{"api_version":"1","generated_at":"2026-08-22T07:08:09+00:00","cve":"CVE-2021-47402","urls":{"html":"https://cve.report/CVE-2021-47402","api":"https://cve.report/api/cve/CVE-2021-47402.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2021-47402","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2021-47402"},"summary":{"title":"net: sched: flower: protect fl_walk() with rcu","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: sched: flower: protect fl_walk() with rcu\n\nPatch that refactored fl_walk() to use idr_for_each_entry_continue_ul()\nalso removed rcu protection of individual filters which causes following\nuse-after-free when filter is deleted concurrently. Fix fl_walk() to obtain\nrcu read lock while iterating and taking the filter reference and temporary\nrelease the lock while calling arg->fn() callback that can sleep.\n\nKASAN trace:\n\n[  352.773640] ==================================================================\n[  352.775041] BUG: KASAN: use-after-free in fl_walk+0x159/0x240 [cls_flower]\n[  352.776304] Read of size 4 at addr ffff8881c8251480 by task tc/2987\n\n[  352.777862] CPU: 3 PID: 2987 Comm: tc Not tainted 5.15.0-rc2+ #2\n[  352.778980] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014\n[  352.781022] Call Trace:\n[  352.781573]  dump_stack_lvl+0x46/0x5a\n[  352.782332]  print_address_description.constprop.0+0x1f/0x140\n[  352.783400]  ? fl_walk+0x159/0x240 [cls_flower]\n[  352.784292]  ? fl_walk+0x159/0x240 [cls_flower]\n[  352.785138]  kasan_report.cold+0x83/0xdf\n[  352.785851]  ? fl_walk+0x159/0x240 [cls_flower]\n[  352.786587]  kasan_check_range+0x145/0x1a0\n[  352.787337]  fl_walk+0x159/0x240 [cls_flower]\n[  352.788163]  ? fl_put+0x10/0x10 [cls_flower]\n[  352.789007]  ? __mutex_unlock_slowpath.constprop.0+0x220/0x220\n[  352.790102]  tcf_chain_dump+0x231/0x450\n[  352.790878]  ? tcf_chain_tp_delete_empty+0x170/0x170\n[  352.791833]  ? __might_sleep+0x2e/0xc0\n[  352.792594]  ? tfilter_notify+0x170/0x170\n[  352.793400]  ? __mutex_unlock_slowpath.constprop.0+0x220/0x220\n[  352.794477]  tc_dump_tfilter+0x385/0x4b0\n[  352.795262]  ? tc_new_tfilter+0x1180/0x1180\n[  352.796103]  ? __mod_node_page_state+0x1f/0xc0\n[  352.796974]  ? __build_skb_around+0x10e/0x130\n[  352.797826]  netlink_dump+0x2c0/0x560\n[  352.798563]  ? netlink_getsockopt+0x430/0x430\n[  352.799433]  ? __mutex_unlock_slowpath.constprop.0+0x220/0x220\n[  352.800542]  __netlink_dump_start+0x356/0x440\n[  352.801397]  rtnetlink_rcv_msg+0x3ff/0x550\n[  352.802190]  ? tc_new_tfilter+0x1180/0x1180\n[  352.802872]  ? rtnl_calcit.isra.0+0x1f0/0x1f0\n[  352.803668]  ? tc_new_tfilter+0x1180/0x1180\n[  352.804344]  ? _copy_from_iter_nocache+0x800/0x800\n[  352.805202]  ? kasan_set_track+0x1c/0x30\n[  352.805900]  netlink_rcv_skb+0xc6/0x1f0\n[  352.806587]  ? rht_deferred_worker+0x6b0/0x6b0\n[  352.807455]  ? rtnl_calcit.isra.0+0x1f0/0x1f0\n[  352.808324]  ? netlink_ack+0x4d0/0x4d0\n[  352.809086]  ? netlink_deliver_tap+0x62/0x3d0\n[  352.809951]  netlink_unicast+0x353/0x480\n[  352.810744]  ? netlink_attachskb+0x430/0x430\n[  352.811586]  ? __alloc_skb+0xd7/0x200\n[  352.812349]  netlink_sendmsg+0x396/0x680\n[  352.813132]  ? netlink_unicast+0x480/0x480\n[  352.813952]  ? __import_iovec+0x192/0x210\n[  352.814759]  ? netlink_unicast+0x480/0x480\n[  352.815580]  sock_sendmsg+0x6c/0x80\n[  352.816299]  ____sys_sendmsg+0x3a5/0x3c0\n[  