CVE-2024-44933: bnxt_en : Fix memory out-of-bounds in bnxt_fill_hw_rss_tbl()
In the Linux kernel, the following vulnerability has been resolved:
bnxt_en : Fix memory out-of-bounds in bnxt_fill_hw_rss_tbl()
A recent commit has modified the code in __bnxt_reserve_rings() to
set the default RSS indirection table to default only when the number
of RX rings is changing. While this works for newer firmware that
requires RX ring reservations, it causes the regression on older
firmware not requiring RX ring resrvations (BNXT_NEW_RM() returns
false).
With older firmware, RX ring reservations are not required and so
hw_resc->resv_rx_rings is not always set to the proper value. The
comparison:
if (old_rx_rings != bp->hw_resc.resv_rx_rings)
in __bnxt_reserve_rings() may be false even when the RX rings are
changing. This will cause __bnxt_reserve_rings() to skip setting
the default RSS indirection table to default to match the current
number of RX rings. This may later cause bnxt_fill_hw_rss_tbl() to
use an out-of-range index.
We already have bnxt_check_rss_tbl_no_rmgr() to handle exactly this
scenario. We just need to move it up in bnxt_need_reserve_rings()
to be called unconditionally when using older firmware. Without the
fix, if the TX rings are changing, we'll skip the
bnxt_check_rss_tbl_no_rmgr() call and __bnxt_reserve_rings() may also
skip the bnxt_set_dflt_rss_indir_tbl() call for the reason explained
in the last paragraph. Without setting the default RSS indirection
table to default, it causes the regression:
BUG: KASAN: slab-out-of-bounds in __bnxt_hwrm_vnic_set_rss+0xb79/0xe40
Read of size 2 at addr ffff8881c5809618 by task ethtool/31525
Call Trace:
__bnxt_hwrm_vnic_set_rss+0xb79/0xe40
bnxt_hwrm_vnic_rss_cfg_p5+0xf7/0x460
__bnxt_setup_vnic_p5+0x12e/0x270
__bnxt_open_nic+0x2262/0x2f30
bnxt_open_nic+0x5d/0xf0
ethnl_set_channels+0x5d4/0xb30
ethnl_default_set_doit+0x2f1/0x620
Security readout for executives and security teams
Plain-English summary
CVE-2024-44933 is a Linux kernel bnxt_en network driver bug. Under certain older firmware behavior, changing network ring settings can leave the RSS table inconsistent and cause an out-of-bounds kernel memory read. The public sources show a kernel fix, but no CVSS score or active exploitation evidence.
Executive priority
Treat this as a targeted kernel driver maintenance issue, not an internet-wide emergency based on current evidence. Prioritize patching infrastructure that uses bnxt_en-supported Broadcom network adapters, especially where administrators frequently change NIC channel settings.
Technical view
The regression occurs when older firmware does not require RX ring reservations. __bnxt_reserve_rings() can skip resetting the RSS indirection table even when RX rings change, so bnxt_fill_hw_rss_tbl()/RSS setup may access an out-of-range index. The reported failure is a KASAN slab-out-of-bounds read during ethtool channel handling.
Likely exposure
Exposure appears limited to Linux systems using the bnxt_en driver, older affected firmware behavior, and affected kernel code paths. The source bundle does not prove broad exposure across all Linux hosts or all Broadcom adapters.
Exploitation context
The source bundle shows a regression triggered through network channel/RSS reconfiguration and a KASAN crash trace. It does not cite public exploitation, weaponized proof-of-concept activity, or KEV listing. KEV is false.
Researcher notes
Evidence is strongest for a kernel memory-safety regression in bnxt_en RSS table handling. Severity, CVSS, CWE mapping, and exploitability are not provided in the bundle. Avoid assuming privilege impact beyond the documented out-of-bounds read and crash trace.
Mitigation direction
Apply a Linux kernel or distro update containing the listed stable fixes.
Confirm vendor or distribution advisories for backported CVE-2024-44933 fixes.
Prioritize systems using the bnxt_en driver with Broadcom Ethernet hardware.
Limit nonessential channel or ring reconfiguration until patched, where operationally feasible.
Validation and detection
Inventory Linux hosts where the bnxt_en driver is present or loaded.
Check kernel package changelogs for CVE-2024-44933 or the referenced stable commits.
Identify hosts with Broadcom Ethernet adapters and older firmware behavior.
Validate updated kernels in staging before production rollout.
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Potential ATT&CK relevance
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
cve · low confidence lookup
CVE-2024-44933 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.