5.5

CVE-2026-23368: linux Improper Locking

CVSS: 5.5v3.1MediumModified
AliasesUBUNTU-CVE-2026-23368DEBIAN-CVE-2026-23368
Published 25-03-2026Last modified 15-10-2026
Open JSON

Vulnerability summary

CVE-2026-23368 is a medium (CVSS 5.5) Improper Locking vulnerability in linux. EPSS estimates a 0.10% chance of exploitation in the next 30 days, higher than 0.7% of scored vulnerabilities.

Overall risk
22/100
0100
Low · default modelHow is this calculated?
CVSS score
5.5/10
010
Medium · v3.1 (NVD)
EPSS score
0.10%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 31 · Related 29
MGASA-2026-0097MGASA-2026-0098SUSE-SU-2026:21834-1SUSE-SU-2026:2238-1USN-8567-1USN-8574-1

Timeline

  1. 25-03-2026
    PublishedVulnerability first disclosed.
  2. 15-10-2026
    Last modifiedVulnerability information updated.

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.

CVSS metrics

3 scores · 3 sources · 1 version

EPSS trend

Probability

0.10%

Chance of exploitation in the next 30 days

Percentile

1%

Versus all other CVEs

30-day change

0.00 pp

From 0.10% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.10%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Ubuntu153 products
  • linuxAll versions (No fix recorded) | < 5.15.0-186.196 | < 6.8.0-136.136
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-awsAll versions (No fix recorded) | < 5.15.0-1112.119 | < 6.8.0-1061.64
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Linux2 products
  • linux≥ 06f502f57d0d7728f9fa0f157ec5e4111ddb98f6, < 2b01518eabace18f7ec8b4cafd52082303080dca | ≥ 06f502f57d0d7728f9fa0f157ec5e4111ddb98f6, < 305afdd02ff3e694c165457793104710ec0728e5 | ≥ 06f502f57d0d7728f9fa0f157ec5e4111ddb98f6, < c6ffc2d2338d325e1edd0c702e3ee623aa5fdc6a | ≥ 06f502f57d0d7728f9fa0f157ec5e4111ddb98f6, < c33523b8fd2d4c504ada18cd93f511f2a8f84217 | ≥ 06f502f57d0d7728f9fa0f157ec5e4111ddb98f6, < 241cd64cf2e32b28ead151b1795cd8fef2b6e482 | ≥ 06f502f57d0d7728f9fa0f157ec5e4111ddb98f6, < 2764dcb3c35de4410f642afc62cf979727470575 | ≥ 06f502f57d0d7728f9fa0f157ec5e4111ddb98f6, < cde2d0b5ab5d03b5b6f17d4f654d8b30ccf36757 | ≥ 06f502f57d0d7728f9fa0f157ec5e4111ddb98f6, < c8dbdc6e380e7e96a51706db3e4b7870d8a9402d | 4.16
  • linux_kernel≥ 4.16.1, < 5.10.253 | ≥ 5.11, < 5.15.203 | ≥ 5.16, < 6.1.167 | ≥ 6.2, < 6.6.130 | ≥ 6.7, < 6.12.78 | ≥ 6.13, < 6.18.17 | ≥ 6.19, < 6.19.7 | 4.16 | 7.0:rc1 | 7.0:rc2 | 7.0:rc3 | 7.0:rc4 | 7.0:rc5 | 7.0:rc6 | 7.0:rc7
Debian1 product
  • linux< 6.1.170-1 | < 6.12.85-1 | < 6.19.8-1

3 vendors · 156 products

References

44 links
Show all 44 references