352.817096]  ? kernel_sendmsg+0x30/0x30\n[  352.817873]  ? __ia32_sys_recvmmsg+0x150/0x150\n[  352.818753]  ___sys_sendmsg+0xd8/0x140\n[  352.819518]  ? sendmsg_copy_msghdr+0x110/0x110\n[  352.820402]  ? ___sys_recvmsg+0xf4/0x1a0\n[  352.821110]  ? __copy_msghdr_from_user+0x260/0x260\n[  352.821934]  ? _raw_spin_lock+0x81/0xd0\n[  352.822680]  ? __handle_mm_fault+0xef3/0x1b20\n[  352.823549]  ? rb_insert_color+0x2a/0x270\n[  352.824373]  ? copy_page_range+0x16b0/0x16b0\n[  352.825209]  ? perf_event_update_userpage+0x2d0/0x2d0\n[  352.826190]  ? __fget_light+0xd9/0xf0\n[  352.826941]  __sys_sendmsg+0xb3/0x130\n[  352.827613]  ? __sys_sendmsg_sock+0x20/0x20\n[  352.828377]  ? do_user_addr_fault+0x2c5/0x8a0\n[  352.829184]  ? fpregs_assert_state_consistent+0x52/0x60\n[  352.830001]  ? exit_to_user_mode_prepare+0x32/0x160\n[  352.830845]  do_syscall_64+0x35/0x80\n[  352.831445]  entry_SYSCALL_64_after_hwframe+0x44/0xae\n[  352.832331] RIP: 0033:0x7f7bee973c17\n[ \n---truncated---","state":"PUBLISHED","assigner":"Linux","published_at":"2024-05-21 15:15:25","updated_at":"2026-08-04 10:17:02"},"problem_types":["CWE-416"],"metrics":[{"version":"3.1","source":"nvd@nist.gov","type":"Primary","score":"7.8","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"}},{"version":"3.1","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","score":"7.8","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"}},{"version":"3.1","source":"CNA","type":"DECLARED","score":"7.8","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","data":{"baseScore":7.8,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"}}],"references":[{"url":"https://git.kernel.org/stable/c/d0d520c19e7ea19ed38dc5797b12397b6ccf9f88","name":"https://git.kernel.org/stable/c/d0d520c19e7ea19ed38dc5797b12397b6ccf9f88","refsource":"af854a3a-2127-422b-91ae-364da2661108","tags":["Patch"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/dab4677bdbffa5c8270e79e34e51c89efa0728a0","name":"https://git.kernel.org/stable/c/dab4677bdbffa5c8270e79e34e51c89efa0728a0","refsource":"af854a3a-2127-422b-91ae-364da2661108","tags":["Patch"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/d5ef190693a7d76c5c192d108e8dec48307b46ee","name":"https://git.kernel.org/stable/c/d5ef190693a7d76c5c192d108e8dec48307b46ee","refsource":"af854a3a-2127-422b-91ae-364da2661108","tags":["Patch"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/694b0cee7f8546b69a80996a29cb3cf4149c0453","name":"https://git.kernel.org/stable/c/694b0cee7f8546b69a80996a29cb3cf4149c0453","refsource":"af854a3a-2127-422b-91ae-364da2661108","tags":["Patch"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2021-47402","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-47402","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected d39d714969cda5cbda291402c8c6b1fb1047f42e 694b0cee7f8546b69a80996a29cb3cf4149c0453 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected d39d714969cda5cbda291402c8c6b1fb1047f42e d0d520c19e7ea19ed38dc5797b12397b6ccf9f88 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected d39d714969cda5cbda291402c8c6b1fb1047f42e dab4677bdbffa5c8270e79e34e51c89efa0728a0 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected d39d714969cda5cbda291402c8c6b1fb1047f42e d5ef190693a7d76c5c192d108e8dec48307b46ee git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 5.3","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.3 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.4.151 5.4.