{"dataType": "CVE_RECORD", "dataVersion": "5.1", "cveMetadata": {"cveId": "CVE-2025-39955", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-04-16T07:20:57.149Z", "datePublished": "2025-10-09T09:47:33.556Z", "dateUpdated": "2025-10-09T09:47:33.556Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2025-10-09T09:47:33.556Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ntcp: Clear tcp_sk(sk)->fastopen_rsk in tcp_disconnect().\n\nsyzbot reported the splat below where a socket had tcp_sk(sk)->fastopen_rsk\nin the TCP_ESTABLISHED state. [0]\n\nsyzbot reused the server-side TCP Fast Open socket as a new client before\nthe TFO socket completes 3WHS:\n\n 1. accept()\n 2. connect(AF_UNSPEC)\n 3. connect() to another destination\n\nAs of accept(), sk->sk_state is TCP_SYN_RECV, and tcp_disconnect() changes\nit to TCP_CLOSE and makes connect() possible, which restarts timers.\n\nSince tcp_disconnect() forgot to clear tcp_sk(sk)->fastopen_rsk, the\nretransmit timer triggered the warning and the intended packet was not\nretransmitted.\n\nLet's call reqsk_fastopen_remove() in tcp_disconnect().\n\n[0]:\nWARNING: CPU: 2 PID: 0 at net/ipv4/tcp_timer.c:542 tcp_retransmit_timer (net/ipv4/tcp_timer.c:542 (discriminator 7))\nModules linked in:\nCPU: 2 UID: 0 PID: 0 Comm: swapper/2 Not tainted 6.17.0-rc5-g201825fb4278 #62 PREEMPT(voluntary)\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014\nRIP: 0010:tcp_retransmit_timer (net/ipv4/tcp_timer.c:542 (discriminator 7))\nCode: 41 55 41 54 55 53 48 8b af b8 08 00 00 48 89 fb 48 85 ed 0f 84 55 01 00 00 0f b6 47 12 3c 03 74 0c 0f b6 47 12 3c 04 74 04 90 <0f> 0b 90 48 8b 85 c0 00 00 00 48 89 ef 48 8b 40 30 e8 6a 4f 06 3e\nRSP: 0018:ffffc900002f8d40 EFLAGS: 00010293\nRAX: 0000000000000002 RBX: ffff888106911400 RCX: 0000000000000017\nRDX: 0000000002517619 RSI: ffffffff83764080 RDI: ffff888106911400\nRBP: ffff888106d5c000 R08: 0000000000000001 R09: ffffc900002f8de8\nR10: 00000000000000c2 R11: ffffc900002f8ff8 R12: ffff888106911540\nR13: ffff888106911480 R14: ffff888106911840 R15: ffffc900002f8de0\nFS: 0000000000000000(0000) GS:ffff88907b768000(0000) knlGS:0000000000000000\nCS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\nCR2: 00007f8044d69d90 CR3: 0000000002c30003 CR4: 0000000000370ef0\nCall Trace:\n <IRQ>\n tcp_write_timer (net/ipv4/tcp_timer.c:738)\n call_timer_fn (kernel/time/timer.c:1747)\n __run_timers (kernel/time/timer.c:1799 kernel/time/timer.c:2372)\n timer_expire_remote (kernel/time/timer.c:2385 kernel/time/timer.c:2376 kernel/time/timer.c:2135)\n tmigr_handle_remote_up (kernel/time/timer_migration.c:944 kernel/time/timer_migration.c:1035)\n __walk_groups.isra.0 (kernel/time/timer_migration.c:533 (discriminator 1))\n tmigr_handle_remote (kernel/time/timer_migration.c:1096)\n handle_softirqs (./arch/x86/include/asm/jump_label.h:36 ./include/trace/events/irq.h:142 kernel/softirq.c:580)\n irq_exit_rcu (kernel/softirq.c:614 kernel/softirq.c:453 kernel/softirq.c:680 kernel/softirq.c:696)\n sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1050 (discriminator 35) arch/x86/kernel/apic/apic.c:1050 (discriminator 35))\n </IRQ>"}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/ipv4/tcp.c"], "versions": [{"version": "8336886f786fdacbc19b719c1f7ea91eb70706d4", "lessThan": "7ec092a91ff351dcde89c23e795b73a328274db6", "status": "affected", "versionType": "git"}, {"version": "8336886f786fdacbc19b719c1f7ea91eb70706d4", "lessThan": "a4378dedd6e07e62f2fccb17d78c9665718763d0", "status": "affected", "versionType": "git"}, {"version": "8336886f786fdacbc19b719c1f7ea91eb70706d4", "lessThan": "33a4fdf0b4a25f8ce65380c3b0136b407ca57609", "status": "affected", "versionType": "git"}, {"version": "8336886f786fdacbc19b719c1f7ea91eb70706d4", "lessThan": "17d699727577814198d744d6afe54735c6b54c99", "status": "affected", "versionType": "git"}, {"version": "8336886f786fdacbc19b719c1f7ea91eb70706d4", "lessThan": "dfd06131107e7b699ef1e2a24ed2f7d17c917753", "status": "affected", "versionType": "git"}, {"version": "8336886f786fdacbc19b719c1f7ea91eb70706d4", "lessThan": "fa4749c065644af4db496b338452a69a3e5147d9", "status": "affected", "versionType": "git"}, {"version": "8336886f786fdacbc19b719c1f7ea91eb70706d4", "lessThan": "ae313d14b45eca7a6bb29cb9bf396d977e7d28fb", "status": "affected", "versionType": "git"}, {"version": "8336886f786fdacbc19b719c1f7ea91eb70706d4", "lessThan": "45c8a6cc2bcd780e634a6ba8e46bffbdf1fc5c01", "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/ipv4/tcp.c"], "versions": [{"version": "3.7", "status": "affected"}, {"version": "0", "lessThan": "3.7", "status": "unaffected", "versionType": "semver"}, {"version": "5.4.300", "lessThanOrEqual": "5.4.*", "status": "unaffected", "versionType": "semver"}, {"version": "5.10.245", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver"}, {"version": "5.15.194", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.1.154", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.108", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.49", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.16.9", "lessThanOrEqual": "6.16.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.17", "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": "3.7", "versionEndExcluding": "5.4.300"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.7", "versionEndExcluding": "5.10.245"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.7", "versionEndExcluding": "5.15.194"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.7", "versionEndExcluding": "6.1.154"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.7", "versionEndExcluding": "6.6.108"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.7", "versionEndExcluding": "6.12.49"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.7", "versionEndExcluding": "6.16.9"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.7", "versionEndExcluding": "6.17"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/7ec092a91ff351dcde89c23e795b73a328274db6"}, {"url": "https://git.kernel.org/stable/c/a4378dedd6e07e62f2fccb17d78c9665718763d0"}, {"url": "https://git.kernel.org/stable/c/33a4fdf0b4a25f8ce65380c3b0136b407ca57609"}, {"url": "https://git.kernel.org/stable/c/17d699727577814198d744d6afe54735c6b54c99"}, {"url": "https://git.kernel.org/stable/c/dfd06131107e7b699ef1e2a24ed2f7d17c917753"}, {"url": "https://git.kernel.org/stable/c/fa4749c065644af4db496b338452a69a3e5147d9"}, {"url": "https://git.kernel.org/stable/c/ae313d14b45eca7a6bb29cb9bf396d977e7d28fb"}, {"url": "https://git.kernel.org/stable/c/45c8a6cc2bcd780e634a6ba8e46bffbdf1fc5c01"}], "title": "tcp: Clear tcp_sk(sk)->fastopen_rsk in tcp_disconnect().", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ntcp: Clear tcp_sk(sk)->fastopen_rsk in tcp_disconnect().\n\nsyzbot reported the splat below where a socket had tcp_sk(sk)->fastopen_rsk\nin the TCP_ESTABLISHED state. [0]\n\nsyzbot reused the server-side TCP Fast Open socket as a new client before\nthe TFO socket completes 3WHS:\n\n 1. accept()\n 2. connect(AF_UNSPEC)\n 3. connect() to another destination\n\nAs of accept(), sk->sk_state is TCP_SYN_RECV, and tcp_disconnect() changes\nit to TCP_CLOSE and makes connect() possible, which restarts timers.