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Bottlerocket: kernel-5.10: security update to 5.10.227kernel-5.15: security update to 5.15.168
medium Tenable Cloud Security Plugin ID 428059
Description
There are packages installed that are affected by a vulnerability referenced in the following CVE:- In the Linux kernel, the following vulnerability has been resolved: inet: inet_defrag: prevent sk release
while still in use ip_local_out() and other functions can pass skb->sk as function argument. If the skb is
a fragment and reassembly happens before such function call returns, the sk must not be released. This
affects skb fragments reassembled via netfilter or similar modules, e.g. openvswitch or ct_act.c, when run
as part of tx pipeline. Eric Dumazet made an initial analysis of this bug. Quoting Eric: Calling
ip_defrag() in output path is also implying skb_orphan(), which is buggy because output path relies on sk
not disappearing. A relevant old patch about the issue was : 8282f27449bf ("inet: frag: Always orphan skbs
inside ip_defrag()") [..] net/ipv4/ip_output.c depends on skb->sk being set, and probably to an inet
socket, not an arbitrary one. If we orphan the packet in ipvlan, then downstream things like FQ packet
scheduler will not work properly. We need to change ip_defrag() to only use skb_orphan() when really
needed, ie whenever frag_list is going to be used. Eric suggested to stash sk in fragment queue and made
an initial patch. However there is a problem with this: If skb is refragmented again right after,
ip_do_fragment() will copy head->sk to the new fragments, and sets up destructor to sock_wfree. IOW, we
have no choice but to fix up sk_wmem accouting to reflect the fully reassembled skb, else wmem will
underflow. This change moves the orphan down into the core, to last possible moment. As ip_defrag_offset
is aliased with sk_buff->sk member, we must move the offset into the FRAG_CB, else skb->sk gets clobbered.
This allows to delay the orphaning long enough to learn if the skb has to be queued or if the skb is
completing the reasm queue. In the former case, things work as before, skb is orphaned. This is safe
because skb gets queued/stolen and won't continue past reasm engine. In the latter case, we will steal the
skb->sk reference, reattach it to the head skb, and fix up wmem accouting when inet_frag inflates
truesize. (CVE-2024-26921)
Plugin Details
Severity: Medium
ID: 428059
Version: Revision 1.4
Type: Local
Published: 6/30/2025
Updated: 9/18/2025
Supported Sensors: Tenable Cloud Security, Tenable Self-Hosted Container Security
Risk Information
VPR
Risk Factor: Low
Score: 3
Percentile: 23.18
CVSS v2
Risk Factor: Medium
Base Score: 4.6
Temporal Score: 3.4
Vector: CVSS2#AV:L/AC:L/Au:S/C:N/I:N/A:C
CVSS Score Source: CVE-2024-26921
CVSS v3
Risk Factor: Medium
Base Score: 5.5
Temporal Score: 4.8
Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C
Vulnerability Information
Exploit Ease: No known exploits are available
Vulnerability Publication Date: 4/18/2024
Reference Information
CVE: CVE-2024-26921