{"dataType": "CVE_RECORD", "dataVersion": "5.1", "cveMetadata": {"cveId": "CVE-2021-47103", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-02-29T22:33:44.301Z", "datePublished": "2024-03-04T18:10:57.116Z", "dateUpdated": "2024-11-04T11:59:27.947Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2024-11-04T11:59:27.947Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ninet: fully convert sk->sk_rx_dst to RCU rules\n\nsyzbot reported various issues around early demux,\none being included in this changelog [1]\n\nsk->sk_rx_dst is using RCU protection without clearly\ndocumenting it.\n\nAnd following sequences in tcp_v4_do_rcv()/tcp_v6_do_rcv()\nare not following standard RCU rules.\n\n[a] dst_release(dst);\n[b] sk->sk_rx_dst = NULL;\n\nThey look wrong because a delete operation of RCU protected\npointer is supposed to clear the pointer before\nthe call_rcu()/synchronize_rcu() guarding actual memory freeing.\n\nIn some cases indeed, dst could be freed before [b] is done.\n\nWe could cheat by clearing sk_rx_dst before calling\ndst_release(), but this seems the right time to stick\nto standard RCU annotations and debugging facilities.\n\n[1]\nBUG: KASAN: use-after-free in dst_check include/net/dst.h:470 [inline]\nBUG: KASAN: use-after-free in tcp_v4_early_demux+0x95b/0x960 net/ipv4/tcp_ipv4.c:1792\nRead of size 2 at addr ffff88807f1cb73a by task syz-executor.5/9204\n\nCPU: 0 PID: 9204 Comm: syz-executor.5 Not tainted 5.16.0-rc5-syzkaller #0\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011\nCall Trace:\n <TASK>\n __dump_stack lib/dump_stack.c:88 [inline]\n dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106\n print_address_description.constprop.0.cold+0x8d/0x320 mm/kasan/report.c:247\n __kasan_report mm/kasan/report.c:433 [inline]\n kasan_report.cold+0x83/0xdf mm/kasan/report.c:450\n dst_check include/net/dst.h:470 [inline]\n tcp_v4_early_demux+0x95b/0x960 net/ipv4/tcp_ipv4.c:1792\n ip_rcv_finish_core.constprop.0+0x15de/0x1e80 net/ipv4/ip_input.c:340\n ip_list_rcv_finish.constprop.0+0x1b2/0x6e0 net/ipv4/ip_input.c:583\n ip_sublist_rcv net/ipv4/ip_input.c:609 [inline]\n ip_list_rcv+0x34e/0x490 net/ipv4/ip_input.c:644\n __netif_receive_skb_list_ptype net/core/dev.c:5508 [inline]\n __netif_receive_skb_list_core+0x549/0x8e0 net/core/dev.c:5556\n __netif_receive_skb_list net/core/dev.c:5608 [inline]\n netif_receive_skb_list_internal+0x75e/0xd80 net/core/dev.c:5699\n gro_normal_list net/core/dev.c:5853 [inline]\n gro_normal_list net/core/dev.c:5849 [inline]\n napi_complete_done+0x1f1/0x880 net/core/dev.c:6590\n virtqueue_napi_complete drivers/net/virtio_net.c:339 [inline]\n virtnet_poll+0xca2/0x11b0 drivers/net/virtio_net.c:1557\n __napi_poll+0xaf/0x440 net/core/dev.c:7023\n napi_poll net/core/dev.c:7090 [inline]\n net_rx_action+0x801/0xb40 net/core/dev.c:7177\n __do_softirq+0x29b/0x9c2 kernel/softirq.c:558\n invoke_softirq kernel/softirq.c:432 [inline]\n __irq_exit_rcu+0x123/0x180 kernel/softirq.c:637\n irq_exit_rcu+0x5/0x20 kernel/softirq.c:649\n common_interrupt+0x52/0xc0 arch/x86/kernel/irq.c:240\n asm_common_interrupt+0x1e/0x40 arch/x86/include/asm/idtentry.h:629\nRIP: 0033:0x7f5e972bfd57\nCode: 39 d1 73 14 0f 1f 80 00 00 00 00 48 8b 50 f8 48 83 e8 08 48 39 ca 77 f3 48 39 c3 73 3e 48 89 13 48 8b 50 f8 48 89 38 49 8b 0e <48> 8b 3e 48 83 c3 08 48 83 c6 08 eb bc 48 39 d1 72 9e 48 39 d0 73\nRSP: 002b:00007fff8a413210 EFLAGS: 00000283\nRAX: 00007f5e97108990 RBX: 00007f5e97108338 RCX: ffffffff81d3aa45\nRDX: ffffffff81d3aa45 RSI: 00007f5e97108340 RDI: ffffffff81d3aa45\nRBP: 00007f5e97107eb8 R08: 00007f5e97108d88 R09: 0000000093c2e8d9\nR10: 0000000000000000 R11: 0000000000000000 R12: 00007f5e97107eb0\nR13: 00007f5e97108338 R14: 00007f5e97107ea8 R15: 0000000000000019\n </TASK>\n\nAllocated by task 13:\n kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38\n