\n\nSince tcp_disconnect() forgot to clear tcp_sk(sk)->fastopen_rsk, the\nretransmit timer triggered the warning and the intended packet was not\nretransmitted.\n\nLet's call reqsk_fastopen_remove() in tcp_disconnect().\n\n[0]:\nWARNING: CPU: 2 PID: 0 at net/ipv4/tcp_timer.c:542 tcp_retransmit_timer (net/ipv4/tcp_timer.c:542 (discriminator 7))\nModules linked in:\nCPU: 2 UID: 0 PID: 0 Comm: swapper/2 Not tainted 6.17.0-rc5-g201825fb4278 #62 PREEMPT(voluntary)\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014\nRIP: 0010:tcp_retransmit_timer (net/ipv4/tcp_timer.c:542 (discriminator 7))\nCode: 41 55 41 54 55 53 48 8b af b8 08 00 00 48 89 fb 48 85 ed 0f 84 55 01 00 00 0f b6 47 12 3c 03 74 0c 0f b6 47 12 3c 04 74 04 90 <0f> 0b 90 48 8b 85 c0 00 00 00 48 89 ef 48 8b 40 30 e8 6a 4f 06 3e\nRSP: 0018:ffffc900002f8d40 EFLAGS: 00010293\nRAX: 0000000000000002 RBX: ffff888106911400 RCX: 0000000000000017\nRDX: 0000000002517619 RSI: ffffffff83764080 RDI: ffff888106911400\nRBP: ffff888106d5c000 R08: 0000000000000001 R09: ffffc900002f8de8\nR10: 00000000000000c2 R11: ffffc900002f8ff8 R12: ffff888106911540\nR13: ffff888106911480 R14: ffff888106911840 R15: ffffc900002f8de0\nFS: 0000000000000000(0000) GS:ffff88907b768000(0000) knlGS:0000000000000000\nCS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\nCR2: 00007f8044d69d90 CR3: 0000000002c30003 CR4: 0000000000370ef0\nCall Trace:\n <IRQ>\n tcp_write_timer (net/ipv4/tcp_timer.c:738)\n call_timer_fn (kernel/time/timer.c:1747)\n __run_timers (kernel/time/timer.c:1799 kernel/time/timer.c:2372)\n timer_expire_remote (kernel/time/timer.c:2385 kernel/time/timer.c:2376 kernel/time/timer.c:2135)\n tmigr_handle_remote_up (kernel/time/timer_migration.c:944 kernel/time/timer_migration.c:1035)\n __walk_groups.isra.0 (kernel/time/timer_migration.c:533 (discriminator 1))\n tmigr_handle_remote (kernel/time/timer_migration.c:1096)\n handle_softirqs (./arch/x86/include/asm/jump_label.h:36 ./include/trace/events/irq.h:142 kernel/softirq.c:580)\n irq_exit_rcu (kernel/softirq.c:614 kernel/softirq.c:453 kernel/softirq.c:680 kernel/softirq.c:696)\n sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1050 (discriminator 35) arch/x86/kernel/apic/apic.c:1050 (discriminator 35))\n </IRQ>"}], "id": "CVE-2025-39955", "lastModified": "2025-10-09T10:15:36.220", "metrics": {}, "published": "2025-10-09T10:15:36.220", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/17d699727577814198d744d6afe54735c6b54c99"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/33a4fdf0b4a25f8ce65380c3b0136b407ca57609"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/45c8a6cc2bcd780e634a6ba8e46bffbdf1fc5c01"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/7ec092a91ff351dcde89c23e795b73a328274db6"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/a4378dedd6e07e62f2fccb17d78c9665718763d0"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/ae313d14b45eca7a6bb29cb9bf396d977e7d28fb"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/dfd06131107e7b699ef1e2a24ed2f7d17c917753"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/fa4749c065644af4db496b338452a69a3e5147d9"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{}

{"created": "2025-10-09T12:51:10.683077+00:00", "updated": "2025-10-09T12:51:10.683101+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}