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.10.71 5.10.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.14.10 5.14.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.15 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[{"cve_year":"2021","cve_id":"47402","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"o","cpe4":"linux","cpe5":"linux_kernel","cpe6":"*","cpe7":"*","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"}],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"adp":[{"providerMetadata":{"dateUpdated":"2024-08-04T05:39:58.958Z","orgId":"af854a3a-2127-422b-91ae-364da2661108","shortName":"CVE"},"references":[{"tags":["x_transferred"],"url":"https://git.kernel.org/stable/c/694b0cee7f8546b69a80996a29cb3cf4149c0453"},{"tags":["x_transferred"],"url":"https://git.kernel.org/stable/c/d0d520c19e7ea19ed38dc5797b12397b6ccf9f88"},{"tags":["x_transferred"],"url":"https://git.kernel.org/stable/c/dab4677bdbffa5c8270e79e34e51c89efa0728a0"},{"tags":["x_transferred"],"url":"https://git.kernel.org/stable/c/d5ef190693a7d76c5c192d108e8dec48307b46ee"}],"title":"CVE Program Container"},{"metrics":[{"other":{"content":{"id":"CVE-2021-47402","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","timestamp":"2024-09-10T15:38:07.154281Z","version":"2.0.3"},"type":"ssvc"}}],"providerMetadata":{"dateUpdated":"2024-09-11T17:33:41.419Z","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP"},"title":"CISA ADP Vulnrichment"}],"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["net/sched/cls_flower.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"694b0cee7f8546b69a80996a29cb3cf4149c0453","status":"affected","version":"d39d714969cda5cbda291402c8c6b1fb1047f42e","versionType":"git"},{"lessThan":"d0d520c19e7ea19ed38dc5797b12397b6ccf9f88","status":"affected","version":"d39d714969cda5cbda291402c8c6b1fb1047f42e","versionType":"git"},{"lessThan":"dab4677bdbffa5c8270e79e34e51c89efa0728a0","status":"affected","version":"d39d714969cda5cbda291402c8c6b1fb1047f42e","versionType":"git"},{"lessThan":"d5ef190693a7d76c5c192d108e8dec48307b46ee","status":"affected","version":"d39d714969cda5cbda291402c8c6b1fb1047f42e","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["net/sched/cls_flower.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"5.3"},{"lessThan":"5.3","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"5.4.*","status":"unaffected","version":"5.4.151","versionType":"semver"},{"lessThanOrEqual":"5.10.*","status":"unaffected","version":"5.10.71","versionType":"semver"},{"lessThanOrEqual":"5.14.*","status":"unaffected","version":"5.14.10","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"5.15","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.4.151","versionStartIncluding":"5.3","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.10.71","versionStartIncluding":"5.3","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.14.10","versionStartIncluding":"5.3","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.15","versionStartIncluding":"5.3","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: sched: flower: protect fl_walk() with rcu\n\nPatch that refactored fl_walk() to use idr_for_each_entry_continue_ul()\nalso removed rcu protection of individual filters which causes following\nuse-after-free when filter is deleted concurrently. Fix fl_walk() to obtain\nrcu read lock while iterating and taking the filter reference and temporary\nrelease the lock while calling arg->fn() callback that can sleep.