kasan_set_track mm/kasan/common.c:46 [inline]\n set_alloc_info mm/kasan/common.c:434 [inline]\n __kasan_slab_alloc+0x90/0xc0 mm/kasan/common.c:467\n kasan_slab_alloc include/linux/kasan.h:259 [inline]\n slab_post_alloc_hook mm/slab.h:519 [inline]\n slab_alloc_node mm/slub.c:3234 [inline]\n slab_alloc mm/slub.c:3242 [inline]\n kmem_cache_alloc+0x202/0x3a0 mm/slub.c:3247\n dst_alloc+0x146/0x1f0 net/core/dst.c:92\n rt_dst_alloc+0x73/0x430 net/ipv4/route.c:1613\n ip_route_input_slow+0x1817/0x3a20 net/ipv4/route.c:234\n---truncated---"}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["include/net/sock.h", "net/ipv4/af_inet.c", "net/ipv4/tcp.c", "net/ipv4/tcp_input.c", "net/ipv4/tcp_ipv4.c", "net/ipv4/udp.c", "net/ipv6/tcp_ipv6.c", "net/ipv6/udp.c"], "versions": [{"version": "41063e9dd119", "lessThan": "68c34ce11ef2", "status": "affected", "versionType": "git"}, {"version": "41063e9dd119", "lessThan": "92e6e36ecd16", "status": "affected", "versionType": "git"}, {"version": "41063e9dd119", "lessThan": "75a578000ae5", "status": "affected", "versionType": "git"}, {"version": "41063e9dd119", "lessThan": "c3bb4a7e8cbc", "status": "affected", "versionType": "git"}, {"version": "41063e9dd119", "lessThan": "f039b43cbaea", "status": "affected", "versionType": "git"}, {"version": "41063e9dd119", "lessThan": "0249a4b8a554", "status": "affected", "versionType": "git"}, {"version": "41063e9dd119", "lessThan": "8f905c0e7354", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["include/net/sock.h", "net/ipv4/af_inet.c", "net/ipv4/tcp.c", "net/ipv4/tcp_input.c", "net/ipv4/tcp_ipv4.c", "net/ipv4/udp.c", "net/ipv6/tcp_ipv6.c", "net/ipv6/udp.c"], "versions": [{"version": "3.6", "status": "affected"}, {"version": "0", "lessThan": "3.6", "status": "unaffected", "versionType": "semver"}, {"version": "4.9.331", "lessThanOrEqual": "4.9.*", "status": "unaffected", "versionType": "semver"}, {"version": "4.14.296", "lessThanOrEqual": "4.14.*", "status": "unaffected", "versionType": "semver"}, {"version": "4.19.262", "lessThanOrEqual": "4.19.*", "status": "unaffected", "versionType": "semver"}, {"version": "5.4.220", "lessThanOrEqual": "5.4.*", "status": "unaffected", "versionType": "semver"}, {"version": "5.10.150", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver"}, {"version": "5.15.12", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver"}, {"version": "5.16", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix"}]}], "references": [{"url": "https://git.kernel.org/stable/c/68c34ce11ef23328692aa35fa6aaafdd75913100"}, {"url": "https://git.kernel.org/stable/c/92e6e36ecd16808866ac6172b9491b5097cde449"}, {"url": "https://git.kernel.org/stable/c/75a578000ae5e511e5d0e8433c94a14d9c99c412"}, {"url": "https://git.kernel.org/stable/c/c3bb4a7e8cbc984e1cdac0fe6af60e880214ed6e"}, {"url": "https://git.kernel.org/stable/c/f039b43cbaea5e0700980c2f0052da05a70782e0"}, {"url": "https://git.kernel.org/stable/c/0249a4b8a554f2eb6a27b62516fa50168584faa4"}, {"url": "https://git.kernel.org/stable/c/8f905c0e7354ef261360fb7535ea079b1082c105"}], "title": "inet: fully convert sk->sk_rx_dst to RCU rules", "x_generator": {"engine": "bippy-9e1c9544281a"}}, "adp": [{"providerMetadata": {"orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2024-08-04T05:24:39.898Z"}, "title": "CVE Program