In the Linux kernel, the following vulnerability has been resolved:
net: bgmac: Fix a BUG triggered by wrong bytes_compl
On one of our machines we got:
kernel BUG at lib/dynamic_queue_limits.c:27!
Internal error: Oops - BUG: 0 [#1] PREEMPT SMP ARM
CPU: 0 PID: 1166 Comm: irq/41-bgmac Tainted: G W O 4.14.275-rt132 #1
Hardware name: BRCM XGS iProc
task: ee3415c0 task.stack: ee32a000
PC is at dql_completed+0x168/0x178
LR is at bgmac_poll+0x18c/0x6d8
pc : [] lr : [] psr: 800a0313
sp : ee32be14 ip : 000005ea fp : 00000bd4
r10: ee558500 r9 : c0116298 r8 : 00000002
r7 : 00000000 r6 : ef128810 r5 : 01993267 r4 : 01993851
r3 : ee558000 r2 : 000070e1 r1 : 00000bd4 r0 : ee52c180
Flags: Nzcv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none
Control: 12c5387d Table: 8e88c04a DAC: 00000051
Process irq/41-bgmac (pid: 1166, stack limit = 0xee32a210)
Stack: (0xee32be14 to 0xee32c000)
be00: ee558520 ee52c100 ef128810
be20: 00000000 00000002 c0116298 c04b5a18 00000000 c0a0c8c4 c0951780 00000040
be40: c0701780 ee558500 ee55d520 ef05b340 ef6f9780 ee558520 00000001 00000040
be60: ffffe000 c0a56878 ef6fa040 c0952040 0000012c c0528744 ef6f97b0 fffcfb6a
be80: c0a04104 2eda8000 c0a0c4ec c0a0d368 ee32bf44 c0153534 ee32be98 ee32be98
bea0: ee32bea0 ee32bea0 ee32bea8 ee32bea8 00000000 c01462e4 ffffe000 ef6f22a8
bec0: ffffe000 00000008 ee32bee4 c0147430 ffffe000 c094a2a8 00000003 ffffe000
bee0: c0a54528 00208040 0000000c c0a0c8c4 c0a65980 c0124d3c 00000008 ee558520
bf00: c094a23c c0a02080 00000000 c07a9910 ef136970 ef136970 ee30a440 ef136900
bf20: ee30a440 00000001 ef136900 ee30a440 c016d990 00000000 c0108db0 c012500c
bf40: ef136900 c016da14 ee30a464 ffffe000 00000001 c016dd14 00000000 c016db28
bf60: ffffe000 ee21a080 ee30a400 00000000 ee32a000 ee30a440 c016dbfc ee25fd70
bf80: ee21a09c c013edcc ee32a000 ee30a400 c013ec7c 00000000 00000000 00000000
bfa0: 00000000 00000000 00000000 c0108470 00000000 00000000 00000000 00000000
bfc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
bfe0: 00000000 00000000 00000000 00000000 00000013 00000000 00000000 00000000
[] (dql_completed) from [] (bgmac_poll+0x18c/0x6d8)
[] (bgmac_poll) from [] (net_rx_action+0x1c4/0x494)
[] (net_rx_action) from [] (do_current_softirqs+0x1ec/0x43c)
[] (do_current_softirqs) from [] (__local_bh_enable+0x80/0x98)
[] (__local_bh_enable) from [] (irq_forced_thread_fn+0x84/0x98)
[] (irq_forced_thread_fn) from [] (irq_thread+0x118/0x1c0)
[] (irq_thread) from [] (kthread+0x150/0x158)
[] (kthread) from [] (ret_from_fork+0x14/0x24)
Code: a83f15e0 0200001a 0630a0e1 c3ffffea (f201f0e7)
The issue seems similar to commit 90b3b339364c ("net: hisilicon: Fix a BUG
trigered by wrong bytes_compl") and potentially introduced by commit
b38c83dd0866 ("bgmac: simplify tx ring index handling").
If there is an RX interrupt between setting ring->end
and netdev_sent_queue() we can hit the BUG_ON as bgmac_dma_tx_free()
can miscalculate the queue size while called from bgmac_poll().
The machine which triggered the BUG runs a v4.14 RT kernel - but the issue
seems present in mainline too.
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
- 0.4% 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