Vulnerability Details CVE-2026-43464
In the Linux kernel, the following vulnerability has been resolved:
net/mlx5e: RX, Fix XDP multi-buf frag counting for legacy 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.
Such issue can be observed with the
test_xdp_native_adjst_tail_shrnk_data selftest when using a payload of
3600 and shrinking by 256 bytes (an upcoming selftest patch): the last
fragment gets released by the XDP code but doesn't get tracked by the
driver. This results in a negative pp_ref_count during page release and
the following splat:
WARNING: include/net/page_pool/helpers.h:297 at mlx5e_page_release_fragmented.isra.0+0x4a/0x50 [mlx5_core], CPU#12: ip/3137
Modules linked in: [...]
CPU: 12 UID: 0 PID: 3137 Comm: ip Not tainted 6.19.0-rc3+ #12 NONE
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
RIP: 0010:mlx5e_page_release_fragmented.isra.0+0x4a/0x50 [mlx5_core]
[...]
Call Trace:
<TASK>
mlx5e_dealloc_rx_wqe+0xcb/0x1a0 [mlx5_core]
mlx5e_free_rx_descs+0x7f/0x110 [mlx5_core]
mlx5e_close_rq+0x50/0x60 [mlx5_core]
mlx5e_close_queues+0x36/0x2c0 [mlx5_core]
mlx5e_close_channel+0x1c/0x50 [mlx5_core]
mlx5e_close_channels+0x45/0x80 [mlx5_core]
mlx5e_safe_switch_params+0x1a5/0x230 [mlx5_core]
mlx5e_change_mtu+0xf3/0x2f0 [mlx5_core]
netif_set_mtu_ext+0xf1/0x230
do_setlink.isra.0+0x219/0x1180
rtnl_newlink+0x79f/0xb60
rtnetlink_rcv_msg+0x213/0x3a0
netlink_rcv_skb+0x48/0xf0
netlink_unicast+0x24a/0x350
netlink_sendmsg+0x1ee/0x410
__sock_sendmsg+0x38/0x60
____sys_sendmsg+0x232/0x280
___sys_sendmsg+0x78/0xb0
__sys_sendmsg+0x5f/0xb0
[...]
do_syscall_64+0x57/0xc50
This patch fixes the issue by doing page frag counting on all the
original XDP buffer fragments for all relevant XDP actions (XDP_TX ,
XDP_REDIRECT and XDP_PASS). This is basically reverting to the original
counting before the commit in the fixes tag.
As frag_page is still pointing to the original tail, the nr_frags
parameter to xdp_update_skb_frags_info() needs to be calculated
in a different way to reflect the new nr_frags.
Exploit prediction scoring system (EPSS) score
EPSS Score 0.001
EPSS Ranking 22.6%
CVSS Severity
CVSS v3 Score 7.5
Products affected by CVE-2026-43464
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cpe:2.3:o:linux:linux_kernel:6.12.56
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cpe:2.3:o:linux:linux_kernel:6.12.57
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cpe:2.3:o:linux:linux_kernel:6.12.58
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cpe:2.3:o:linux:linux_kernel:6.12.59
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cpe:2.3:o:linux:linux_kernel:6.12.60
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cpe:2.3:o:linux:linux_kernel:6.12.61
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cpe:2.3:o:linux:linux_kernel:6.12.62
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cpe:2.3:o:linux:linux_kernel:6.12.63
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cpe:2.3:o:linux:linux_kernel:6.12.64
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cpe:2.3:o:linux:linux_kernel:6.12.65
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cpe:2.3:o:linux:linux_kernel:6.12.66
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cpe:2.3:o:linux:linux_kernel:6.12.67
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cpe:2.3:o:linux:linux_kernel:6.12.68
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cpe:2.3:o:linux:linux_kernel:6.12.69
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cpe:2.3:o:linux:linux_kernel:6.12.70
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cpe:2.3:o:linux:linux_kernel:6.12.72
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cpe:2.3:o:linux:linux_kernel:6.12.74
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cpe:2.3:o:linux:linux_kernel:6.12.75
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cpe:2.3:o:linux:linux_kernel:6.12.77
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cpe:2.3:o:linux:linux_kernel:6.12.78
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cpe:2.3:o:linux:linux_kernel:6.12.80
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cpe:2.3:o:linux:linux_kernel:6.12.81
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cpe:2.3:o:linux:linux_kernel:6.12.82
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cpe:2.3:o:linux:linux_kernel:6.12.83
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cpe:2.3:o:linux:linux_kernel:6.12.84
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cpe:2.3:o:linux:linux_kernel:6.12.85
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cpe:2.3:o:linux:linux_kernel:6.12.87
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cpe:2.3:o:linux:linux_kernel:6.17.10
