{"dataType": "CVE_RECORD", "dataVersion": "5.1", "cveMetadata": {"cveId": "CVE-2021-46954", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-02-27T18:42:55.937Z", "datePublished": "2024-02-27T18:46:56.804Z", "dateUpdated": "2025-05-04T07:01:06.292Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2025-05-04T07:01:06.292Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: sch_frag: fix stack OOB read while fragmenting IPv4 packets\n\nwhen 'act_mirred' tries to fragment IPv4 packets that had been previously\nre-assembled using 'act_ct', splats like the following can be observed on\nkernels built with KASAN:\n\n BUG: KASAN: stack-out-of-bounds in ip_do_fragment+0x1b03/0x1f60\n Read of size 1 at addr ffff888147009574 by task ping/947\n\n CPU: 0 PID: 947 Comm: ping Not tainted 5.12.0-rc6+ #418\n Hardware name: Red Hat KVM, BIOS 1.11.1-4.module+el8.1.0+4066+0f1aadab 04/01/2014\n Call Trace:\n <IRQ>\n dump_stack+0x92/0xc1\n print_address_description.constprop.7+0x1a/0x150\n kasan_report.cold.13+0x7f/0x111\n ip_do_fragment+0x1b03/0x1f60\n sch_fragment+0x4bf/0xe40\n tcf_mirred_act+0xc3d/0x11a0 [act_mirred]\n tcf_action_exec+0x104/0x3e0\n fl_classify+0x49a/0x5e0 [cls_flower]\n tcf_classify_ingress+0x18a/0x820\n __netif_receive_skb_core+0xae7/0x3340\n __netif_receive_skb_one_core+0xb6/0x1b0\n process_backlog+0x1ef/0x6c0\n __napi_poll+0xaa/0x500\n net_rx_action+0x702/0xac0\n __do_softirq+0x1e4/0x97f\n do_softirq+0x71/0x90\n </IRQ>\n __local_bh_enable_ip+0xdb/0xf0\n ip_finish_output2+0x760/0x2120\n ip_do_fragment+0x15a5/0x1f60\n __ip_finish_output+0x4c2/0xea0\n ip_output+0x1ca/0x4d0\n ip_send_skb+0x37/0xa0\n raw_sendmsg+0x1c4b/0x2d00\n sock_sendmsg+0xdb/0x110\n __sys_sendto+0x1d7/0x2b0\n __x64_sys_sendto+0xdd/0x1b0\n do_syscall_64+0x33/0x40\n entry_SYSCALL_64_after_hwframe+0x44/0xae\n RIP: 0033:0x7f82e13853eb\n Code: 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 f3 0f 1e fa 48 8d 05 75 42 2c 00 41 89 ca 8b 00 85 c0 75 14 b8 2c 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 75 c3 0f 1f 40 00 41 57 4d 89 c7 41 56 41 89\n RSP: 002b:00007ffe01fad888 EFLAGS: 00000246 ORIG_RAX: 000000000000002c\n RAX: ffffffffffffffda RBX: 00005571aac13700 RCX: 00007f82e13853eb\n RDX: 0000000000002330 RSI: 00005571aac13700 RDI: 0000000000000003\n RBP: 0000000000002330 R08: 00005571aac10500 R09: 0000000000000010\n R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe01faefb0\n R13: 00007ffe01fad890 R14: 00007ffe01fad980 R15: 00005571aac0f0a0\n\n The buggy address belongs to the page:\n page:000000001dff2e03 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x147009\n flags: 0x17ffffc0001000(reserved)\n raw: 0017ffffc0001000 ffffea00051c0248 ffffea00051c0248 0000000000000000\n raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000\n page dumped because: kasan: bad access detected\n\n Memory state around the buggy address:\n ffff888147009400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00\n ffff888147009480: f1 f1 f1 f1 04 f2 f2 f2 f2 f2 f2 f2 00 00 00 00\n >ffff888147009500: 00 00 00 00 00 00 00 00 00 00 f2 f2 f2 f2 f2 f2\n ^\n ffff888147009580: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00\n ffff888147009600: 00 00 00 00 00 00 00 00 00 00 00 00 00 f2 f2 f2\n\nfor IPv4 packets, sch_fragment() uses a temporary struct dst_entry. Then,\nin the following call graph:\n\n ip_do_fragment()\n ip_skb_dst_mtu()\n ip_dst_mtu_maybe_forward()\n ip_mtu_locked()\n\nthe pointer to struct dst_entry is used as pointer to struct rtable: this\nturns the access to struct members like rt_mtu_locked into an OOB read in\nthe stack. Fix this changing the temporary variable used for IPv4 packets\nin sch_fragment(), similarly to what is done for IPv6 few lines below."