Container", "references": [{"url": "https://git.kernel.org/stable/c/68c34ce11ef23328692aa35fa6aaafdd75913100", "tags": ["x_transferred"]}, {"url": "https://git.kernel.org/stable/c/92e6e36ecd16808866ac6172b9491b5097cde449", "tags": ["x_transferred"]}, {"url": "https://git.kernel.org/stable/c/75a578000ae5e511e5d0e8433c94a14d9c99c412", "tags": ["x_transferred"]}, {"url": "https://git.kernel.org/stable/c/c3bb4a7e8cbc984e1cdac0fe6af60e880214ed6e", "tags": ["x_transferred"]}, {"url": "https://git.kernel.org/stable/c/f039b43cbaea5e0700980c2f0052da05a70782e0", "tags": ["x_transferred"]}, {"url": "https://git.kernel.org/stable/c/0249a4b8a554f2eb6a27b62516fa50168584faa4", "tags": ["x_transferred"]}, {"url": "https://git.kernel.org/stable/c/8f905c0e7354ef261360fb7535ea079b1082c105", "tags": ["x_transferred"]}]}, {"metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2024-08-08T15:23:27.864349Z", "id": "CVE-2021-47103", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "role": "CISA Coordinator", "version": "2.0.3"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2024-08-08T15:23:36.672Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CVE Program Container", "references": [{"url": "https://git.kernel.org/stable/c/68c34ce11ef23328692aa35fa6aaafdd75913100", "tags": ["x_transferred"]}, {"url": "https://git.kernel.org/stable/c/92e6e36ecd16808866ac6172b9491b5097cde449", "tags": ["x_transferred"]}, {"url": "https://git.kernel.org/stable/c/75a578000ae5e511e5d0e8433c94a14d9c99c412", "tags": ["x_transferred"]}, {"url": "https://git.kernel.org/stable/c/c3bb4a7e8cbc984e1cdac0fe6af60e880214ed6e", "tags": ["x_transferred"]}, {"url": "https://git.kernel.org/stable/c/f039b43cbaea5e0700980c2f0052da05a70782e0", "tags": ["x_transferred"]}, {"url": "https://git.kernel.org/stable/c/0249a4b8a554f2eb6a27b62516fa50168584faa4", "tags": ["x_transferred"]}, {"url": "https://git.kernel.org/stable/c/8f905c0e7354ef261360fb7535ea079b1082c105", "tags": ["x_transferred"]}], "providerMetadata": {"orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2024-08-04T05:24:39.898Z"}}, {"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2021-47103", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2024-08-08T15:23:27.864349Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2024-08-08T15:23:32.433Z"}}], "cna": {"title": "inet: fully convert sk->sk_rx_dst to RCU rules", "affected": [{"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "41063e9dd119", "lessThan": "68c34ce11ef2", "versionType": "git"}, {"status": "affected", "version": "41063e9dd119", "lessThan": "92e6e36ecd16", "versionType": "git"}, {"status": "affected", "version": "41063e9dd119", "lessThan": "75a578000ae5", "versionType": "git"}, {"status": "affected", "version": "41063e9dd119", "lessThan": "c3bb4a7e8cbc", "versionType": "git"}, {"status": "affected", "version": "41063e9dd119", "lessThan": "f039b43cbaea", "versionType": "git"}, {"status": "affected", "version": "41063e9dd119", "lessThan": "0249a4b8a554", "versionType": "git"}, {"status": "affected", "version": "41063e9dd119", "lessThan": "8f905c0e7354", "versionType": "git"}], "programFiles": ["include/net/sock.h", "net/ipv4/af_inet.c", "net/ipv4/tcp.c", "net/ipv4/tcp_input.c", "net/ipv4/tcp_ipv4.c", "net/ipv4/udp.c", "net/ipv6/tcp_ipv6.c", "net/ipv6/udp.c"], "defaultStatus": "unaffected"}, {"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "3.6"}, {"status": "unaffected", "version": "0", "lessThan": "3.6", "versionType": "semver"}, {"status": "unaffected", "version": "4.9.331", "versionType": "semver", "lessThanOrEqual": "4.9.*"}, {"status": "unaffected", "version": "4.14.296", "versionType": "semver", "lessThanOrEqual": "4.14.*"}, {"status": "unaffected", "version": "4.19.262", "versionType": "semver", "lessThanOrEqual": "4.19.*"}, {"status": "unaffected", "version": "5.4.220", "versionType": "semver", "lessThanOrEqual": "5.4.*"}, {"status": "unaffected", "version": "5.10.150", "versionType": "semver", "lessThanOrEqual": "5.10.*"}, {"status": "unaffected", "version": "5.15.12", "versionType": "semver", "lessThanOrEqual": "5.15.