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cpe:2.3:o:linux:linux_kernel:6.17.11
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cpe:2.3:o:linux:linux_kernel:6.17.12
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cpe:2.3:o:linux:linux_kernel:6.17.13
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cpe:2.3:o:linux:linux_kernel:6.17.6
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cpe:2.3:o:linux:linux_kernel:6.17.7
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cpe:2.3:o:linux:linux_kernel:6.17.8
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cpe:2.3:o:linux:linux_kernel:6.17.9
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cpe:2.3:o:linux:linux_kernel:6.18
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cpe:2.3:o:linux:linux_kernel:6.18.1
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cpe:2.3:o:linux:linux_kernel:6.18.10
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cpe:2.3:o:linux:linux_kernel:6.18.11
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cpe:2.3:o:linux:linux_kernel:6.18.13
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cpe:2.3:o:linux:linux_kernel:6.18.14
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cpe:2.3:o:linux:linux_kernel:6.18.16
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cpe:2.3:o:linux:linux_kernel:6.18.17
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cpe:2.3:o:linux:linux_kernel:6.18.18
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cpe:2.3:o:linux:linux_kernel:6.18.2
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cpe:2.3:o:linux:linux_kernel:6.18.3
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cpe:2.3:o:linux:linux_kernel:6.18.4
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cpe:2.3:o:linux:linux_kernel:6.18.5
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cpe:2.3:o:linux:linux_kernel:6.18.6
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cpe:2.3:o:linux:linux_kernel:6.18.7
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cpe:2.3:o:linux:linux_kernel:6.18.8
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cpe:2.3:o:linux:linux_kernel:6.18.9
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cpe:2.3:o:linux:linux_kernel:6.19
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cpe:2.3:o:linux:linux_kernel:6.19.1
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cpe:2.3:o:linux:linux_kernel:6.19.3
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cpe:2.3:o:linux:linux_kernel:6.19.4
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cpe:2.3:o:linux:linux_kernel:6.19.6
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cpe:2.3:o:linux:linux_kernel:6.19.7
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cpe:2.3:o:linux:linux_kernel:6.19.8
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cpe:2.3:o:linux:linux_kernel:6.6.115
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cpe:2.3:o:linux:linux_kernel:6.6.116
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cpe:2.3:o:linux:linux_kernel:6.6.117
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cpe:2.3:o:linux:linux_kernel:6.6.118
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cpe:2.3:o:linux:linux_kernel:6.6.119
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cpe:2.3:o:linux:linux_kernel:6.6.120
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cpe:2.3:o:linux:linux_kernel:6.6.121
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cpe:2.3:o:linux:linux_kernel:6.6.122
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cpe:2.3:o:linux:linux_kernel:6.6.123
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cpe:2.3:o:linux:linux_kernel:6.6.124
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cpe:2.3:o:linux:linux_kernel:6.6.125
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cpe:2.3:o:linux:linux_kernel:6.6.127
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cpe:2.3:o:linux:linux_kernel:6.6.128
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cpe:2.3:o:linux:linux_kernel:6.6.129
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cpe:2.3:o:linux:linux_kernel:6.6.130
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cpe:2.3:o:linux:linux_kernel:6.6.131
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cpe:2.3:o:linux:linux_kernel:6.6.134
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cpe:2.3:o:linux:linux_kernel:6.6.135
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cpe:2.3:o:linux:linux_kernel:6.6.136
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cpe:2.3:o:linux:linux_kernel:6.6.137
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cpe:2.3:o:linux:linux_kernel:6.6.138
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cpe:2.3:o:linux:linux_kernel:7.0