cbcvebase.
CVE-2025-39901
published 2025-10-01

CVE-2025-39901: In the Linux kernel, the following vulnerability has been resolved: i40e: remove read access to debugfs files The 'command' and 'netdev_ops' debugfs files are…

PriorityP336high7.1CVSS 3.1
AVLACLPRLUINSUCHINAH
EPSS
0.14%
3.9th percentile
In the Linux kernel, the following vulnerability has been resolved: i40e: remove read access to debugfs files The 'command' and 'netdev_ops' debugfs files are a legacy debugging interface supported by the i40e driver since its early days by commit 02e9c290814c ("i40e: debugfs interface"). Both of these debugfs files provide a read handler which is mostly useless, and which is implemented with questionable logic. They both use a static 256 byte buffer which is initialized to the empty string. In the case of the 'command' file this buffer is literally never used and simply wastes space. In the case of the 'netdev_ops' file, the last command written is saved here. On read, the files contents are presented as the name of the device followed by a colon and then the contents of their respective static buffer. For 'command' this will always be ": ". For 'netdev_ops', this will be ": ". But note the buffer is shared between all devices operated by this module. At best, it is mostly meaningless information, and at worse it could be accessed simultaneously as there doesn't appear to be any locking mechanism. We have also recently received multiple reports for both read functions about their use of snprintf and potential overflow that could result in reading arbitrary kernel memory. For the 'command' file, this is definitely impossible, since the static buffer is always zero and never written to. For the 'netdev_ops' file, it does appear to be possible, if the user carefully crafts the command input, it will be copied into the buffer, which could be large enough to cause snprintf to truncate, which then causes the copy_to_user to read beyond the length of the buffer allocated by kzalloc. A minimal fix would be to replace snprintf() with scnprintf() which would cap the return to the number of bytes written, preventing an overflow. A more involved fix would be to drop the mostly useless static buffers, saving 512 bytes and modifying the read functions to stop needing those

Affected

28 ranges· showing 25
VendorProductVersion rangeFixed in
debianlinux< linux 6.16.6-1 (forky)linux 6.16.6-1 (forky)
linuxlinux
linuxlinux>= 02e9c290814cc143ceccecb14eac3e7a05da745e < ef40d9411469306e524e7887c51b709377e6ef65ef40d9411469306e524e7887c51b709377e6ef65
linuxlinux>= 02e9c290814cc143ceccecb14eac3e7a05da745e < 70d3dad7d5ad077965d7a63eed1942b7ba49bfb470d3dad7d5ad077965d7a63eed1942b7ba49bfb4
linuxlinux>= 02e9c290814cc143ceccecb14eac3e7a05da745e < 7d190963b80f4cd99d7008615600aa7cc993c6ba7d190963b80f4cd99d7008615600aa7cc993c6ba
linuxlinux>= 02e9c290814cc143ceccecb14eac3e7a05da745e < 9fcdb1c3c4ba134434694c001dbff343f1ffa3199fcdb1c3c4ba134434694c001dbff343f1ffa319
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel>= 0 < 6.12.48-16.12.48-1
linuxlinux_kernel>= 0 < 6.16.6-16.16.6-1
linuxlinux_kernel>= 0 < 6.8.0-106.1066.8.0-106.106
linuxlinux_kernel>= 3.12 < 6.12.466.12.46
linuxlinux_kernel>= 6.13 < 6.16.66.16.6
msrcazl3_kernel_6.6.104.2-4_on_azure_linux_3.0
msrcazl3_kernel_6.6.112.1-2_on_azure_linux_3.0
msrcazl3_kernel_6.6.117.1-1_on_azure_linux_3.0
msrcazl3_kernel_6.6.119.3-1_on_azure_linux_3.0
msrcazl3_kernel_6.6.119.3-3_on_azure_linux_3.0
msrcazl3_kernel_6.6.121.1-1_on_azure_linux_3.0
msrcazl3_kernel_6.6.126.1-1_on_azure_linux_3.0
msrcazl3_kernel_6.6.130.1-3_on_azure_linux_3.0
msrcazl3_kernel_6.6.96.2-2_on_azure_linux_3.0
msrccbl2_kernel_5.15.186.1-1_on_cbl_mariner_2.0

CVSS provenance

nvdv3.17.1HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
osv7.1HIGH
vendor_ubuntu7.8HIGH
vendor_debian7.1HIGH
vendor_msrc7.1HIGH
vendor_redhat7.1HIGH
Stop checking back — get the weekly exploitation signal.

Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.