{"id":"CVE-2026-98173","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: fix use-after-free of iface in cifs_try_adding_channels()\n\ncifs_try_adding_channels() iterates ses->iface_list with\nlist_for_each_entry_safe_from(), which …","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: fix use-after-free of iface in cifs_try_adding_channels()\n\ncifs_try_adding_channels() iterates ses->iface_list with\nlist_for_each_entry_safe_from(), which …","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= aa45dadd34e44fcd6a9df4b395bee5b5633b4cec < c941f1ebfd26f683de81091473f3596a218abff0","Linux >= aa45dadd34e44fcd6a9df4b395bee5b5633b4cec < e99040e5e9c60441e6b4725e1a7b88c3106ae903","Linux >= aa45dadd34e44fcd6a9df4b395bee5b5633b4cec < ec36b38e65596950e6c29bed7dfc90b98707c19c","Linux >= aa45dadd34e44fcd6a9df4b395bee5b5633b4cec < d034e836eefd7ce75e588f7031cffbeec594f5ac","Linux 5.19"],"published":"2026-10-06","updated":"2026-10-06","sourceUpdated":"2026-10-06T09:17:59.060","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-98173","references":[{"url":"https://git.kernel.org/stable/c/c941f1ebfd26f683de81091473f3596a218abff0","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/d034e836eefd7ce75e588f7031cffbeec594f5ac","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/e99040e5e9c60441e6b4725e1a7b88c3106ae903","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/ec36b38e65596950e6c29bed7dfc90b98707c19c","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd","cve.org"],"ingestedAt":"2026-10-06T08:50:17.457Z","slug":"CVE-2026-98173","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: fix use-after-free of iface in cifs_try_adding_channels()\n\ncifs_try_adding_channels() iterates ses->iface_list with\nlist_for_each_entry_safe_from(), which captures the next entry\n(niface) under iface_lock.  The loop body then drops iface_lock for\nthe whole duration of cifs_ses_add_channel().\n\nA concurrent interface refresh (SMB3_request_interfaces() ->\nparse_server_interfaces()) marks all ifaces inactive and removes and\nfrees any that are not re-advertised via list_del() + kref_put(),\nwhere release_iface() is a bare kfree().  Since niface typically has\nno channel holding a reference, the list reference is its last and it\ncan be freed inside the unlocked window.  On continue, the iterator\nadvance step then dereferences niface->iface_head.next, and the loop\nbody reads iface->rdma_capable/is_active, both on freed memory.\n\nFix this by never keeping an unreferenced list pointer across the\nunlocked window.  Each channel attempt now re-scans the list from the\nhead under iface_lock, takes a kref on the selected candidate, and\npasses only that referenced candidate to cifs_ses_add_channel().\nweight_fulfilled still tracks selection progress, so restarting the\nscan preserves the original weighted distribution and the\nweight_fulfilled-before-kref_put ordering on the failure path.\n\nAdd a per-pass attempts cap so a flapping interface refresh cannot\nkeep the inner loop spinning within a single tries increment.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}