\n\nKASAN trace:\n\n[  352.773640] ==================================================================\n[  352.775041] BUG: KASAN: use-after-free in fl_walk+0x159/0x240 [cls_flower]\n[  352.776304] Read of size 4 at addr ffff8881c8251480 by task tc/2987\n\n[  352.777862] CPU: 3 PID: 2987 Comm: tc Not tainted 5.15.0-rc2+ #2\n[  352.778980] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014\n[  352.781022] Call Trace:\n[  352.781573]  dump_stack_lvl+0x46/0x5a\n[  352.782332]  print_address_description.constprop.0+0x1f/0x140\n[  352.783400]  ? fl_walk+0x159/0x240 [cls_flower]\n[  352.784292]  ? fl_walk+0x159/0x240 [cls_flower]\n[  352.785138]  kasan_report.cold+0x83/0xdf\n[  352.785851]  ? fl_walk+0x159/0x240 [cls_flower]\n[  352.786587]  kasan_check_range+0x145/0x1a0\n[  352.787337]  fl_walk+0x159/0x240 [cls_flower]\n[  352.788163]  ? fl_put+0x10/0x10 [cls_flower]\n[  352.789007]  ? __mutex_unlock_slowpath.constprop.0+0x220/0x220\n[  352.790102]  tcf_chain_dump+0x231/0x450\n[  352.790878]  ? tcf_chain_tp_delete_empty+0x170/0x170\n[  352.791833]  ? __might_sleep+0x2e/0xc0\n[  352.792594]  ? tfilter_notify+0x170/0x170\n[  352.793400]  ? __mutex_unlock_slowpath.constprop.0+0x220/0x220\n[  352.794477]  tc_dump_tfilter+0x385/0x4b0\n[  352.795262]  ? tc_new_tfilter+0x1180/0x1180\n[  352.796103]  ? __mod_node_page_state+0x1f/0xc0\n[  352.796974]  ? __build_skb_around+0x10e/0x130\n[  352.797826]  netlink_dump+0x2c0/0x560\n[  352.798563]  ? netlink_getsockopt+0x430/0x430\n[  352.799433]  ? __mutex_unlock_slowpath.constprop.0+0x220/0x220\n[  352.800542]  __netlink_dump_start+0x356/0x440\n[  352.801397]  rtnetlink_rcv_msg+0x3ff/0x550\n[  352.802190]  ? tc_new_tfilter+0x1180/0x1180\n[  352.802872]  ? rtnl_calcit.isra.0+0x1f0/0x1f0\n[  352.803668]  ? tc_new_tfilter+0x1180/0x1180\n[  352.804344]  ? _copy_from_iter_nocache+0x800/0x800\n[  352.805202]  ? kasan_set_track+0x1c/0x30\n[  352.805900]  netlink_rcv_skb+0xc6/0x1f0\n[  352.806587]  ? rht_deferred_worker+0x6b0/0x6b0\n[  352.807455]  ? rtnl_calcit.isra.0+0x1f0/0x1f0\n[  352.808324]  ? netlink_ack+0x4d0/0x4d0\n[  352.809086]  ? netlink_deliver_tap+0x62/0x3d0\n[  352.809951]  netlink_unicast+0x353/0x480\n[  352.810744]  ? netlink_attachskb+0x430/0x430\n[  352.811586]  ? __alloc_skb+0xd7/0x200\n[  352.812349]  netlink_sendmsg+0x396/0x680\n[  352.813132]  ? netlink_unicast+0x480/0x480\n[  352.813952]  ? __import_iovec+0x192/0x210\n[  352.814759]  ? netlink_unicast+0x480/0x480\n[  352.815580]  sock_sendmsg+0x6c/0x80\n[  352.816299]  ____sys_sendmsg+0x3a5/0x3c0\n[  352.817096]  ? kernel_sendmsg+0x30/0x30\n[  352.817873]  ? __ia32_sys_recvmmsg+0x150/0x150\n[  352.818753]  ___sys_sendmsg+0xd8/0x140\n[  352.819518]  ? sendmsg_copy_msghdr+0x110/0x110\n[  352.820402]  ? ___sys_recvmsg+0xf4/0x1a0\n[  352.821110]  ? __copy_msghdr_from_user+0x260/0x260\n[  352.821934]  ? _raw_spin_lock+0x81/0xd0\n[  352.822680]  ? __handle_mm_fault+0xef3/0x1b20\n[  352.823549]  ? rb_insert_color+0x2a/0x270\n[  352.824373]  ? copy_page_range+0x16b0/0x16b0\n[  352.825209]  ? perf_event_update_userpage+0x2d0/0x2d0\n[  352.826190]  ? __fget_light+0xd9/0xf0\n[  352.826941]  __sys_sendmsg+0xb3/0x130\n[  352.827613]  ? __sys_sendmsg_sock+0x20/0x20\n[  352.828377]  ? do_user_addr_fault+0x2c5/0x8a0\n[  