}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/sched/sch_frag.c"], "versions": [{"version": "c129412f74e99b609f0a8e95fc3915af1fd40f34", "lessThan": "018bb8da5b5888e19585f9b802f036afe643fcef", "status": "affected", "versionType": "git"}, {"version": "c129412f74e99b609f0a8e95fc3915af1fd40f34", "lessThan": "8e6dfb7beeb6489ac1365b8a71052e737f5da76e", "status": "affected", "versionType": "git"}, {"version": "c129412f74e99b609f0a8e95fc3915af1fd40f34", "lessThan": "31fe34a0118e0acc958c802e830ad5d37ef6b1d3", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/sched/sch_frag.c"], "versions": [{"version": "5.11", "status": "affected"}, {"version": "0", "lessThan": "5.11", "status": "unaffected", "versionType": "semver"}, {"version": "5.11.20", "lessThanOrEqual": "5.11.*", "status": "unaffected", "versionType": "semver"}, {"version": "5.12.3", "lessThanOrEqual": "5.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "5.13", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix"}]}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.11", "versionEndExcluding": "5.11.20"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.11", "versionEndExcluding": "5.12.3"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.11", "versionEndExcluding": "5.13"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/018bb8da5b5888e19585f9b802f036afe643fcef"}, {"url": "https://git.kernel.org/stable/c/8e6dfb7beeb6489ac1365b8a71052e737f5da76e"}, {"url": "https://git.kernel.org/stable/c/31fe34a0118e0acc958c802e830ad5d37ef6b1d3"}], "title": "net/sched: sch_frag: fix stack OOB read while fragmenting IPv4 packets", "x_generator": {"engine": "bippy-1.2.0"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2021-46954", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2024-02-27T19:36:31.837631Z"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2024-07-05T17:21:04.639Z"}}, {"providerMetadata": {"orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2024-08-04T05:17:42.983Z"}, "title": "CVE Program Container", "references": [{"url": "https://git.kernel.org/stable/c/018bb8da5b5888e19585f9b802f036afe643fcef", "tags": ["x_transferred"]}, {"url": "https://git.kernel.org/stable/c/8e6dfb7beeb6489ac1365b8a71052e737f5da76e", "tags": ["x_transferred"]}, {"url": "https://git.kernel.org/stable/c/31fe34a0118e0acc958c802e830ad5d37ef6b1d3", "tags": ["x_transferred"]}]}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CVE Program Container", "references": [{"url": "https://git.kernel.org/stable/c/018bb8da5b5888e19585f9b802f036afe643fcef", "tags": ["x_transferred"]}, {"url": "https://git.kernel.org/stable/c/8e6dfb7beeb6489ac1365b8a71052e737f5da76e", "tags": ["x_transferred"]}, {"url": "https://git.kernel.org/stable/c/31fe34a0118e0acc958c802e830ad5d37ef6b1d3", "tags": ["x_transferred"]}], "providerMetadata": {"orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2024-08-04T05:17:42.983Z"}}, {"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2021-46954", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2024-02-27T19:36:31.837631Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2024-07-05T15:20:37.773Z"}}], "cna": {"title": "net/sched: sch_frag: fix stack OOB read while fragmenting IPv4 