*"}, {"status": "unaffected", "version": "5.16", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*"}], "programFiles": ["include/net/sock.h", "net/ipv4/af_inet.c", "net/ipv4/tcp.c", "net/ipv4/tcp_input.c", "net/ipv4/tcp_ipv4.c", "net/ipv4/udp.c", "net/ipv6/tcp_ipv6.c", "net/ipv6/udp.c"], "defaultStatus": "affected"}], "references": [{"url": "https://git.kernel.org/stable/c/68c34ce11ef23328692aa35fa6aaafdd75913100"}, {"url": "https://git.kernel.org/stable/c/92e6e36ecd16808866ac6172b9491b5097cde449"}, {"url": "https://git.kernel.org/stable/c/75a578000ae5e511e5d0e8433c94a14d9c99c412"}, {"url": "https://git.kernel.org/stable/c/c3bb4a7e8cbc984e1cdac0fe6af60e880214ed6e"}, {"url": "https://git.kernel.org/stable/c/f039b43cbaea5e0700980c2f0052da05a70782e0"}, {"url": "https://git.kernel.org/stable/c/0249a4b8a554f2eb6a27b62516fa50168584faa4"}, {"url": "https://git.kernel.org/stable/c/8f905c0e7354ef261360fb7535ea079b1082c105"}], "x_generator": {"engine": "bippy-9e1c9544281a"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ninet: fully convert sk->sk_rx_dst to RCU rules\n\nsyzbot reported various issues around early demux,\none being included in this changelog [1]\n\nsk->sk_rx_dst is using RCU protection without clearly\ndocumenting it.\n\nAnd following sequences in tcp_v4_do_rcv()/tcp_v6_do_rcv()\nare not following standard RCU rules.\n\n[a] dst_release(dst);\n[b] sk->sk_rx_dst = NULL;\n\nThey look wrong because a delete operation of RCU protected\npointer is supposed to clear the pointer before\nthe call_rcu()/synchronize_rcu() guarding actual memory freeing.\n\nIn some cases indeed, dst could be freed before [b] is done.\n\nWe could cheat by clearing sk_rx_dst before calling\ndst_release(), but this seems the right time to stick\nto standard RCU annotations and debugging facilities.\n\n[1]\nBUG: KASAN: use-after-free in dst_check include/net/dst.h:470 [inline]\nBUG: KASAN: use-after-free in tcp_v4_early_demux+0x95b/0x960 net/ipv4/tcp_ipv4.c:1792\nRead of size 2 at addr ffff88807f1cb73a by task syz-executor.5/9204\n\nCPU: 0 PID: 9204 Comm: syz-executor.5 Not tainted 5.16.0-rc5-syzkaller #0\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011\nCall Trace:\n <TASK>\n __dump_stack lib/dump_stack.c:88 [inline]\n dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106\n print_address_description.constprop.0.cold+0x8d/0x320 mm/kasan/report.c:247\n __kasan_report mm/kasan/report.c:433 [inline]\n kasan_report.cold+0x83/0xdf mm/kasan/report.c:450\n dst_check include/net/dst.h:470 [inline]\n tcp_v4_early_demux+0x95b/0x960 net/ipv4/tcp_ipv4.c:1792\n ip_rcv_finish_core.constprop.0+0x15de/0x1e80 net/ipv4/ip_input.c:340\n ip_list_rcv_finish.constprop.0+0x1b2/0x6e0 net/ipv4/ip_input.c:583\n ip_sublist_rcv net/ipv4/ip_input.c:609 [inline]\n ip_list_rcv+0x34e/0x490 net/ipv4/ip_input.c:644\n __netif_receive_skb_list_ptype net/core/dev.c:5508 [inline]\n __netif_receive_skb_list_core+0x549/0x8e0 net/core/dev.c:5556\n __netif_receive_skb_list net/core/dev.c:5608 [inline]\n netif_receive_skb_list_internal+0x75e/0xd80 net/core/dev.c:5699\n gro_normal_list net/core/dev.c:5853 [inline]\n gro_normal_list net/core/dev.c:5849 [inline]\n napi_complete_done+0x1f1/0x880 net/core/dev.c:6590\n virtqueue_napi_complete drivers/net/virtio_net.c:339 [inline]\n virtnet_poll+0xca2/0x11b0 drivers/net/virtio_net.c:1557\n __napi_poll+0xaf/0x440 net/core/dev.c:7023\n napi_poll net/core/dev.c:7090 [inline]\n net_rx_action+0x801/0xb40 net/core/dev.c:7177\n __do_softirq+0x29b/0x9c2 kernel/softirq.c:558\n invoke_softirq kernel/softirq.c:432 [inline]\n __irq_exit_rcu+0x123/0x180 kernel/softirq.c:637\n irq_exit_rcu+0x5/0x20 kernel/softirq.c:649\n common_interrupt+0x52/0xc0 arch/x86/kernel/irq.c:240\n asm_common_interrupt+0x1e/0x40 arch/x86/include/asm/idtentry.h:629\nRIP: 0033:0x7f5e972bfd57\nCode: 39 d1 73 14 0f 1f 80 00 00 00 00 48 8b 50 f8 48 83 e8 08 48 39 ca 77 f3 48 39 c3 73 3e 48 89 13 48 8b 50 f8 48 89 38 49 8b 0e <48> 8b 3e 48 83 c3 08 48 83 c6 08 eb bc 48 39 d1 