352.829184]  ? fpregs_assert_state_consistent+0x52/0x60\n[  352.830001]  ? exit_to_user_mode_prepare+0x32/0x160\n[  352.830845]  do_syscall_64+0x35/0x80\n[  352.831445]  entry_SYSCALL_64_after_hwframe+0x44/0xae\n[  352.832331] RIP: 0033:0x7f7bee973c17\n[ \n---truncated---"}],"metrics":[{"cvssV3_1":{"baseScore":7.8,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"}}],"providerMetadata":{"dateUpdated":"2026-08-04T09:00:33.834Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/694b0cee7f8546b69a80996a29cb3cf4149c0453"},{"url":"https://git.kernel.org/stable/c/d0d520c19e7ea19ed38dc5797b12397b6ccf9f88"},{"url":"https://git.kernel.org/stable/c/dab4677bdbffa5c8270e79e34e51c89efa0728a0"},{"url":"https://git.kernel.org/stable/c/d5ef190693a7d76c5c192d108e8dec48307b46ee"}],"title":"net: sched: flower: protect fl_walk() with rcu","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2021-47402","datePublished":"2024-05-21T15:03:56.690Z","dateReserved":"2024-05-21T14:58:30.816Z","dateUpdated":"2026-08-04T09:00:33.834Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2024-05-21 15:15:25","lastModifiedDate":"2026-08-04 10:17:02","problem_types":["CWE-416"],"metrics":{"cvssMetricV31":[{"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"},"exploitabilityScore":1.8,"impactScore":5.9},{"source":"nvd@nist.gov","type":"Primary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"},"exploitabilityScore":1.8,"impactScore":5.9}],"ssvcV203":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","ssvcData":{"timestamp":"2024-09-10T15:38:07.154281Z","id":"CVE-2021-47402","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}]},"configurations":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.3","versionEndExcluding":"5.4.151","matchCriteriaId":"C11443A3-881A-4C77-84D2-DEC0F4B10883"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.5","versionEndExcluding":"5.10.71","matchCriteriaId":"60C740E4-6C54-40CD-A914-2232D8FC781D"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.11","versionEndExcluding":"5.14.10","matchCriteriaId":"1A437B0D-8305-4C72-B691-D26986A126CF"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:5.15:rc1:*:*:*:*:*:*","matchCriteriaId":"E46C74C6-B76B-4C94-A6A4-FD2FFF62D644"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:5.15:rc2:*:*:*:*:*:*","matchCriteriaId":"60134C3A-06E4-48C1-B04F-2903732A4E56"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:5.15:rc3:*:*:*:*:*:*","matchCriteriaId":"0460DA88-8FE1-46A2-9DDA-1F1ABA552E71"}]}]}]},"legacy_mitre":{"record":{"CveYear":"2021","CveId":"47402","Ordinal":"1","Title":"net: sched: flower: protect fl_walk() with rcu","CVE":"CVE-2021-47402","Year":"2021"},"notes":[{"CveYear":"2021","CveId":"47402","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: sched: flower: protect fl_walk() with rcu\n\nPatch that refactored fl_walk() to use idr_for_each_entry_continue_ul()\nalso removed rcu protection of individual filters which causes following\nuse-after-free when filter is deleted concurrently. Fix fl_walk() to obtain\nrcu read lock while iterating and taking the filter reference and temporary\nrelease the lock while calling arg->fn() callback that can sleep.