packets", "affected": [{"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "c129412f74e99b609f0a8e95fc3915af1fd40f34", "lessThan": "018bb8da5b5888e19585f9b802f036afe643fcef", "versionType": "git"}, {"status": "affected", "version": "c129412f74e99b609f0a8e95fc3915af1fd40f34", "lessThan": "8e6dfb7beeb6489ac1365b8a71052e737f5da76e", "versionType": "git"}, {"status": "affected", "version": "c129412f74e99b609f0a8e95fc3915af1fd40f34", "lessThan": "31fe34a0118e0acc958c802e830ad5d37ef6b1d3", "versionType": "git"}], "programFiles": ["net/sched/sch_frag.c"], "defaultStatus": "unaffected"}, {"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "5.11"}, {"status": "unaffected", "version": "0", "lessThan": "5.11", "versionType": "semver"}, {"status": "unaffected", "version": "5.11.20", "versionType": "semver", "lessThanOrEqual": "5.11.*"}, {"status": "unaffected", "version": "5.12.3", "versionType": "semver", "lessThanOrEqual": "5.12.*"}, {"status": "unaffected", "version": "5.13", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*"}], "programFiles": ["net/sched/sch_frag.c"], "defaultStatus": "affected"}], "references": [{"url": "https://git.kernel.org/stable/c/018bb8da5b5888e19585f9b802f036afe643fcef"}, {"url": "https://git.kernel.org/stable/c/8e6dfb7beeb6489ac1365b8a71052e737f5da76e"}, {"url": "https://git.kernel.org/stable/c/31fe34a0118e0acc958c802e830ad5d37ef6b1d3"}], "x_generator": {"engine": "bippy-1.2.0"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: sch_frag: fix stack OOB read while fragmenting IPv4 packets\n\nwhen 'act_mirred' tries to fragment IPv4 packets that had been previously\nre-assembled using 'act_ct', splats like the following can be observed on\nkernels built with KASAN:\n\n BUG: KASAN: stack-out-of-bounds in ip_do_fragment+0x1b03/0x1f60\n Read of size 1 at addr ffff888147009574 by task ping/947\n\n CPU: 0 PID: 947 Comm: ping Not tainted 5.12.0-rc6+ #418\n Hardware name: Red Hat KVM, BIOS 1.11.1-4.module+el8.1.0+4066+0f1aadab 04/01/2014\n Call Trace:\n <IRQ>\n dump_stack+0x92/0xc1\n print_address_description.constprop.7+0x1a/0x150\n kasan_report.cold.13+0x7f/0x111\n ip_do_fragment+0x1b03/0x1f60\n sch_fragment+0x4bf/0xe40\n tcf_mirred_act+0xc3d/0x11a0 [act_mirred]\n tcf_action_exec+0x104/0x3e0\n fl_classify+0x49a/0x5e0 [cls_flower]\n tcf_classify_ingress+0x18a/0x820\n __netif_receive_skb_core+0xae7/0x3340\n __netif_receive_skb_one_core+0xb6/0x1b0\n process_backlog+0x1ef/0x6c0\n __napi_poll+0xaa/0x500\n net_rx_action+0x702/0xac0\n __do_softirq+0x1e4/0x97f\n do_softirq+0x71/0x90\n </IRQ>\n __local_bh_enable_ip+0xdb/0xf0\n ip_finish_output2+0x760/0x2120\n ip_do_fragment+0x15a5/0x1f60\n __ip_finish_output+0x4c2/0xea0\n ip_output+0x1ca/0x4d0\n ip_send_skb+0x37/0xa0\n raw_sendmsg+0x1c4b/0x2d00\n sock_sendmsg+0xdb/0x110\n __sys_sendto+0x1d7/0x2b0\n __x64_sys_sendto+0xdd/0x1b0\n do_syscall_64+0x33/0x40\n entry_SYSCALL_64_after_hwframe+0x44/0xae\n RIP: 0033:0x7f82e13853eb\n Code: 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 f3 0f 1e fa 48 8d 05 75 42 2c 00 41 89 ca 8b 00 85 c0 75 14 b8 2c 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 75 c3 0f 1f 40 00 41 57 4d 89 c7 41 56 41 89\n RSP: 002b:00007ffe01fad888 EFLAGS: 00000246 ORIG_RAX: 000000000000002c\n RAX: ffffffffffffffda RBX: 00005571aac13700 RCX: 00007f82e13853eb\n RDX: 0000000000002330 RSI: 00005571aac13700 RDI: 0000000000000003\n RBP: 0000000000002330 R08: 00005571aac10500 R09: 0000000000000010\n R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe01faefb0\n R13: 00007ffe01fad890 R14: 00007ffe01fad980 R15: 00005571aac0f0a0\n\n The buggy address belongs to the page:\n page:000000001dff2e03 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x147009\n flags: 0x17ffffc0001000(reserved)\n raw: 0017ffffc0001000 ffffea00051c0248 ffffea00051c0248 0000000000000000\n raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000\n page dumped because: kasan: bad access detected\n\n Memory state around the buggy address:\n ffff888147009400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00\n ffff888147009480: f1 f1 f1 f1 04 f2 f2 f2 f2 f2 f2 f2 00 00 00 00\n >ffff888147009500: 00 00 00 00 00 00 00 00 00 00 f2 f2 f2 f2 f2 f2\n ^\n ffff888147009580: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00\n ffff888147009600: 00 00 00 00 00 00 00 00 00 00 00 00 00 f2 f2 f2\n\nfor IPv4 packets, sch_fragment() uses a temporary struct dst_entry. Then,\nin the following call graph:\n\n ip_do_fragment()\n ip_skb_dst_mtu()\n ip_dst_mtu_maybe_forward()\n ip_mtu_locked()\n\nthe pointer to struct dst_entry is used as pointer to struct rtable: this\nturns the access to struct members like rt_mtu_locked into an OOB read in\nthe stack. Fix this changing the temporary variable used for IPv4 packets\nin sch_fragment(), similarly to what is done for IPv6 few lines below."}], "cpeApplicability": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "5.11.20", "versionStartIncluding": "5.11"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "5.12.3", "versionStartIncluding": "5.11"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "5.13", "versionStartIncluding": "5.11"}], "operator": "OR"}]}], "providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2025-05-04T07:01:06.292Z"}}}, "cveMetadata": {"cveId": "CVE-2021-46954", "state": "PUBLISHED", "dateUpdated": "2025-05-04T07:01:06.292Z", "dateReserved": "2024-02-27T18:42:55.937Z", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "datePublished": "2024-02-27T18:46:56.804Z", "assignerShortName": "Linux"}, "dataVersion": "5.1"}

{"configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "EFB425F0-C28C-4B44-8B4C-AD512AA832DE", "versionEndExcluding": "5.11.20", "versionStartIncluding": "5.11.0", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "C3814FA3-8141-4313-A852-8C4212BE12AD", "versionEndExcluding": "5.12.3", "versionStartIncluding": "5.12.0", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: sch_frag: fix stack OOB read while fragmenting IPv4 packets\n\nwhen 'act_mirred' tries to fragment IPv4 packets that had been previously\nre-assembled using 'act_ct', splats like the following can be observed on\nkernels built with KASAN:\n\n BUG: KASAN: stack-out-of-bounds in ip_do_fragment+0x1b03/0x1f60\n Read of size 1 at addr ffff888147009574 by task ping/947\n\n CPU: 0 PID: 947 Comm: ping Not tainted 5.12.0-rc6+ #418\n Hardware name: Red Hat KVM, BIOS 1.11.1-4.module+el8.1.0+4066+0f1aadab 04/01/2014\n Call Trace:\n <IRQ>\n dump_stack+0x92/0xc1\n print_address_description.constprop.7+0x1a/0x150\n kasan_report.cold.13+0x7f/0x111\n ip_do_fragment+0x1b03/0x1f60\n sch_fragment+0x4bf/0xe40\n tcf_mirred_act+0xc3d/0x11a0 [act_mirred]\n tcf_action_exec+0x104/0x3e0\n fl_classify+0x49a/0x5e0 [cls_flower]\n tcf_classify_ingress+0x18a/0x820\n __netif_receive_skb_core+0xae7/0x3340\n __netif_receive_skb_one_core+0xb6/0x1b0\n process_backlog+0x1ef/0x6c0\n __napi_poll+0xaa/0x500\n net_rx_action+0x702/0xac0\n __do_softirq+0x1e4/0x97f\n do_softirq+0x71/0x90\n </IRQ>\n __local_bh_enable_ip+0xdb/0xf0\n ip_finish_output2+0x760/0x2120\n ip_do_fragment+0x15a5/0x1f60\n __ip_finish_output+0x4c2/0xea0\n ip_output+0x1ca/0x4d0\n ip_send_skb+0x37/0xa0\n raw_sendmsg+0x1c4b/0x2d00\n sock_sendmsg+0xdb/0x110\n __sys_sendto+0x1d7/0x2b0\n __x64_sys_sendto+0xdd/0x1b0\n do_syscall_64+0x33/0x40\n entry_SYSCALL_64_after_hwframe+0x44/0xae\n RIP: 0033:0x7f82e13853eb\n Code: 