72 9e 48 39 d0 73\nRSP: 002b:00007fff8a413210 EFLAGS: 00000283\nRAX: 00007f5e97108990 RBX: 00007f5e97108338 RCX: ffffffff81d3aa45\nRDX: ffffffff81d3aa45 RSI: 00007f5e97108340 RDI: ffffffff81d3aa45\nRBP: 00007f5e97107eb8 R08: 00007f5e97108d88 R09: 0000000093c2e8d9\nR10: 0000000000000000 R11: 0000000000000000 R12: 00007f5e97107eb0\nR13: 00007f5e97108338 R14: 00007f5e97107ea8 R15: 0000000000000019\n </TASK>\n\nAllocated by task 13:\n kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38\n kasan_set_track mm/kasan/common.c:46 [inline]\n set_alloc_info mm/kasan/common.c:434 [inline]\n __kasan_slab_alloc+0x90/0xc0 mm/kasan/common.c:467\n kasan_slab_alloc include/linux/kasan.h:259 [inline]\n slab_post_alloc_hook mm/slab.h:519 [inline]\n slab_alloc_node mm/slub.c:3234 [inline]\n slab_alloc mm/slub.c:3242 [inline]\n kmem_cache_alloc+0x202/0x3a0 mm/slub.c:3247\n dst_alloc+0x146/0x1f0 net/core/dst.c:92\n rt_dst_alloc+0x73/0x430 net/ipv4/route.c:1613\n ip_route_input_slow+0x1817/0x3a20 net/ipv4/route.c:234\n---truncated---"}], "providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2024-11-04T11:59:27.947Z"}}}, "cveMetadata": {"cveId": "CVE-2021-47103", "state": "PUBLISHED", "dateUpdated": "2024-11-04T11:59:27.947Z", "dateReserved": "2024-02-29T22:33:44.301Z", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "datePublished": "2024-03-04T18:10:57.116Z", "assignerShortName": "Linux"}, "dataVersion": "5.1"}

{"cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ninet: fully convert sk->sk_rx_dst to RCU rules\n\nsyzbot reported various issues around early demux,\none being included in this changelog [1]\n\nsk->sk_rx_dst is using RCU protection without clearly\ndocumenting it.\n\nAnd following sequences in tcp_v4_do_rcv()/tcp_v6_do_rcv()\nare not following standard RCU rules.\n\n[a] dst_release(dst);\n[b] sk->sk_rx_dst = NULL;\n\nThey look wrong because a delete operation of RCU protected\npointer is supposed to clear the pointer before\nthe call_rcu()/synchronize_rcu() guarding actual memory freeing.\n\nIn some cases indeed, dst could be freed before [b] is done.\n\nWe could cheat by clearing sk_rx_dst before calling\ndst_release(), but this seems the right time to stick\nto standard RCU annotations and debugging facilities.\n\n[1]\nBUG: KASAN: use-after-free in dst_check include/net/dst.h:470 [inline]\nBUG: KASAN: use-after-free in tcp_v4_early_demux+0x95b/0x960 net/ipv4/tcp_ipv4.c:1792\nRead of size 2 at addr ffff88807f1cb73a by task syz-executor.5/9204\n\nCPU: 0 PID: 9204 Comm: syz-executor.5 Not tainted 5.16.0-rc5-syzkaller #0\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011\nCall Trace:\n <TASK>\n __dump_stack lib/dump_stack.c:88 [inline]\n dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106\n print_address_description.constprop.0.cold+0x8d/0x320 mm/kasan/report.c:247\n __kasan_report mm/kasan/report.c:433 [inline]\n kasan_report.cold+0x83/0xdf mm/kasan/report.c:450\n dst_check include/net/dst.h:470 [inline]\n tcp_v4_early_demux+0x95b/0x960 net/ipv4/tcp_ipv4.c:1792\n ip_rcv_finish_core.constprop.0+0x15de/0x1e80 net/ipv4/ip_input.c:340\n ip_list_rcv_finish.constprop.0+0x1b2/0x6e0 net/ipv4/ip_input.c:583\n ip_sublist_rcv net/ipv4/ip_input.c:609 [inline]\n ip_list_rcv+0x34e/0x490 net/ipv4/ip_input.c:644\n __netif_receive_skb_list_ptype net/core/dev.c:5508 [inline]\n __netif_receive_skb_list_core+0x549/0x8e0 net/core/dev.c:5556\n __netif_receive_skb_list net/core/dev.c:5608 [inline]\n netif_receive_skb_list_internal+0x75e/0xd80 net/core/dev.c:5699\n gro_normal_list net/core/dev.c:5853 [inline]\n gro_normal_list net/core/dev.c:5849 [inline]\n napi_complete_done+0x1f1/0x880 net/core/dev.c:6590\n virtqueue_napi_complete drivers/net/virtio_net.c:339 [inline]\n virtnet_poll+0xca2/0x11b0 drivers/net/virtio_net.c:1557\n __napi_poll+0xaf/0x440 