\n\nKASAN trace:\n\n[  352.773640] ==================================================================\n[  352.775041] BUG: KASAN: use-after-free in fl_walk+0x159/0x240 [cls_flower]\n[  352.776304] Read of size 4 at addr ffff8881c8251480 by task tc/2987\n\n[  352.777862] CPU: 3 PID: 2987 Comm: tc Not tainted 5.15.0-rc2+ #2\n[  352.778980] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014\n[  352.781022] Call Trace:\n[  352.781573]  dump_stack_lvl+0x46/0x5a\n[  352.782332]  print_address_description.constprop.0+0x1f/0x140\n[  352.783400]  ? fl_walk+0x159/0x240 [cls_flower]\n[  352.784292]  ? fl_walk+0x159/0x240 [cls_flower]\n[  352.785138]  kasan_report.cold+0x83/0xdf\n[  352.785851]  ? fl_walk+0x159/0x240 [cls_flower]\n[  352.786587]  kasan_check_range+0x145/0x1a0\n[  352.787337]  fl_walk+0x159/0x240 [cls_flower]\n[  352.788163]  ? fl_put+0x10/0x10 [cls_flower]\n[  352.789007]  ? __mutex_unlock_slowpath.constprop.0+0x220/0x220\n[  352.790102]  tcf_chain_dump+0x231/0x450\n[  352.790878]  ? tcf_chain_tp_delete_empty+0x170/0x170\n[  352.791833]  ? __might_sleep+0x2e/0xc0\n[  352.792594]  ? tfilter_notify+0x170/0x170\n[  352.793400]  ? __mutex_unlock_slowpath.constprop.0+0x220/0x220\n[  352.794477]  tc_dump_tfilter+0x385/0x4b0\n[  352.795262]  ? tc_new_tfilter+0x1180/0x1180\n[  352.796103]  ? __mod_node_page_state+0x1f/0xc0\n[  352.796974]  ? __build_skb_around+0x10e/0x130\n[  352.797826]  netlink_dump+0x2c0/0x560\n[  352.798563]  ? netlink_getsockopt+0x430/0x430\n[  352.799433]  ? __mutex_unlock_slowpath.constprop.0+0x220/0x220\n[  352.800542]  __netlink_dump_start+0x356/0x440\n[  352.801397]  rtnetlink_rcv_msg+0x3ff/0x550\n[  352.802190]  ? tc_new_tfilter+0x1180/0x1180\n[  352.802872]  ? rtnl_calcit.isra.0+0x1f0/0x1f0\n[  352.803668]  ? tc_new_tfilter+0x1180/0x1180\n[  352.804344]  ? _copy_from_iter_nocache+0x800/0x800\n[  352.805202]  ? kasan_set_track+0x1c/0x30\n[  352.805900]  netlink_rcv_skb+0xc6/0x1f0\n[  352.806587]  ? rht_deferred_worker+0x6b0/0x6b0\n[  352.807455]  ? rtnl_calcit.isra.0+0x1f0/0x1f0\n[  352.808324]  ? netlink_ack+0x4d0/0x4d0\n[  352.809086]  ? netlink_deliver_tap+0x62/0x3d0\n[  352.809951]  netlink_unicast+0x353/0x480\n[  352.810744]  ? netlink_attachskb+0x430/0x430\n[  352.811586]  ? __alloc_skb+0xd7/0x200\n[  352.812349]  netlink_sendmsg+0x396/0x680\n[  352.813132]  ? netlink_unicast+0x480/0x480\n[  352.813952]  ? __import_iovec+0x192/0x210\n[  352.814759]  ? netlink_unicast+0x480/0x480\n[  352.815580]  sock_sendmsg+0x6c/0x80\n[  352.816299]  ____sys_sendmsg+0x3a5/0x3c0\n[  352.817096]  ? kernel_sendmsg+0x30/0x30\n[  352.817873]  ? __ia32_sys_recvmmsg+0x150/0x150\n[  352.818753]  ___sys_sendmsg+0xd8/0x140\n[  352.819518]  ? sendmsg_copy_msghdr+0x110/0x110\n[  352.820402]  ? ___sys_recvmsg+0xf4/0x1a0\n[  352.821110]  ? __copy_msghdr_from_user+0x260/0x260\n[  352.821934]  ? _raw_spin_lock+0x81/0xd0\n[  352.822680]  ? __handle_mm_fault+0xef3/0x1b20\n[  352.823549]  ? rb_insert_color+0x2a/0x270\n[  352.824373]  ? copy_page_range+0x16b0/0x16b0\n[  352.825209]  ? perf_event_update_userpage+0x2d0/0x2d0\n[  352.826190]  ? __fget_light+0xd9/0xf0\n[  352.826941]  __sys_sendmsg+0xb3/0x130\n[  352.827613]  ? __sys_sendmsg_sock+0x20/0x20\n[  352.828377]  ? do_user_addr_fault+0x2c5/0x8a0\n[  352.829184]  ? fpregs_assert_state_consistent+0x52/0x60\n[  352.830001]  ? exit_to_user_mode_prepare+0x32/0x160\n[  352.830845]  do_syscall_64+0x35/0x80\n[  352.831445]  entry_SYSCALL_64_after_hwframe+0x44/0xae\n[  352.832331] RIP: 0033:0x7f7bee973c17\n[ \n---truncated---","Type":"Description","Title":"net: sched: flower: protect fl_walk() with rcu"}]}}}