In the Linux kernel, the following vulnerability has been resolved:
hsr: Fix uninit-value access in fill_frame_info()
Syzbot reports the following uninit-value access problem.
=====================================================
BUG: KMSAN: uninit-value in fill_frame_info net/hsr/hsr_forward.c:601 [inline]
BUG: KMSAN: uninit-value in hsr_forward_skb+0x9bd/0x30f0 net/hsr/hsr_forward.c:616
fill_frame_info net/hsr/hsr_forward.c:601 [inline]
hsr_forward_skb+0x9bd/0x30f0 net/hsr/hsr_forward.c:616
hsr_dev_xmit+0x192/0x330 net/hsr/hsr_device.c:223
__netdev_start_xmit include/linux/netdevice.h:4889 [inline]
netdev_start_xmit include/linux/netdevice.h:4903 [inline]
xmit_one net/core/dev.c:3544 [inline]
dev_hard_start_xmit+0x247/0xa10 net/core/dev.c:3560
__dev_queue_xmit+0x34d0/0x52a0 net/core/dev.c:4340
dev_queue_xmit include/linux/netdevice.h:3082 [inline]
packet_xmit+0x9c/0x6b0 net/packet/af_packet.c:276
packet_snd net/packet/af_packet.c:3087 [inline]
packet_sendmsg+0x8b1d/0x9f30 net/packet/af_packet.c:3119
sock_sendmsg_nosec net/socket.c:730 [inline]
sock_sendmsg net/socket.c:753 [inline]
__sys_sendto+0x781/0xa30 net/socket.c:2176
__do_sys_sendto net/socket.c:2188 [inline]
__se_sys_sendto net/socket.c:2184 [inline]
__ia32_sys_sendto+0x11f/0x1c0 net/socket.c:2184
do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline]
__do_fast_syscall_32+0xa2/0x100 arch/x86/entry/common.c:178
do_fast_syscall_32+0x37/0x80 arch/x86/entry/common.c:203
do_SYSENTER_32+0x1f/0x30 arch/x86/entry/common.c:246
entry_SYSENTER_compat_after_hwframe+0x70/0x82
Uninit was created at:
slab_post_alloc_hook+0x12f/0xb70 mm/slab.h:767
slab_alloc_node mm/slub.c:3478 [inline]
kmem_cache_alloc_node+0x577/0xa80 mm/slub.c:3523
kmalloc_reserve+0x148/0x470 net/core/skbuff.c:559
__alloc_skb+0x318/0x740 net/core/skbuff.c:644
alloc_skb include/linux/skbuff.h:1286 [inline]
alloc_skb_with_frags+0xc8/0xbd0 net/core/skbuff.c:6299
sock_alloc_send_pskb+0xa80/0xbf0 net/core/sock.c:2794
packet_alloc_skb net/packet/af_packet.c:2936 [inline]
packet_snd net/packet/af_packet.c:3030 [inline]
packet_sendmsg+0x70e8/0x9f30 net/packet/af_packet.c:3119
sock_sendmsg_nosec net/socket.c:730 [inline]
sock_sendmsg net/socket.c:753 [inline]
__sys_sendto+0x781/0xa30 net/socket.c:2176
__do_sys_sendto net/socket.c:2188 [inline]
__se_sys_sendto net/socket.c:2184 [inline]
__ia32_sys_sendto+0x11f/0x1c0 net/socket.c:2184
do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline]
__do_fast_syscall_32+0xa2/0x100 arch/x86/entry/common.c:178
do_fast_syscall_32+0x37/0x80 arch/x86/entry/common.c:203
do_SYSENTER_32+0x1f/0x30 arch/x86/entry/common.c:246
entry_SYSENTER_compat_after_hwframe+0x70/0x82
It is because VLAN not yet supported in hsr driver. Return error
when protocol is ETH_P_8021Q in fill_frame_info() now to fix 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 (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. 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: 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.
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