{"api_version":"1","generated_at":"2026-08-16T11:18:12+00:00","cve":"CVE-2026-74489","urls":{"html":"https://cve.report/CVE-2026-74489","api":"https://cve.report/api/cve/CVE-2026-74489.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-74489","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-74489"},"summary":{"title":"wifi: mac80211: fix tid_tx use-after-free on BA session stop","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nwifi: mac80211: fix tid_tx use-after-free on BA session stop\n\nieee80211_stop_tx_ba_cb() hands tid_tx to kfree_rcu() through\nieee80211_remove_tid_tx(), and then reads tid_tx->ndp after dropping\nsta->lock:\n\n\tieee80211_remove_tid_tx(sta, tid);\t/* kfree_rcu(tid_tx, rcu_head) */\n\t...\n\tspin_unlock_bh(&sta->lock);\n\n\tif (start_txq)\n\t\tieee80211_agg_start_txq(sta, tid, false);\n\n\tif (send_delba)\n\t\tieee80211_send_delba(..., tid_tx->ndp);\n\nThat read is not covered by an RCU read-side critical section, and it runs\nin preemptible process context: both callers hold the wiphy mutex, reaching\nit either from the ieee80211_ba_session_work() wiphy work or from\nieee80211_sta_tear_down_BA_sessions() during station teardown.\nSoftirqs can run in that window too, both from the local_bh_enable() that\nends ieee80211_agg_start_txq() and from any interrupt exit, so the RCU\ncallback can free tid_tx before the read.\n\nDriving the function from a test module with the grace period forced into\nthat window, KASAN reports the read, and the free arrives on the ordinary\nRCU softirq path:\n\n  BUG: KASAN: slab-use-after-free in ieee80211_stop_tx_ba_cb+0x3cd/0x400\n  Read of size 1 at addr ffff888002b9f52e by task kworker/0:1/10\n  [...]\n  Freed by task 57:\n   __kasan_slab_free+0x47/0x70\n   __rcu_free_sheaf_prepare+0x70/0x250\n   rcu_free_sheaf_nobarn+0x18/0x40\n   rcu_core+0x426/0x1310\n   handle_softirqs+0x144/0x590\n   __irq_exit_rcu+0xea/0x150\n   irq_exit_rcu+0x9/0x20\n   sysvec_apic_timer_interrupt+0x6b/0x80\n   asm_sysvec_apic_timer_interrupt+0x1a/0x20\n\nsend_delba is only set when tx_stop is set, which happens for\nAGG_STOP_LOCAL_REQUEST alone, so this is reached on local teardown -\nsession idle timeout, PTK rekey, suspend, HW reconfig - and not from a\npeer's DELBA.\n\nRead ndp into a local before the session is freed, while sta->lock is still\nheld. tid_tx->ndp has a single writer, in\nieee80211_tx_ba_session_handle_start(), which cannot run concurrently here:\nboth paths are serialised by the wiphy mutex, and the session is already\nmarked HT_AGG_STATE_STOPPING at this point. tid_tx->ndp is also the only\ntid_tx dereference left after ieee80211_remove_tid_tx() in this function.\n\n[move/change the comment a bit to be more general not just on ndp,\n initialize ndp directly]","state":"PUBLISHED","assigner":"Linux","published_at":"2026-08-15 13:17:53","updated_at":"2026-08-15 13:17:53"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/2f067f5a450ea07efd249142a11d940a068fe29c","name":"https://git.kernel.org/stable/c/2f067f5a450ea07efd249142a11d940a068fe29c","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/09fc36eec7841cdf732f4db39855e0c73bd075cc","name":"https://git.kernel.org/stable/c/09fc36eec7841cdf732f4db39855e0c73bd075cc","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-74489","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-74489","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 98acd4c1d9f7dc9c426e840c16e81b57315ff84b 09fc36eec7841cdf732f4db39855e0c73bd075cc git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 98acd4c1d9f7dc9c426e840c16e81b57315ff84b 2f067f5a450ea07efd249142a11d940a068fe29c git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 7.1","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1.8 7.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2-rc6 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["net/mac80211/agg-tx.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"09fc36eec7841cdf732f4db39855e0c73bd075cc","status":"affected","version":"98acd4c1d9f7dc9c426e840c16e81b57315ff84b","versionType":"git"},{"lessThan":"2f067f5a450ea07efd249142a11d940a068fe29c","status":"affected","version":"98acd4c1d9f7dc9c426e840c16e81b57315ff84b","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["net/mac80211/agg-tx.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"7.1"},{"lessThan":"7.1","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"7.1.*","status":"unaffected","version":"7.1.8","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.2-rc6","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.1.8","versionStartIncluding":"7.1","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2-rc6","versionStartIncluding":"7.1","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nwifi: mac80211: fix tid_tx use-after-free on BA session stop\n\nieee80211_stop_tx_ba_cb() hands tid_tx to kfree_rcu() through\nieee80211_remove_tid_tx(), and then reads tid_tx->ndp after dropping\nsta->lock:\n\n\tieee80211_remove_tid_tx(sta, tid);\t/* kfree_rcu(tid_tx, rcu_head) */\n\t...