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 f3 0f 1e fa 48 8d 05 75 42 2c 00 41 89 ca 8b 00 85 c0 75 14 b8 2c 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 75 c3 0f 1f 40 00 41 57 4d 89 c7 41 56 41 89\n RSP: 002b:00007ffe01fad888 EFLAGS: 00000246 ORIG_RAX: 000000000000002c\n RAX: ffffffffffffffda RBX: 00005571aac13700 RCX: 00007f82e13853eb\n RDX: 0000000000002330 RSI: 00005571aac13700 RDI: 0000000000000003\n RBP: 0000000000002330 R08: 00005571aac10500 R09: 0000000000000010\n R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe01faefb0\n R13: 00007ffe01fad890 R14: 00007ffe01fad980 R15: 00005571aac0f0a0\n\n The buggy address belongs to the page:\n page:000000001dff2e03 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x147009\n flags: 0x17ffffc0001000(reserved)\n raw: 0017ffffc0001000 ffffea00051c0248 ffffea00051c0248 0000000000000000\n raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000\n page dumped because: kasan: bad access detected\n\n Memory state around the buggy address:\n ffff888147009400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00\n ffff888147009480: f1 f1 f1 f1 04 f2 f2 f2 f2 f2 f2 f2 00 00 00 00\n >ffff888147009500: 00 00 00 00 00 00 00 00 00 00 f2 f2 f2 f2 f2 f2\n ^\n ffff888147009580: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00\n ffff888147009600: 00 00 00 00 00 00 00 00 00 00 00 00 00 f2 f2 f2\n\nfor IPv4 packets, sch_fragment() uses a temporary struct dst_entry. Then,\nin the following call graph:\n\n ip_do_fragment()\n ip_skb_dst_mtu()\n ip_dst_mtu_maybe_forward()\n ip_mtu_locked()\n\nthe pointer to struct dst_entry is used as pointer to struct rtable: this\nturns the access to struct members like rt_mtu_locked into an OOB read in\nthe stack. Fix this changing the temporary variable used for IPv4 packets\nin sch_fragment(), similarly to what is done for IPv6 few lines below."}, {"lang": "es", "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: net/sched: sch_frag: corrige la lectura OOB de la pila al fragmentar paquetes IPv4 cuando 'act_mirred' intenta fragmentar paquetes IPv4 que se hab\u00edan reensamblado previamente usando 'act_ct', s\u00edmbolos como el Se puede observar lo siguiente en los n\u00facleos creados con KASAN: ERROR: KASAN: pila fuera de los l\u00edmites en ip_do_fragment+0x1b03/0x1f60 Lectura de tama\u00f1o 1 en la direcci\u00f3n ffff888147009574 mediante tarea ping/947 CPU: 0 PID: 947 Comm: ping no contaminado 5.12.0-rc6+ #418 Nombre de hardware: Red Hat KVM, BIOS 1.11.1-4.module+el8.1.0+4066+0f1aadab 01/04/2014 Seguimiento de llamadas: dump_stack+0x92/0xc1 print_address_description.constprop. 7+0x1a/0x150 kasan_report.cold.13+0x7f/0x111 ip_do_fragment+0x1b03/0x1f60 sch_fragment+0x4bf/0xe40 tcf_mirred_act+0xc3d/0x11a0 [act_mirred] tcf_action_exec+0x104/0x3e0 fl_classify+0 x49a/0x5e0 [cls_flower] tcf_classify_ingress+0x18a/0x820 __netif_receive_skb_core+0xae7/0x3340 __netif_receive_skb_one_core+0xb6/0x1b0 Process_backlog+0x1ef/0x6c0 __napi_poll+0xaa/0x500 net_rx_action+0x702/0xac0 __do_softirq+0x1e4/0x97f do_softirq +0x71/0x90 __local_bh_enable_ip+0xdb/0xf0 ip_finish_output2+0x760/0x2120 ip_do_fragment +0x15a5/0x1f60 __ip_finish_output+0x4c2/0xea0 ip_output+0x1ca/0x4d0 ip_send_skb+0x37/0xa0 raw_sendmsg+0x1c4b/0x2d00 sock_sendmsg+0xdb/0x110 __sys_sendto+0x1d7/0x 2b0 __x64_sys_sendto+0xdd/0x1b0 do_syscall_64+0x33/0x40 Entry_SYSCALL_64_after_hwframe+0x44/0xae RIP : 0033:0x7f82e13853eb C\u00f3digo: 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 f3 0f 1e fa 48 8d 05 75 42 2c 00 41 89 ca 8b 00 85 c0 75 14 b8 2c 00 00 00 0f 05 &lt;48 &gt; 3d 00 f0 ff ff 77 75 c3 0f 1f 40 00 41 57 4d 89 c7 41 56 41 89 RSP: 002b:00007ffe01fad888 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffff ffffffffffda RBX: 00005571aac13700 RCX: 00007f82e13853eb RDX: 0000000000002330 RSI: 00005571aac13700 RDI: 0000000000000003 RBP: 0000000000002330 R08: 00005571aac10500 R09: 0000000000000010 R10: 00000000000000000 R11: 0000000000000246 R12: 00007ffe01faefb0 R13: 00007ffe01fad890 R14: 00007ffe01fad980 R15: 00005571aac0f0a0 La direcci\u00f3n del error pertenece a la p\u00e1gina: p\u00e1gina:000000001dff2e03 refcount:1 mapcount:0 mapeo:0000000000000000 \u00edndice: 0x0 pfn:0x147009 banderas: 0x17ffffc0001000(reservado) raw: 0017ffffc0001000 ffffea00051c0248 ffffea00051c0248 0000000000000000 raw: 0000000000000000 0000 000000000000 00000001ffffffff 00000000000000000 p\u00e1gina volcada porque: kasan: se detect\u00f3 mal acceso Estado de la memoria alrededor de la direcci\u00f3n con errores: ffff888147009400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888147009480: f1 f1 f1 f1 04 f2 f2 f2 f2 f2 f2 f2 00 00 00 00 &gt;ffff888147009500: 00 00 00 00 00 00 00 00 00 00 f2 f2 f2 f 2 f2 f2^ffff888147009580: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888147009600: 00 00 00 00 00 00 00 00 00 00 00 00 00 f2 f2 f2 para paquetes IPv4, sch_fragment() utiliza una estructura temporal dst_entry. Luego, en el siguiente gr\u00e1fico de llamadas: ip_do_fragment() ip_skb_dst_mtu() ip_dst_mtu_maybe_forward() ip_mtu_locked() el puntero a struct dst_entry se usa como puntero a struct rtable: esto convierte el acceso a miembros de estructura como rt_mtu_locked en una lectura OOB en la pila. Solucione este problema cambiando la variable temporal utilizada para los paquetes IPv4 en sch_fragment(), de manera similar a lo que se hace para IPv6 unas l\u00edneas m\u00e1s abajo."}], "id": "CVE-2021-46954", "lastModified": "2024-11-21T06:35:01.267", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 7.1, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "NONE", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 5.2, "source": "nvd@nist.gov", "type": "Primary"}]}, "published": "2024-02-27T19:04:06.617", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/018bb8da5b5888e19585f9b802f036afe643fcef"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/31fe34a0118e0acc958c802e830ad5d37ef6b1d3"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/8e6dfb7beeb6489ac1365b8a71052e737f5da76e"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/018bb8da5b5888e19585f9b802f036afe643fcef"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/31fe34a0118e0acc958c802e830ad5d37ef6b1d3"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/8e6dfb7beeb6489ac1365b8a71052e737f5da76e"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Modified", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-125"}], "source": "nvd@nist.gov", "type": "Primary"}]}

{"bugzilla": {"description": "kernel: net/sched: sch_frag: fix stack OOB read while fragmenting IPv4 packets", "id": "2266501", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2266501"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.1", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H", "status": "draft"}, "cwe": "CWE-125", "details": ["In the Linux kernel, the following vulnerability has been resolved:\nnet/sched: sch_frag: fix stack OOB read while fragmenting IPv4 packets\nwhen 'act_mirred' tries to fragment IPv4 packets that had been previously\nre-assembled using 'act_ct', splats like the following can be observed on\nkernels built with