net/core/dev.c:7023\n napi_poll net/core/dev.c:7090 [inline]\n net_rx_action+0x801/0xb40 net/core/dev.c:7177\n __do_softirq+0x29b/0x9c2 kernel/softirq.c:558\n invoke_softirq kernel/softirq.c:432 [inline]\n __irq_exit_rcu+0x123/0x180 kernel/softirq.c:637\n irq_exit_rcu+0x5/0x20 kernel/softirq.c:649\n common_interrupt+0x52/0xc0 arch/x86/kernel/irq.c:240\n asm_common_interrupt+0x1e/0x40 arch/x86/include/asm/idtentry.h:629\nRIP: 0033:0x7f5e972bfd57\nCode: 39 d1 73 14 0f 1f 80 00 00 00 00 48 8b 50 f8 48 83 e8 08 48 39 ca 77 f3 48 39 c3 73 3e 48 89 13 48 8b 50 f8 48 89 38 49 8b 0e <48> 8b 3e 48 83 c3 08 48 83 c6 08 eb bc 48 39 d1 72 9e 48 39 d0 73\nRSP: 002b:00007fff8a413210 EFLAGS: 00000283\nRAX: 00007f5e97108990 RBX: 00007f5e97108338 RCX: ffffffff81d3aa45\nRDX: ffffffff81d3aa45 RSI: 00007f5e97108340 RDI: ffffffff81d3aa45\nRBP: 00007f5e97107eb8 R08: 00007f5e97108d88 R09: 0000000093c2e8d9\nR10: 0000000000000000 R11: 0000000000000000 R12: 00007f5e97107eb0\nR13: 00007f5e97108338 R14: 00007f5e97107ea8 R15: 0000000000000019\n </TASK>\n\nAllocated by task 13:\n kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38\n kasan_set_track mm/kasan/common.c:46 [inline]\n set_alloc_info mm/kasan/common.c:434 [inline]\n __kasan_slab_alloc+0x90/0xc0 mm/kasan/common.c:467\n kasan_slab_alloc include/linux/kasan.h:259 [inline]\n slab_post_alloc_hook mm/slab.h:519 [inline]\n slab_alloc_node mm/slub.c:3234 [inline]\n slab_alloc mm/slub.c:3242 [inline]\n kmem_cache_alloc+0x202/0x3a0 mm/slub.c:3247\n dst_alloc+0x146/0x1f0 net/core/dst.c:92\n rt_dst_alloc+0x73/0x430 net/ipv4/route.c:1613\n ip_route_input_slow+0x1817/0x3a20 net/ipv4/route.c:234\n---truncated---"}, {"lang": "es", "value": "En el kernel de Linux, se resolvi\u00f3 la siguiente vulnerabilidad: inet: conversi\u00f3n completa de sk-&gt;sk_rx_dst a reglas de RCU syzbot inform\u00f3 varios problemas relacionados con la demux inicial, uno de los cuales se incluye en este registro de cambios [1] sk-&gt;sk_rx_dst est\u00e1 usando protecci\u00f3n de RCU sin claridad document\u00e1ndolo. Y las siguientes secuencias en tcp_v4_do_rcv()/tcp_v6_do_rcv() no siguen las reglas est\u00e1ndar de RCU. [a] dst_release(dst); [b] sk-&gt;sk_rx_dst = NULL; Se ven incorrectos porque se supone que una operaci\u00f3n de eliminaci\u00f3n del puntero protegido de RCU borra el puntero antes de que call_rcu()/synchronize_rcu() proteja la liberaci\u00f3n de memoria real. De hecho, en algunos casos, dst podr\u00eda liberarse antes de que se realice [b]. Podr\u00edamos hacer trampa borrando sk_rx_dst antes de llamar a dst_release(), pero este parece el momento adecuado para ce\u00f1irnos a las anotaciones est\u00e1ndar de RCU y las funciones de depuraci\u00f3n. [1] BUG: KASAN: use-after-free in dst_check include/net/dst.h:470 [inline] BUG: KASAN: use-after-free in tcp_v4_early_demux+0x95b/0x960 net/ipv4/tcp_ipv4.c:1792 Read of size 2 at addr ffff88807f1cb73a by task syz-executor.5/9204 CPU: 0 PID: 9204 Comm: syz-executor.5 Not tainted 5.16.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description.constprop.0.cold+0x8d/0x320 mm/kasan/report.c:247 __kasan_report mm/kasan/report.c:433 [inline] kasan_report.cold+0x83/0xdf mm/kasan/report.c:450 dst_check include/net/dst.h:470 [inline] tcp_v4_early_demux+0x95b/0x960 net/ipv4/tcp_ipv4.c:1792 ip_rcv_finish_core.constprop.0+0x15de/0x1e80 net/ipv4/ip_input.c:340 ip_list_rcv_finish.constprop.0+0x1b2/0x6e0 net/ipv4/ip_input.c:583 ip_sublist_rcv net/ipv4/ip_input.c:609 [inline] ip_list_rcv+0x34e/0x490 net/ipv4/ip_input.c:644 __netif_receive_skb_list_ptype net/core/dev.c:5508 [inline] __netif_receive_skb_list_core+0x549/0x8e0 net/core/dev.c:5556 __netif_receive_skb_list net/core/dev.c:5608 [inline] netif_receive_skb_list_internal+0x75e/0xd80 net/core/dev.c:5699 gro_normal_list net/core/dev.c:5853 [inline] gro_normal_list net/core/dev.c:5849 [inline] napi_complete_done+0x1f1/0x880 net/core/dev.c:6590 virtqueue_napi_complete drivers/net/virtio_net.c:339 [inline] virtnet_poll+0xca2/0x11b0 drivers/net/virtio_net.c:1557 __napi_poll+0xaf/0x440 net/core/dev.c:7023 napi_poll net/core/dev.c:7090 [inline] net_rx_action+0x801/0xb40 net/core/dev.c:7177 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:637 irq_exit_rcu+0x5/0x20 kernel/softirq.c:649 common_interrupt+0x52/0xc0 arch/x86/kernel/irq.c:240 asm_common_interrupt+0x1e/0x40 arch/x86/include/asm/idtentry.h:629 RIP: 0033:0x7f5e972bfd57 Code: 39 d1 73 14 0f 1f 80 00 00 00 00 48 8b 50 f8 48 83 e8 08 48 39 ca 77 f3 48 39 c3 73 3e 48 89 13 48 8b 50 f8 48 89 38 49 8b 0e &lt;48&gt; 8b 3e 48 83 c3 08 48 83 c6 08 eb bc 48 39 d1 72 9e 48 39 d0 73 RSP: 002b:00007fff8a413210 EFLAGS: 00000283 RAX: 00007f5e97108990 RBX: 00007f5e97108338 RCX: ffffffff81d3aa45 RDX: ffffffff81d3aa45 RSI: 00007f5e97108340 RDI: ffffffff81d3aa45 RBP: 00007f5e97107eb8 R08: 00007f5e97108d88 R09: 0000000093c2e8d9 R10: 0000000000000000 R11: 0000000000000000 R12: 00007f5e97107eb0 R13: 00007f5e97108338 R14: 00007f5e97107ea8 R15: 0000000000000019 Allocated by task 13: kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] __kasan_slab_alloc+0x90/0xc0 mm/kasan/common.c:467 kasan_slab_alloc include/linux/kasan.h:259 [inline] slab_post_alloc_hook mm/slab.h:519 [inline] slab_alloc_node mm/slub.c:3234 [inline] slab_alloc mm/slub.c:3242 [inline] kmem_cache_alloc+0x202/0x3a0 mm/slub.c:3247 dst_alloc+0x146/0x1f0 net/core/dst.c:92 rt_dst_alloc+0x73/0x430 net/ipv4/route.c:1613 ip_route_input_slow+0x1817/0x3a20 net/ipv4/route.c:234"}], "id": "CVE-2021-47103", "lastModified": "2024-03-05T13:41:01.900", "metrics": {}, "published": "2024-03-04T18:15:08.667", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/0249a4b8a554f2eb6a27b62516fa50168584faa4"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/68c34ce11ef23328692aa35fa6aaafdd75913100"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/75a578000ae5e511e5d0e8433c94a14d9c99c412"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/8f905c0e7354ef261360fb7535ea079b1082c105"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/92e6e36ecd16808866ac6172b9491b5097cde449"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/c3bb4a7e8cbc984e1cdac0fe6af60e880214ed6e"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/f039b43cbaea5e0700980c2f0052da05a70782e0"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Awaiting Analysis"}

{"bugzilla": {"description": "kernel: inet: fully convert sk->sk_rx_dst to RCU rules", "id": "2267914", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2267914"}, "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-416", "details": ["In the Linux kernel, the following vulnerability has been resolved:\ninet: fully convert sk->sk_rx_dst to RCU rules\nsyzbot reported various issues around early demux,\none being included in this changelog [1]\nsk->sk_rx_dst is using RCU protection without clearly\ndocumenting it.\nAnd following sequences in tcp_v4_do_rcv()/tcp_v6_do_rcv()\nare not following standard RCU rules.\n[a] dst_release(dst);\n[b] sk->sk_rx_dst = NULL;\nThey look wrong because a delete operation of RCU protected\npointer is supposed to clear the pointer before\nthe call_rcu()/synchronize_rcu() guarding actual memory freeing.\nIn some cases indeed, dst could be freed before [b] is done.\nWe could cheat by clearing sk_rx_dst before calling\ndst_release(), but this seems the right time to stick\nto standard RCU annotations and debugging facilities.