In the Linux kernel, the following vulnerability has been resolved:
wifi: rsi: Fix memory corruption due to not set vif driver data size
The struct ieee80211_vif contains trailing space for vif driver data,
when struct ieee80211_vif is allocated, the total memory size that is
allocated is sizeof(struct ieee80211_vif) + size of vif driver data.
The size of vif driver data is set by each WiFi driver as needed.
The RSI911x driver does not set vif driver data size, no trailing space
for vif driver data is therefore allocated past struct ieee80211_vif .
The RSI911x driver does however use the vif driver data to store its
vif driver data structure "struct vif_priv". An access to vif->drv_priv
leads to access out of struct ieee80211_vif bounds and corruption of
some memory.
In case of the failure observed locally, rsi_mac80211_add_interface()
would write struct vif_priv *vif_info = (struct vif_priv *)vif->drv_priv;
vif_info->vap_id = vap_idx. This write corrupts struct fq_tin member
struct list_head new_flows . The flow = list_first_entry(head, struct
fq_flow, flowchain); in fq_tin_reset() then reports non-NULL bogus
address, which when accessed causes a crash.
The trigger is very simple, boot the machine with init=/bin/sh , mount
devtmpfs, sysfs, procfs, and then do "ip link set wlan0 up", "sleep 1",
"ip link set wlan0 down" and the crash occurs.
Fix this by setting the correct size of vif driver data, which is the
size of "struct vif_priv", so that memory is allocated and the driver
can store its driver data in it, instead of corrupting memory around
it.
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (7.8): severity, escalated by confirmed exploitation. This CVE's 7.8 is its impact severity (EG Severity), not escalated.
- EG Severity
- 7.8 HIGHCVSS-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. 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 (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (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 Vulnrichment) · Technical impact total (CISA Vulnrichment). 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