\n\tspin_unlock_bh(&sta->lock);\n\n\tif (start_txq)\n\t\tieee80211_agg_start_txq(sta, tid, false);\n\n\tif (send_delba)\n\t\tieee80211_send_delba(..., tid_tx->ndp);\n\nThat read is not covered by an RCU read-side critical section, and it runs\nin preemptible process context: both callers hold the wiphy mutex, reaching\nit either from the ieee80211_ba_session_work() wiphy work or from\nieee80211_sta_tear_down_BA_sessions() during station teardown.\nSoftirqs can run in that window too, both from the local_bh_enable() that\nends ieee80211_agg_start_txq() and from any interrupt exit, so the RCU\ncallback can free tid_tx before the read.\n\nDriving the function from a test module with the grace period forced into\nthat window, KASAN reports the read, and the free arrives on the ordinary\nRCU softirq path:\n\n  BUG: KASAN: slab-use-after-free in ieee80211_stop_tx_ba_cb+0x3cd/0x400\n  Read of size 1 at addr ffff888002b9f52e by task kworker/0:1/10\n  [...]\n  Freed by task 57:\n   __kasan_slab_free+0x47/0x70\n   __rcu_free_sheaf_prepare+0x70/0x250\n   rcu_free_sheaf_nobarn+0x18/0x40\n   rcu_core+0x426/0x1310\n   handle_softirqs+0x144/0x590\n   __irq_exit_rcu+0xea/0x150\n   irq_exit_rcu+0x9/0x20\n   sysvec_apic_timer_interrupt+0x6b/0x80\n   asm_sysvec_apic_timer_interrupt+0x1a/0x20\n\nsend_delba is only set when tx_stop is set, which happens for\nAGG_STOP_LOCAL_REQUEST alone, so this is reached on local teardown -\nsession idle timeout, PTK rekey, suspend, HW reconfig - and not from a\npeer's DELBA.\n\nRead ndp into a local before the session is freed, while sta->lock is still\nheld. tid_tx->ndp has a single writer, in\nieee80211_tx_ba_session_handle_start(), which cannot run concurrently here:\nboth paths are serialised by the wiphy mutex, and the session is already\nmarked HT_AGG_STATE_STOPPING at this point. tid_tx->ndp is also the only\ntid_tx dereference left after ieee80211_remove_tid_tx() in this function.\n\n[move/change the comment a bit to be more general not just on ndp,\n initialize ndp directly]"}],"providerMetadata":{"dateUpdated":"2026-08-15T12:27:19.505Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/09fc36eec7841cdf732f4db39855e0c73bd075cc"},{"url":"https://git.kernel.org/stable/c/2f067f5a450ea07efd249142a11d940a068fe29c"}],"title":"wifi: mac80211: fix tid_tx use-after-free on BA session stop","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-74489","datePublished":"2026-08-15T12:27:19.505Z","dateReserved":"2026-08-15T05:44:03.905Z","dateUpdated":"2026-08-15T12:27:19.505Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-08-15 13:17:53","lastModifiedDate":"2026-08-15 13:17:53","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"74489","Ordinal":"1","Title":"wifi: mac80211: fix tid_tx use-after-free on BA session stop","CVE":"CVE-2026-74489","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"74489","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nwifi: mac80211: fix tid_tx use-after-free on BA session stop\n\nieee80211_stop_tx_ba_cb() hands tid_tx to kfree_rcu() through\nieee80211_remove_tid_tx(), and then reads tid_tx->ndp after dropping\nsta->lock:\n\n\tieee80211_remove_tid_tx(sta, tid);\t/* kfree_rcu(tid_tx, rcu_head) */\n\t...\n\tspin_unlock_bh(&sta->lock);\n\n\tif (start_txq)\n\t\tieee80211_agg_start_txq(sta, tid, false);\n\n\tif (send_delba)\n\t\tieee80211_send_delba(..., tid_tx->ndp);\n\nThat read is not covered by an RCU read-side critical section, and it runs\nin preemptible process context: both callers hold the wiphy mutex, reaching\nit either from the ieee80211_ba_session_work() wiphy work or from\nieee80211_sta_tear_down_BA_sessions() during station teardown.\nSoftirqs can run in that window too, both from the local_bh_enable() that\nends ieee80211_agg_start_txq() and from any interrupt exit, so the RCU\ncallback can free tid_tx before the read.\n\nDriving the function from a test module with the grace period forced into\nthat window, KASAN reports the read, and the free arrives on the ordinary\nRCU softirq path:\n\n  BUG: KASAN: slab-use-after-free in ieee80211_stop_tx_ba_cb+0x3cd/0x400\n  Read of size 1 at addr ffff888002b9f52e by task kworker/0:1/10\n  [...]\n  Freed by task 57:\n   __kasan_slab_free+0x47/0x70\n   __rcu_free_sheaf_prepare+0x70/0x250\n   rcu_free_sheaf_nobarn+0x18/0x40\n   rcu_core+0x426/0x1310\n   handle_softirqs+0x144/0x590\n   __irq_exit_rcu+0xea/0x150\n   irq_exit_rcu+0x9/0x20\n   sysvec_apic_timer_interrupt+0x6b/0x80\n   asm_sysvec_apic_timer_interrupt+0x1a/0x20\n\nsend_delba is only set when tx_stop is set, which happens for\nAGG_STOP_LOCAL_REQUEST alone, so this is reached on local teardown -\nsession idle timeout, PTK rekey, suspend, HW reconfig - and not from a\npeer's DELBA.\n\nRead ndp into a local before the session is freed, while sta->lock is still\nheld. tid_tx->ndp has a single writer, in\nieee80211_tx_ba_session_handle_start(), which cannot run concurrently here:\nboth paths are serialised by the wiphy mutex, and the session is already\nmarked HT_AGG_STATE_STOPPING at this point. tid_tx->ndp is also the only\ntid_tx dereference left after ieee80211_remove_tid_tx() in this function.\n\n[move/change the comment a bit to be more general not just on ndp,\n initialize ndp directly]","Type":"Description","Title":"wifi: mac80211: fix tid_tx use-after-free on BA session stop"}]}}}