{"id":"CVE-2026-23368","title":"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[ 1…","summary":"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[ 1…","severity":"medium","cvss":5.5,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","cwe":["CWE-667"],"vendor":"linux","product":"linux_kernel","affected":["linux_kernel >= 4.16.1, < 5.10.253","linux_kernel >= 5.11, < 5.15.203","linux_kernel >= 5.16, < 6.1.167","linux_kernel >= 6.2, < 6.6.130","linux_kernel >= 6.7, < 6.12.78","linux_kernel >= 6.13, < 6.18.17","linux_kernel >= 6.19, < 6.19.7","linux_kernel = 4.16","linux_kernel = 7.0"],"patched":["linux_kernel 6.19.7"],"published":"2026-03-25","updated":"2026-10-15","sourceUpdated":"2026-10-15T02:18:52.607","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-23368","references":[{"url":"https://git.kernel.org/stable/c/241cd64cf2e32b28ead151b1795cd8fef2b6e482","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/2764dcb3c35de4410f642afc62cf979727470575","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/2b01518eabace18f7ec8b4cafd52082303080dca","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/305afdd02ff3e694c165457793104710ec0728e5","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/c33523b8fd2d4c504ada18cd93f511f2a8f84217","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/c6ffc2d2338d325e1edd0c702e3ee623aa5fdc6a","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/c8dbdc6e380e7e96a51706db3e4b7870d8a9402d","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/cde2d0b5ab5d03b5b6f17d4f654d8b30ccf36757","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-019113.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-082556.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-457936.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-784472.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"}],"tags":["nvd","cve.org"],"epss":0.00103,"epssPercentile":0.00979,"ingestedAt":"2026-09-08T15:33:26.992Z","slug":"CVE-2026-23368","body":"## Overview\n\nIn 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.\n\n## Affected\n\n- `linux_kernel >= 4.16.1, < 5.10.253`\n- `linux_kernel >= 5.11, < 5.15.203`\n- `linux_kernel >= 5.16, < 6.1.167`\n- `linux_kernel >= 6.2, < 6.6.130`\n- `linux_kernel >= 6.7, < 6.12.78`\n- `linux_kernel >= 6.13, < 6.18.17`\n- `linux_kernel >= 6.19, < 6.19.7`\n- `linux_kernel = 4.16`\n- `linux_kernel = 7.0`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `linux_kernel 6.19.7`","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":30.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":221669,"id":"CVE-2026-23368","ts":1792035313889,"field":"cvss","old":null,"new":"5.5"},{"seq":221668,"id":"CVE-2026-23368","ts":1792035313889,"field":"severity","old":"none","new":"medium"}]}