\n[1]\nBUG: KASAN: use-after-free in dst_check include/net/dst.h:470 [inline]\nBUG: KASAN: use-after-free in tcp_v4_early_demux+0x95b/0x960 net/ipv4/tcp_ipv4.c:1792\nRead of size 2 at addr ffff88807f1cb73a by task syz-executor.5/9204\nCPU: 0 PID: 9204 Comm: syz-executor.5 Not tainted 5.16.0-rc5-syzkaller #0\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011\nCall Trace:\n<TASK>\n__dump_stack lib/dump_stack.c:88 [inline]\ndump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106\nprint_address_description.constprop.0.cold+0x8d/0x320 mm/kasan/report.c:247\n__kasan_report mm/kasan/report.c:433 [inline]\nkasan_report.cold+0x83/0xdf mm/kasan/report.c:450\ndst_check include/net/dst.h:470 [inline]\ntcp_v4_early_demux+0x95b/0x960 net/ipv4/tcp_ipv4.c:1792\nip_rcv_finish_core.constprop.0+0x15de/0x1e80 net/ipv4/ip_input.c:340\nip_list_rcv_finish.constprop.0+0x1b2/0x6e0 net/ipv4/ip_input.c:583\nip_sublist_rcv net/ipv4/ip_input.c:609 [inline]\nip_list_rcv+0x34e/0x490 net/ipv4/ip_input.c:644\n__netif_receive_skb_list_ptype net/core/dev.c:5508 [inline]\n__netif_receive_skb_list_core+0x549/0x8e0 net/core/dev.c:5556\n__netif_receive_skb_list net/core/dev.c:5608 [inline]\nnetif_receive_skb_list_internal+0x75e/0xd80 net/core/dev.c:5699\ngro_normal_list net/core/dev.c:5853 [inline]\ngro_normal_list net/core/dev.c:5849 [inline]\nnapi_complete_done+0x1f1/0x880 net/core/dev.c:6590\nvirtqueue_napi_complete drivers/net/virtio_net.c:339 [inline]\nvirtnet_poll+0xca2/0x11b0 drivers/net/virtio_net.c:1557\n__napi_poll+0xaf/0x440 net/core/dev.c:7023\nnapi_poll net/core/dev.c:7090 [inline]\nnet_rx_action+0x801/0xb40 net/core/dev.c:7177\n__do_softirq+0x29b/0x9c2 kernel/softirq.c:558\ninvoke_softirq kernel/softirq.c:432 [inline]\n__irq_exit_rcu+0x123/0x180 kernel/softirq.c:637\nirq_exit_rcu+0x5/0x20 kernel/softirq.c:649\ncommon_interrupt+0x52/0xc0 arch/x86/kernel/irq.c:240\nasm_common_interrupt+0x1e/0x40 arch/x86/include/asm/idtentry.h:629\nRIP: 0033:0x7f5e972bfd57\nCode: 39 d1 73 14 0f 1f 80 00 00 00 00 48 8b 50 f8 48 83 e8 08 48 39 ca 77 f3 48 39 c3 73 3e 48 89 13 48 8b 50 f8 48 89 38 49 8b 0e <48> 8b 3e 48 83 c3 08 48 83 c6 08 eb bc 48 39 d1 72 9e 48 39 d0 73\nRSP: 002b:00007fff8a413210 EFLAGS: 00000283\nRAX: 00007f5e97108990 RBX: 00007f5e97108338 RCX: ffffffff81d3aa45\nRDX: ffffffff81d3aa45 RSI: 00007f5e97108340 RDI: ffffffff81d3aa45\nRBP: 00007f5e97107eb8 R08: 00007f5e97108d88 R09: 0000000093c2e8d9\nR10: 0000000000000000 R11: 0000000000000000 R12: 00007f5e97107eb0\nR13: 00007f5e97108338 R14: 00007f5e97107ea8 R15: 0000000000000019\n</TASK>\nAllocated by task 13:\nkasan_save_stack+0x1e/0x50 mm/kasan/common.c:38\nkasan_set_track mm/kasan/common.c:46 [inline]\nset_alloc_info mm/kasan/common.c:434 [inline]\n__kasan_slab_alloc+0x90/0xc0 mm/kasan/common.c:467\nkasan_slab_alloc include/linux/kasan.h:259 [inline]\nslab_post_alloc_hook mm/slab.h:519 [inline]\nslab_alloc_node mm/slub.c:3234 [inline]\nslab_alloc mm/slub.c:3242 [inline]\nkmem_cache_alloc+0x202/0x3a0 mm/slub.c:3247\ndst_alloc+0x146/0x1f0 net/core/dst.c:92\nrt_dst_alloc+0x73/0x430 net/ipv4/route.c:1613\nip_route_input_slow+0x1817/0x3a20 net/ipv4/route.c:234\n---truncated---", "A use-after-free vulnerability was found in the TCP IP protocol in the Linux Kernel, where a delete operation of the RCU-protected pointer is supposed to clear the pointer before the call_rcu()/synchronize_rcu() guarding the actual memory freeing. This flaw allows a local attacker to crash the system or leak kernel internal information."], "name": "CVE-2021-47103", "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": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2024-03-04T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2021-47103\nhttps://nvd.nist.gov/vuln/detail/CVE-2021-47103\nhttps://lore.kernel.org/linux-cve-announce/2024030416-CVE-2021-47103-4314@gregkh/T"], "threat_severity": "Moderate", "upstream_fix": "kernel 4.9.331, kernel 4.14.296, kernel 4.19.262, kernel 5.4.220, kernel 5.10.150, kernel 5.15.12, kernel 5.16"}