KASAN:\nBUG: KASAN: stack-out-of-bounds in ip_do_fragment+0x1b03/0x1f60\nRead of size 1 at addr ffff888147009574 by task ping/947\nCPU: 0 PID: 947 Comm: ping Not tainted 5.12.0-rc6+ #418\nHardware name: Red Hat KVM, BIOS 1.11.1-4.module+el8.1.0+4066+0f1aadab 04/01/2014\nCall Trace:\n<IRQ>\ndump_stack+0x92/0xc1\nprint_address_description.constprop.7+0x1a/0x150\nkasan_report.cold.13+0x7f/0x111\nip_do_fragment+0x1b03/0x1f60\nsch_fragment+0x4bf/0xe40\ntcf_mirred_act+0xc3d/0x11a0 [act_mirred]\ntcf_action_exec+0x104/0x3e0\nfl_classify+0x49a/0x5e0 [cls_flower]\ntcf_classify_ingress+0x18a/0x820\n__netif_receive_skb_core+0xae7/0x3340\n__netif_receive_skb_one_core+0xb6/0x1b0\nprocess_backlog+0x1ef/0x6c0\n__napi_poll+0xaa/0x500\nnet_rx_action+0x702/0xac0\n__do_softirq+0x1e4/0x97f\ndo_softirq+0x71/0x90\n</IRQ>\n__local_bh_enable_ip+0xdb/0xf0\nip_finish_output2+0x760/0x2120\nip_do_fragment+0x15a5/0x1f60\n__ip_finish_output+0x4c2/0xea0\nip_output+0x1ca/0x4d0\nip_send_skb+0x37/0xa0\nraw_sendmsg+0x1c4b/0x2d00\nsock_sendmsg+0xdb/0x110\n__sys_sendto+0x1d7/0x2b0\n__x64_sys_sendto+0xdd/0x1b0\ndo_syscall_64+0x33/0x40\nentry_SYSCALL_64_after_hwframe+0x44/0xae\nRIP: 0033:0x7f82e13853eb\nCode: 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 f3 0f 1e fa 48 8d 05 75 42 2c 00 41 89 ca 8b 00 85 c0 75 14 b8 2c 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 75 c3 0f 1f 40 00 41 57 4d 89 c7 41 56 41 89\nRSP: 002b:00007ffe01fad888 EFLAGS: 00000246 ORIG_RAX: 000000000000002c\nRAX: ffffffffffffffda RBX: 00005571aac13700 RCX: 00007f82e13853eb\nRDX: 0000000000002330 RSI: 00005571aac13700 RDI: 0000000000000003\nRBP: 0000000000002330 R08: 00005571aac10500 R09: 0000000000000010\nR10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe01faefb0\nR13: 00007ffe01fad890 R14: 00007ffe01fad980 R15: 00005571aac0f0a0\nThe buggy address belongs to the page:\npage:000000001dff2e03 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x147009\nflags: 0x17ffffc0001000(reserved)\nraw: 0017ffffc0001000 ffffea00051c0248 ffffea00051c0248 0000000000000000\nraw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000\npage dumped because: kasan: bad access detected\nMemory state around the buggy address:\nffff888147009400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00\nffff888147009480: f1 f1 f1 f1 04 f2 f2 f2 f2 f2 f2 f2 00 00 00 00\n>ffff888147009500: 00 00 00 00 00 00 00 00 00 00 f2 f2 f2 f2 f2 f2\n^\nffff888147009580: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00\nffff888147009600: 00 00 00 00 00 00 00 00 00 00 00 00 00 f2 f2 f2\nfor IPv4 packets, sch_fragment() uses a temporary struct dst_entry. Then,\nin the following call graph:\nip_do_fragment()\nip_skb_dst_mtu()\nip_dst_mtu_maybe_forward()\nip_mtu_locked()\nthe pointer to struct dst_entry is used as pointer to struct rtable: this\nturns the access to struct members like rt_mtu_locked into an OOB read in\nthe stack. Fix this changing the temporary variable used for IPv4 packets\nin sch_fragment(), similarly to what is done for IPv6 few lines below."], "name": "CVE-2021-46954", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Out of support scope", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Out of support scope", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Out of support scope", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2024-02-27T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2021-46954\nhttps://nvd.nist.gov/vuln/detail/CVE-2021-46954\nhttps://lore.kernel.org/linux-cve-announce/2024022715-CVE-2021-46954-b856@gregkh/T/#u"], "threat_severity": "Low"}

{}