Description
In the Linux kernel, the following vulnerability has been resolved:
net: drop_monitor: fix info leak in NET_DM_ATTR_PAYLOAD
net_dm_packet_report_fill() and net_dm_hw_packet_report_fill() open code
the NET_DM_ATTR_PAYLOAD attribute to avoid zeroing the packet payload
before overwriting it with skb_copy_bits().
skb_put() reserves nla_total_size(payload_len), i.e. the header plus the
NLA_ALIGN() padding, but only payload_len bytes are copied in. When
payload_len is not a multiple of 4 the 1-3 padding bytes are never
initialized and are leaked to user space inside the netlink message.
KMSAN confirms the leak for the software path when the packet payload
length is not 4-byte aligned:
BUG: KMSAN: kernel-infoleak in _copy_to_iter
_copy_to_iter
__skb_datagram_iter
skb_copy_datagram_iter
netlink_recvmsg
sock_recvmsg
__sys_recvfrom
Uninit was created at:
kmem_cache_alloc_node_noprof
__alloc_skb
net_dm_packet_work
Bytes 173-175 of 176 are uninitialized
Use __nla_reserve(), which sets up the attribute header and zeroes the
padding, instead of open coding the attribute construction.
net: drop_monitor: fix info leak in NET_DM_ATTR_PAYLOAD
net_dm_packet_report_fill() and net_dm_hw_packet_report_fill() open code
the NET_DM_ATTR_PAYLOAD attribute to avoid zeroing the packet payload
before overwriting it with skb_copy_bits().
skb_put() reserves nla_total_size(payload_len), i.e. the header plus the
NLA_ALIGN() padding, but only payload_len bytes are copied in. When
payload_len is not a multiple of 4 the 1-3 padding bytes are never
initialized and are leaked to user space inside the netlink message.
KMSAN confirms the leak for the software path when the packet payload
length is not 4-byte aligned:
BUG: KMSAN: kernel-infoleak in _copy_to_iter
_copy_to_iter
__skb_datagram_iter
skb_copy_datagram_iter
netlink_recvmsg
sock_recvmsg
__sys_recvfrom
Uninit was created at:
kmem_cache_alloc_node_noprof
__alloc_skb
net_dm_packet_work
Bytes 173-175 of 176 are uninitialized
Use __nla_reserve(), which sets up the attribute header and zeroes the
padding, instead of open coding the attribute construction.
Published:
2026-08-10
Score:
n/a
EPSS:
n/a
KEV:
No
Impact:
n/a
Action:
n/a
No analysis available yet.
Remediation
No remediation available yet.
Tracking
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Advisories
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References
History
Mon, 10 Aug 2026 12:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: net: drop_monitor: fix info leak in NET_DM_ATTR_PAYLOAD net_dm_packet_report_fill() and net_dm_hw_packet_report_fill() open code the NET_DM_ATTR_PAYLOAD attribute to avoid zeroing the packet payload before overwriting it with skb_copy_bits(). skb_put() reserves nla_total_size(payload_len), i.e. the header plus the NLA_ALIGN() padding, but only payload_len bytes are copied in. When payload_len is not a multiple of 4 the 1-3 padding bytes are never initialized and are leaked to user space inside the netlink message. KMSAN confirms the leak for the software path when the packet payload length is not 4-byte aligned: BUG: KMSAN: kernel-infoleak in _copy_to_iter _copy_to_iter __skb_datagram_iter skb_copy_datagram_iter netlink_recvmsg sock_recvmsg __sys_recvfrom Uninit was created at: kmem_cache_alloc_node_noprof __alloc_skb net_dm_packet_work Bytes 173-175 of 176 are uninitialized Use __nla_reserve(), which sets up the attribute header and zeroes the padding, instead of open coding the attribute construction. | |
| Title | net: drop_monitor: fix info leak in NET_DM_ATTR_PAYLOAD | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-08-10T12:02:21.097Z
Reserved: 2026-07-30T09:28:09.380Z
Link: CVE-2026-68288
No data.
No data.
No data.
OpenCVE Enrichment
No data.
Weaknesses
No weakness.