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CVE-2026-99033

net/packet: guard the ll header push in packet_rcv_spkt()

Products / packages Linux

Published

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Severity and exploitation

Not in CISA KEVNo CVSS score

KEV coverage does not rule out exploitation.

KEV checked 14/11/2026, 21:25:33 UTC

Severity

unknown

CVSS measures technical severity, not the likelihood of an attack.

Known exploitation

Not listed in the checked CISA KEV catalog

Absence from CISA KEV does not rule out attacks.

Public exploit

Not established by this record

Missing evidence does not mean no public exploit exists.

Remediation

Fix status not established

No structured fix or guidance is available here. Check the latest publisher advisory.

What this means

In the Linux kernel, the following vulnerability has been resolved:

Source excerpt · Linux

Attack conditions

No attack-condition excerpt has been identified here. Review the full source description and references for authentication, network access, and configuration requirements.

Review supporting sources →

Affected versions

Check the exact model, release, and any platform requirements against your installation.

Linux · Linux

Linux

10 ranges
Linux version evidence

Compare with this publisher’s ranges. This does not inspect your installation.

affected

d549699048b4b5c22dd710455bcdb76966e55aa3 → before 48aa1155fa8d83362fc33d02d527a3c3fe40ce1c

git versions

d549699048b4b5c22dd710455bcdb76966e55aa3 → before 7f84ed94ccfe36091234a2891b88356dc06e6d66

git versions

d549699048b4b5c22dd710455bcdb76966e55aa3 → before b880df0e487caa85c3c7ffda37dcd05334b1aa80

git versions

d549699048b4b5c22dd710455bcdb76966e55aa3 → before d8a24b9e1774a93943caf68d48c5e17be432220b

git versions

d549699048b4b5c22dd710455bcdb76966e55aa3 → before 31c7b15b3716e8d0dad58d2c3cdf321dfd06f4be

git versions

d549699048b4b5c22dd710455bcdb76966e55aa3 → before 3efe0e0944157fdd2072b4dc7eb0491a317ed272

git versions

d549699048b4b5c22dd710455bcdb76966e55aa3 → before 00fbf71e74115f7628fc0880b855434b1e70c40c

git versions

d549699048b4b5c22dd710455bcdb76966e55aa3 → before 28bc1ef699610ee09ce3d46a00552f5a0a0144bd

git versions

dadddde259a19105ee69e788835f4d4552767aa9

git versions

5.9.13 → before 5.10

semver versions

unaffected

unknown

Other versions: unaffected

Linux · Linux

Linux

10 ranges
Linux version evidence

Compare with this publisher’s ranges. This does not inspect your installation.

affected

5.10

unaffected

0 → before 5.10

semver versions

5.10.273 → through 5.10.*

semver versions

5.15.224 → through 5.15.*

semver versions

6.1.191 → through 6.1.*

semver versions

6.6.160 → through 6.6.*

semver versions

6.12.113 → through 6.12.*

semver versions

6.18.57 → through 6.18.*

semver versions

7.2.11 → through 7.2.*

semver versions

7.3 → through *

original_commit_for_fix versions

unknown

Other versions: affected

Automatic dependency matching is unavailable for this record. Use the product evidence and publisher’s instructions to check your installation.

What to do

Compare your installed product and version with the affected versions above. A matching product name alone does not confirm exposure.

No structured fix or remediation guidance is available here. Check the full source description and vendor’s latest advisory for a patch or workaround; do not assume another version is safe.

cve.new guidance unless attributed to a publisher. This page does not inspect your installation.

Public exploit evidence

No public exploit reference is identified in the imported evidence. This is not a claim that no exploit exists.

Original source description

Read the full publisher description

In the Linux kernel, the following vulnerability has been resolved:

net/packet: guard the ll header push in packet_rcv_spkt()

packet_rcv_spkt() restores the link layer header with

skb_push(skb, skb->data - skb_mac_header(skb));

That subtraction is only meaningful when the device actually has a link layer header. packet_rcv() and tpacket_rcv() both wrap it in dev_has_header(), which is also the predicate the block comment at the top of the file states the restore in terms of; packet_rcv_spkt() does not. commit d549699048b4 ("net/packet: fix packet receive on L3 devices without visible hard header") introduced the helper and changed the two call sites, and this one stayed behind.

