Critical severity · published Dec 16, 2025
CVE-2025-40350
net/mlx5e: RX, Fix generating skb from non-linear xdp_buff for striding RQ
9.8
CVSS
0.5%
EPSS
No
On KEV
Description
In the Linux kernel, the following vulnerability has been resolved:
net/mlx5e: RX, Fix generating skb from non-linear xdp_buff for striding RQ
XDP programs can change the layout of an xdp_buff through
bpf_xdp_adjust_tail() and bpf_xdp_adjust_head(). Therefore, the driver
cannot assume the size of the linear data area nor fragments. Fix the
bug in mlx5 by generating skb according to xdp_buff after XDP programs
run.
Currently, when handling multi-buf XDP, the mlx5 driver assumes the
layout of an xdp_buff to be unchanged. That is, the linear data area
continues to be empty and fragments remain the same. This may cause
the driver to generate erroneous skb or triggering a kernel
warning. When an XDP program added linear data through
bpf_xdp_adjust_head(), the linear data will be ignored as
mlx5e_build_linear_skb() builds an skb without linear data and then
pull data from fragments to fill the linear data area. When an XDP
program has shrunk the non-linear data through bpf_xdp_adjust_tail(),
the delta passed to __pskb_pull_tail() may exceed the actual nonlinear
data size and trigger the BUG_ON in it.
To fix the issue, first record the original number of fragments. If the
number of fragments changes after the XDP program runs, rewind the end
fragment pointer by the difference and recalculate the truesize. Then,
build the skb with the linear data area matching the xdp_buff. Finally,
only pull data in if there is non-linear data and fill the linear part
up to 256 bytes.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.5% · higher than 46% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
LI
Linux · Linux
f52ac7028bec22e925c8fece4f21641eb13b4d6f before 8b051d7f530e8a5237da242fbeafef02fec6b813; f52ac7028bec22e925c8fece4f21641eb13b4d6f before cb9edd583e23979ee546981be963ad5f217e8b18; f52ac7028bec22e925c8fece4f21641eb13b4d6f before f2557d7fa38e9475b38588f5c124476091480f53; f52ac7028bec22e925c8fece4f21641eb13b4d6f before 87bcef158ac1faca1bd7e0104588e8e2956d10be; 6.4 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-40350
CVE.org
https://www.cve.org/CVERecord?id=CVE-2025-40350
git.kernel.org
https://git.kernel.org/stable/c/87bcef158ac1faca1bd7e0104588e8e2956d10be
git.kernel.org
https://git.kernel.org/stable/c/8b051d7f530e8a5237da242fbeafef02fec6b813
git.kernel.org
https://git.kernel.org/stable/c/cb9edd583e23979ee546981be963ad5f217e8b18
git.kernel.org
https://git.kernel.org/stable/c/f2557d7fa38e9475b38588f5c124476091480f53
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