{"id":"CVE-2026-98563","state":"PUBLISHED","title":"net: phylink: record the PHY only once bringup cannot fail","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: phylink: record the PHY only once bringup cannot fail\n\nphylink_bringup_phy() stores the PHY in pl->phydev before its last\nfallible step: on a MAC whose phylink ops implement LPI,\nphy_eee_rx_clock_stop() can fail with a real MDIO error. The callers\nunwind with phy_detach(), which knows nothing about pl->phydev, so a\npointer to a PHY that is no longer attached outlives the failed\nconnect.\n\nWhat that costs depends on how the caller got here.\nphylink_connect_phy() goes through phylink_attach_phy(), which refuses\nto attach while pl->phydev is set, turning a transient MDIO error into\na permanent -EBUSY. The SFP path is worse than that: sfp_sm_probe_phy()\nanswers the failure with phy_device_remove() and phy_device_free(), and\nit assigns sfp->mod_phy only past that error return, so nothing clears\npl->phydev and it is left pointing at a freed phy_device that\nphylink_resolve() and the ethtool helpers go on reading.\nphylink_fwnode_phy_connect() has no such check, so a later connect\noverwrites the stale pointer and hides the problem. A disconnect does\nnot: phylink_disconnect_phy() hands that pointer to phy_disconnect(),\nand the second phy_detach() on the same PHY drops references the first\none already released.\n\nFound while making a DSA port survive a PHY whose driver arrives after\nthe switch probes: keeping the port across a failed connect and\nretrying is what makes this window reachable.\n\nPublish the pointer after the last call that can fail instead of\nunwinding it afterwards. Nothing between the two points reads\npl->phydev, and the registration that follows cannot fail:\nphy_request_interrupt() falls back to polling on its own. The PHY-side\nstate keeps the order it had, so no MDIO operation moves relative to\nanother.","publishedAt":"2026-10-18T15:18:30.158Z","updatedAt":"2026-10-19T09:21:47.748Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"03abf2a7c65451e663b078b0ed1bfa648cd9380f","status":"affected","lessThan":"4e7a4af364c2048bafb213bf0ef4a89dcbe1bfd4","versionType":"git"},{"version":"03abf2a7c65451e663b078b0ed1bfa648cd9380f","status":"affected","lessThan":"671a68654a9d319d7f0d53a6321db3d9b391bdef","versionType":"git"},{"version":"03abf2a7c65451e663b078b0ed1bfa648cd9380f","status":"affected","lessThan":"a940003f44e7e441c228151dd212642152700ec8","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/phy/phylink.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.14","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.14","versionType":"semver"},{"version":"6.18.55","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.9","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/phy/phylink.c"]}],"references":["https://git.kernel.org/stable/c/4e7a4af364c2048bafb213bf0ef4a89dcbe1bfd4","https://git.kernel.org/stable/c/671a68654a9d319d7f0d53a6321db3d9b391bdef","https://git.kernel.org/stable/c/a940003f44e7e441c228151dd212642152700ec8"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:43.249Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/98xxx/CVE-2026-98563.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-98563","state":"PUBLISHED","datePublished":"2026-10-18T15:18:30.158Z","dateUpdated":"2026-10-19T09:21:47.748Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-25T10:25:14.357Z"},"containers":{"cna":{"title":"net: phylink: record the PHY only once bringup cannot fail","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: phylink: record the PHY only once bringup cannot fail\n\nphylink_bringup_phy() stores the PHY in pl->phydev before its last\nfallible step: on a MAC whose phylink ops implement LPI,\nphy_eee_rx_clock_stop() can fail with a real MDIO error. The callers\nunwind with phy_detach(), which knows nothing about pl->phydev, so a\npointer to a PHY that is no longer attached outlives the failed\nconnect.\n\nWhat that costs depends on how the caller got here.\nphylink_connect_phy() goes through phylink_attach_phy(), which refuses\nto attach while pl->phydev is set, turning a transient MDIO error into\na permanent -EBUSY. The SFP path is worse than that: sfp_sm_probe_phy()\nanswers the failure with phy_device_remove() and phy_device_free(), and\nit assigns sfp->mod_phy only past that error return, so nothing clears\npl->phydev and it is left pointing at a freed phy_device that\nphylink_resolve() and the ethtool helpers go on reading.\nphylink_fwnode_phy_connect() has no such check, so a later connect\noverwrites the stale pointer and hides the problem. A disconnect does\nnot: phylink_disconnect_phy() hands that pointer to phy_disconnect(),\nand the second phy_detach() on the same PHY drops references the first\none already released.\n\nFound while making a DSA port survive a PHY whose driver arrives after\nthe switch probes: keeping the port across a failed connect and\nretrying is what makes this window reachable.\n\nPublish the pointer after the last call that can fail instead of\nunwinding it afterwards. Nothing between the two points reads\npl->phydev, and the registration that follows cannot fail:\nphy_request_interrupt() falls back to polling on its own. The PHY-side\nstate keeps the order it had, so no MDIO operation moves relative to\nanother."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"03abf2a7c65451e663b078b0ed1bfa648cd9380f","status":"affected","lessThan":"4e7a4af364c2048bafb213bf0ef4a89dcbe1bfd4","versionType":"git"},{"version":"03abf2a7c65451e663b078b0ed1bfa648cd9380f","status":"affected","lessThan":"671a68654a9d319d7f0d53a6321db3d9b391bdef","versionType":"git"},{"version":"03abf2a7c65451e663b078b0ed1bfa648cd9380f","status":"affected","lessThan":"a940003f44e7e441c228151dd212642152700ec8","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/phy/phylink.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.14","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.14","versionType":"semver"},{"version":"6.18.55","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.9","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/phy/phylink.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/4e7a4af364c2048bafb213bf0ef4a89dcbe1bfd4"},{"url":"https://git.kernel.org/stable/c/671a68654a9d319d7f0d53a6321db3d9b391bdef"},{"url":"https://git.kernel.org/stable/c/a940003f44e7e441c228151dd212642152700ec8"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-19T09:21:47.748Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.14","versionEndExcluding":"6.18.55"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.14","versionEndExcluding":"7.2.9"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.14","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}