A device without a visible ll header can leave skb->mac_header at the 0xFFFF sentinel that _alloc_skb() initialises it to. A CAN skb does: init_can_skb() sets pkt_type and ip_summed but does not reset the headers, and commit 9f10374bb024 ("can: remove private CAN skb headroom infrastructure") dropped the skb_reset*_header() calls that used to be there. skb_mac_header() is then 0xFFFF, the length becomes a large negative number and skb_push() reports it through skb_under_panic() -- from softirq context, so it is a full system panic even with panic_on_oops=0:

skbuff: skb_under_panic: text:ffffffff8bd21bc1 len:-65455 put:-65471 head:... data:... tail:0x50 end:0x180 dev:can0 kernel BUG at net/core/skbuff.c:214! RIP: 0010:skb_panic+0x50/0x60 Call Trace: <IRQ> skb_push+0x38/0x40 packet_rcv_spkt+0xe1/0x170 __netif_receive_skb_core.constprop.0+0x7e8/0xd30 ... Kernel panic - not syncing: Fatal exception in interrupt

The socket type is reachable: packet_create() accepts SOCK_PACKET alongside SOCK_RAW and SOCK_DGRAM behind the same CAP_NET_RAW check, and neither the socket length nor a capability check keeps it away from a CAN interface.

The missing skb_reset_*_header() calls in init_can_skb() are a regression in their own right and are being fixed separately, but a packet socket should not turn a link layer that did not initialise its mac header into a kernel panic. Guard the push the way the other two receive paths do.

Tested on v7.3-rc5 under QEMU with a slcan device on a pty, which is the driver RX path: vcan does not reproduce it, because can_send() resets the headers on the way out. One SOCK_PACKET socket bound to can0 and one frame written into the line discipline panics an unpatched kernel with the trace above; the same image with this patch prints no panic and powers off normally. Both kernels are this tree, defconfig plus CONFIG_CAN_SLCAN=y, differing only in this hunk.

References

8 sources
git.kernel.org/stable/c/48aa1155fa8d83362fc33d02d527a3c3fe40ce1c
Source referenceLinux
git.kernel.org/stable/c/7f84ed94ccfe36091234a2891b88356dc06e6d66
Source referenceLinux
git.kernel.org/stable/c/b880df0e487caa85c3c7ffda37dcd05334b1aa80
Source referenceLinux
git.kernel.org/stable/c/d8a24b9e1774a93943caf68d48c5e17be432220b
Source referenceLinux
git.kernel.org/stable/c/31c7b15b3716e8d0dad58d2c3cdf321dfd06f4be
Source referenceLinux
git.kernel.org/stable/c/3efe0e0944157fdd2072b4dc7eb0491a317ed272
Source referenceLinux
View 2 more references
git.kernel.org/stable/c/00fbf71e74115f7628fc0880b855434b1e70c40c
Source referenceLinux
git.kernel.org/stable/c/28bc1ef699610ee09ce3d46a00552f5a0a0144bd
Source referenceLinux

Inside the record

Evidence available

Package identity · not supplied
Version evidence
Remediation guidance · not supplied
Weakness classification · not supplied
Additional publishers · not supplied

Describes the evidence in this view, not whether the product is safe.

Original records

CVE-2026-99033

View the latest unmodified CVE JSON from the official source. It may be newer than this imported page.

cve.new JSON →

Environment requirements

These conditions apply together as specified by the publisher. A matching product name alone does not establish exposure.

Linux · platform conditions

Any condition may hold

Vulnerable product

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

From (inclusive): 5.10

Before: 5.10.273

Vulnerable product

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

From (inclusive): 5.10

Before: 5.15.224

Vulnerable product

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

From (inclusive): 5.10

Before: 6.1.191

Vulnerable product

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

From (inclusive): 5.10

Before: 6.6.160

Vulnerable product

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

From (inclusive): 5.10

Before: 6.12.113

Vulnerable product

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

From (inclusive): 5.10

Before: 6.18.57

Vulnerable product

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

From (inclusive): 5.10

Before: 7.2.11

Vulnerable product

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

From (inclusive): 5.10

Before: 7.3

Vulnerable product

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

From (inclusive): 5.9.13

Applicability preview
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            "vulnerable": true,
            "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
            "versionStartIncluding": "5.10",
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Contributing organizations · 1
Linux

Assigning organization

2026-10-30

Timeline

All times UTC

  1. Advisory published

    Publication date supplied by the source.

  2. Source updated

    Latest modification date supplied by the source.

  3. Last imported by cve.new

    Latest catalog import, not the date we first saw this advisory.

What changed

Follow changes
No substantive changes have been recorded here yet. History starts when cve.new observes a change after tracking is enabled; earlier edits are not reconstructed.

Large field values are marked as truncated previews. Original source snapshots remain retained.