) knlGS:0000000000000000
[ 1293.510782] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1293.512265] CR2: 00000000000009a8 CR3: 00000001032d4002 CR4: 0000000000370ea0
[ 1293.514001] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 1293.515806] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (5.5): severity, escalated by confirmed exploitation. This CVE's 5.5 is its impact severity (EG Severity), not escalated.
- EG Severity
- 5.5 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
- EG Likelihood
- 0.2% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-25). FIRST's exploitation probability, not an EchelonGraph model.
- Confirmed exploitation
- None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
- EG Priority
- SSVC Track at medium mission impactTrack at low or medium mission impact; Track* at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.
SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).
A fix is available. Apply it within your standard update timelines.
Exploitation none (no CISA value, KEV listing or exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from Vulnrichment. EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table
BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.
The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). Where an input reads “CISA's BOD 26-04 default”, no one has published it for this CVE, and CISA's implementation guidance says: “If “Automatable” and “Technical Impact” information items about a CVE ID are not available and the CVE ID is not in the KEV Catalog, CISA will treat its values as “no” and “total,” respectively, until CISA or a third party provides metadata about the CVE ID. CISA will always provide the Vulnrichment data for a CVE ID listed in the KEV Catalog.” Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it