{"cve":"CVE-2026-23368","nvd":{"published":"2026-03-25T11:16:36.167","modified":"2026-10-15T02:18:52.607","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: phy: register phy led_triggers during probe to avoid AB-BA deadlock\n\nThere is an AB-BA deadlock when both LEDS_TRIGGER_NETDEV and\nLED_TRIGGER_PHY are enabled:\n\n[ 1362.049207] [<8054e4b8>] led_trigger_register+0x5c/0x1fc             <-- Trying to get lock \"triggers_list_lock\" via down_write(&triggers_list_lock);\n[ 1362.054536] [<80662830>] phy_led_triggers_register+0xd0/0x234\n[ 1362.060329] [<8065e200>] phy_attach_direct+0x33c/0x40c\n[ 1362.065489] [<80651fc4>] phylink_fwnode_phy_connect+0x15c/0x23c\n[ 1362.071480] [<8066ee18>] mtk_open+0x7c/0xba0\n[ 1362.075849] [<806d714c>] __dev_open+0x280/0x2b0\n[ 1362.080384] [<806d7668>] __dev_change_flags+0x244/0x24c\n[ 1362.085598] [<806d7698>] dev_change_flags+0x28/0x78\n[ 1362.090528] [<807150e4>] dev_ioctl+0x4c0/0x654                       <-- Hold lock \"rtnl_mutex\" by calling rtnl_lock();\n[ 1362.094985] [<80694360>] sock_ioctl+0x2f4/0x4e0\n[ 1362.099567] [<802e9c4c>] sys_ioctl+0x32c/0xd8c\n[ 1362.104022] [<80014504>] syscall_common+0x34/0x58\n\nHere LED_TRIGGER_PHY is registering LED triggers during phy_attach\nwhile holding RTNL and then taking triggers_list_lock.\n\n[ 1362.191101] [<806c2640>] register_netdevice_notifier+0x60/0x168      <-- Trying to get lock \"rtnl_mutex\" via rtnl_lock();\n[ 1362.197073] [<805504ac>] netdev_trig_activate+0x194/0x1e4\n[ 1362.202490] [<8054e28c>] led_trigger_set+0x1d4/0x360                 <-- Hold lock \"triggers_list_lock\" by down_read(&triggers_list_lock);\n[ 1362.207511] [<8054eb38>] led_trigger_write+0xd8/0x14c\n[ 1362.212566] [<80381d98>] sysfs_kf_bin_write+0x80/0xbc\n[ 1362.217688] [<8037fcd8>] kernfs_fop_write_iter+0x17c/0x28c\n[ 1362.223174] [<802cbd70>] vfs_write+0x21c/0x3c4\n[ 1362.227712] [<802cc0c4>] ksys_write+0x78/0x12c\n[ 1362.232164] [<80014504>] syscall_common+0x34/0x58\n\nHere LEDS_TRIGGER_NETDEV is being enabled on an LED. It first takes\ntriggers_list_lock and then RTNL. A classical AB-BA deadlock.\n\nphy_led_triggers_registers() does not require the RTNL, it does not\nmake any calls into the network stack which require protection. There\nis also no requirement the PHY has been attached to a MAC, the\ntriggers only make use of phydev state. This allows the call to\nphy_led_triggers_registers() to be placed elsewhere. PHY probe() and\nrelease() don't hold RTNL, so solving the AB-BA deadlock.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-667"],"references":["https://git.kernel.org/stable/c/241cd64cf2e32b28ead151b1795cd8fef2b6e482","https://git.kernel.org/stable/c/2764dcb3c35de4410f642afc62cf979727470575","https://git.kernel.org/stable/c/2b01518eabace18f7ec8b4cafd52082303080dca","https://git.kernel.org/stable/c/305afdd02ff3e694c165457793104710ec0728e5","https://git.kernel.org/stable/c/c33523b8fd2d4c504ada18cd93f511f2a8f84217"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:28:18.033120106+00:00"},"epss":{"cve":"CVE-2026-23368","score":0.00103,"percentile":0.00981,"date":"2026-10-26"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}