CVE-2026-43465
published 2026-05-08CVE-2026-43465: In the Linux kernel, the following vulnerability has been resolved: net/mlx5e: RX, Fix XDP multi-buf frag counting for striding RQ XDP multi-buf programs can…
PriorityP353critical9.8CVSS 3.1
AVNACLPRNUINSUCHIHAH
EPSS
0.41%
34.0th percentile
In the Linux kernel, the following vulnerability has been resolved:
net/mlx5e: RX, Fix XDP multi-buf frag counting for striding RQ
XDP multi-buf programs can modify the layout of the XDP buffer when the
program calls bpf_xdp_pull_data() or bpf_xdp_adjust_tail(). The
referenced commit in the fixes tag corrected the assumption in the mlx5
driver that the XDP buffer layout doesn't change during a program
execution. However, this fix introduced another issue: the dropped
fragments still need to be counted on the driver side to avoid page
fragment reference counting issues.
The issue was discovered by the drivers/net/xdp.py selftest,
more specifically the test_xdp_native_tx_mb:
- The mlx5 driver allocates a page_pool page and initializes it with
a frag counter of 64 (pp_ref_count=64) and the internal frag counter
to 0.
- The test sends one packet with no payload.
- On RX (mlx5e_skb_from_cqe_mpwrq_nonlinear()), mlx5 configures the XDP
buffer with the packet data starting in the first fragment which is the
page mentioned above.
- The XDP program runs and calls bpf_xdp_pull_data() which moves the
header into the linear part of the XDP buffer. As the packet doesn't
contain more data, the program drops the tail fragment since it no
longer contains any payload (pp_ref_count=63).
- mlx5 device skips counting this fragment. Internal frag counter
remains 0.
- mlx5 releases all 64 fragments of the page but page pp_ref_count is
63 => negative reference counting error.
Resulting splat during the test:
WARNING: CPU: 0 PID: 188225 at ./include/net/page_pool/helpers.h:297 mlx5e_page_release_fragmented.isra.0+0xbd/0xe0 [mlx5_core]
Modules linked in: [...]
CPU: 0 UID: 0 PID: 188225 Comm: ip Not tainted 6.18.0-rc7_for_upstream_min_debug_2025_12_08_11_44 #1 NONE
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
RIP: 0010:mlx5e_page_release_fragmented.isra.0+0xbd/0xe0 [mlx5_core]
[...]
Call Trace:
mlx5e_free_rx_mpwqe+0x20a
Affected
18 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| linux | linux | — | — |
| linux | linux | — | — |
| linux | linux | — | — |
| linux | linux | — | — |
| linux | linux | >= 6.12.56 < 6.13 | 6.13 |
| linux | linux | >= 6.17.6 < 6.18 | 6.18 |
| linux | linux | >= 6.6.115 < 6.7 | 6.7 |
| linux | linux | >= 87bcef158ac1faca1bd7e0104588e8e2956d10be < 7d7342a18fadcdb70a63b3c930dc63528ce51832 | 7d7342a18fadcdb70a63b3c930dc63528ce51832 |
| linux | linux | >= 87bcef158ac1faca1bd7e0104588e8e2956d10be < 043bd62f748bc9fd98154037aa598cffbd3c667c | 043bd62f748bc9fd98154037aa598cffbd3c667c |
| linux | linux | >= 87bcef158ac1faca1bd7e0104588e8e2956d10be < db25c42c2e1f9c0d136420fff5e5700f7e771a6f | db25c42c2e1f9c0d136420fff5e5700f7e771a6f |
| linux | linux_kernel | — | — |
| linux | linux_kernel | — | — |
| linux | linux_kernel | — | — |
| linux | linux_kernel | >= 6.12.56 < 6.13 | 6.13 |
| linux | linux_kernel | >= 6.17.6 < 6.18 | 6.18 |
| linux | linux_kernel | >= 6.18.1 < 6.18.19 | 6.18.19 |
| linux | linux_kernel | >= 6.19 < 6.19.9 | 6.19.9 |
| linux | linux_kernel | >= 6.6.115 < 6.7 | 6.7 |
CVSS provenance
nvdv3.19.8CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
vendor_redhat7.0MEDIUM
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Red Hat
kernel: net/mlx5e: RX, Fix XDP multi-buf frag counting for striding RQ
vendor_redhat·2026-05-08·CVSS 7.0
CVE-2026-43465 [MEDIUM] CWE-911 kernel: net/mlx5e: RX, Fix XDP multi-buf frag counting for striding RQ
kernel: net/mlx5e: RX, Fix XDP multi-buf frag counting for striding RQ
A flaw was found in the Linux kernel's mlx5e driver. This vulnerability arises from incorrect fragment counting when XDP (eXpress Data Path) multi-buffer programs modify the XDP buffer layout. This issue could allow a local attacker or a specially crafted network packet to trigger a negative reference counting error, leading to system instability or a denial of service.
Package: kernel (Red Hat Enterprise Linux 10) - Affected
Package: kernel (Red Hat Enterprise Linux 6) - Out of support scope
Package: kernel (Red Hat Enterprise Linux 7) - Not affected
Package: kernel-rt (Red Hat Enterprise Linux 7) - Not affected
Package: kernel (Red Hat Enterprise Linux 8) - Not affected
Package: kernel-rt (Red Hat Enterprise Li
VulDB
Linux Kernel up to 6.18.18/6.19.8 mlx5e bpf_xdp_pull_data privilege escalation
vuldb·2026-05-21·CVSS 9.8
CVE-2026-43465 [CRITICAL] Linux Kernel up to 6.18.18/6.19.8 mlx5e bpf_xdp_pull_data privilege escalation
A vulnerability, which was classified as problematic, was found in Linux Kernel up to 6.18.18/6.19.8. Impacted is the function bpf_xdp_pull_data of the component mlx5e. Executing a manipulation can lead to privilege escalation.
The identification of this vulnerability is CVE-2026-43465. The attack needs to be done within the local network. There is no exploit available.
You should upgrade the affected component.
GHSA
GHSA-wm82-xv2w-22mm: In the Linux kernel, the following vulnerability has been resolved:
net/mlx5e: RX, Fix XDP multi-buf frag counting for striding RQ
XDP multi-buf pro
ghsa_unreviewed·2026-05-08
CVE-2026-43465 GHSA-wm82-xv2w-22mm: In the Linux kernel, the following vulnerability has been resolved:
net/mlx5e: RX, Fix XDP multi-buf frag counting for striding RQ
XDP multi-buf pro
In the Linux kernel, the following vulnerability has been resolved:
net/mlx5e: RX, Fix XDP multi-buf frag counting for striding RQ
XDP multi-buf programs can modify the layout of the XDP buffer when the
program calls bpf_xdp_pull_data() or bpf_xdp_adjust_tail(). The
referenced commit in the fixes tag corrected the assumption in the mlx5
driver that the XDP buffer layout doesn't change during a program
execution. However, this fix introduced another issue: the dropped
fragments still need to be counted on the driver side to avoid page
fragment reference counting issues.
The issue was discovered by the drivers/net/xdp.py selftest,
more specifically the test_xdp_native_tx_mb:
- The mlx5 driver allocates a page_pool page and initializes it with
a frag counter of 64 (pp_ref_count=64) and the
No detection rules found.
No public exploits indexed.
2026-05-08
Published