VulnerabilityPublished 25 Mar 2026Updated 5 Nov 2026

CVE-2026-23368: Linux kernel · net: phy: register phy led_triggers during probe to avoid AB-BA deadlock

Affects Linux kernelSource CVE Database V5

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Not known to be exploited · fixed in cde2d0b5ab5d03b5b6f17d4f654d8b30ccf36757 : update Linux kernel when convenient.

Data as of 5 Nov 2026, 21:49 UTC

Severity

Unrated

Rated by Threat Radar · No CVSS score from NVD or the CNA

Thin evidence

One scorer or none

Exploitation: No evidence of active exploitation and no public proof of concept
Automatable: Attackers cannot reliably automate steps 1–4 of the kill chain
Technical impact: Limited control over the software or limited information exposure

CISA SSVC assessment, 2026-11-05.

Patch

Available – fixed in cde2d0b5ab5d03b5b6f17d4f654d8b30ccf36757, c33523b8fd2d4c504ada18cd93f511f2a8f84217, c8dbdc6e380e7e96a51706db3e4b7870d8a9402d +5

Exploitation evidence

Disclosed: evidence found.
CVE published 25 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 5 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 06f502f57d0d7728f9fa0f157ec5e4111ddb98f6, < cde2d0b5ab5d03b5b6f17d4f654d8b30ccf36757	Fixed in cde2d0b5ab5d03b5b6f17d4f654d8b30ccf36757
LinuxLinux	Affected ≥ 06f502f57d0d7728f9fa0f157ec5e4111ddb98f6, < c33523b8fd2d4c504ada18cd93f511f2a8f84217	Fixed in c33523b8fd2d4c504ada18cd93f511f2a8f84217
LinuxLinux	Affected ≥ 06f502f57d0d7728f9fa0f157ec5e4111ddb98f6, < c8dbdc6e380e7e96a51706db3e4b7870d8a9402d	Fixed in c8dbdc6e380e7e96a51706db3e4b7870d8a9402d
LinuxLinux	Affected ≥ 06f502f57d0d7728f9fa0f157ec5e4111ddb98f6, < c6ffc2d2338d325e1edd0c702e3ee623aa5fdc6a	Fixed in c6ffc2d2338d325e1edd0c702e3ee623aa5fdc6a
LinuxLinux	Affected ≥ 06f502f57d0d7728f9fa0f157ec5e4111ddb98f6, < 2764dcb3c35de4410f642afc62cf979727470575	Fixed in 2764dcb3c35de4410f642afc62cf979727470575
LinuxLinux	Affected ≥ 06f502f57d0d7728f9fa0f157ec5e4111ddb98f6, < 305afdd02ff3e694c165457793104710ec0728e5	Fixed in 305afdd02ff3e694c165457793104710ec0728e5

Description

In the Linux kernel, the following vulnerability has been resolved: net: phy: register phy led_triggers during probe to avoid AB-BA deadlock There is an AB-BA deadlock when both LEDS_TRIGGER_NETDEV and LED_TRIGGER_PHY are enabled: [ 1362.049207] [<8054e4b8>] led_trigger_register+0x5c/0x1fc <-- Trying to get lock "triggers_list_lock" via down_write(&triggers_list_lock); [ 1362.054536] [<80662830>] phy_led_triggers_register+0xd0/0x234 [ 1362.060329] [<8065e200>] phy_attach_direct+0x33c/0x40c [ 1362.065489] [<80651fc4>] phylink_fwnode_phy_connect+0x15c/0x23c [ 1362.071480] [<8066ee18>] mtk_open+0x7c/0xba0 [ 1362.075849] [<806d714c>] __dev_open+0x280/0x2b0 [ 1362.080384] [<806d7668>] __dev_change_flags+0x244/0x24c [ 1362.085598] [<806d7698>] dev_change_flags+0x28/0x78 [ 1362.090528] [<807150e4>] dev_ioctl+0x4c0/0x654 <-- Hold lock "rtnl_mutex" by calling rtnl_lock(); [ 1362.094985] [<80694360>] sock_ioctl+0x2f4/0x4e0 [ 1362.099567] [<802e9c4c>] sys_ioctl+0x32c/0xd8c [ 1362.104022] [<80014504>] syscall_common+0x34/0x58 Here LED_TRIGGER_PHY is registering LED triggers during phy_attach while holding RTNL and then taking triggers_list_lock. [ 1362.191101] [<806c2640>] register_netdevice_notifier+0x60/0x168 <-- Trying to get lock "rtnl_mutex" via rtnl_lock(); [ 1362.197073] [<805504ac>] netdev_trig_activate+0x194/0x1e4 [ 1362.202490] [<8054e28c>] led_trigger_set+0x1d4/0x360 <-- Hold lock "triggers_list_lock" by down_read(&triggers_list_lock); [ 1362.207511] [<8054eb38>] led_trigger_write+0xd8/0x14c [ 1362.212566] [<80381d98>] sysfs_kf_bin_write+0x80/0xbc [ 1362.217688] [<8037fcd8>] kernfs_fop_write_iter+0x17c/0x28c [ 1362.223174] [<802cbd70>] vfs_write+0x21c/0x3c4 [ 1362.227712] [<802cc0c4>] ksys_write+0x78/0x12c [ 1362.232164] [<80014504>] syscall_common+0x34/0x58 Here LEDS_TRIGGER_NETDEV is being enabled on an LED. It first takes triggers_list_lock and then RTNL. A classical AB-BA deadlock. phy_led_triggers_registers() does not require the RTNL, it does not make any calls into the network stack which require protection. There is also no requirement the PHY has been attached to a MAC, the triggers only make use of phydev state. This allows the call to phy_led_triggers_registers() to be placed elsewhere. PHY probe() and release() don't hold RTNL, so solving the AB-BA deadlock.

References

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