{"cve":"CVE-2021-47014","nvd":{"published":"2024-02-28T09:15:38.860","modified":"2026-08-04T10:16:41.750","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: act_ct: fix wild memory access when clearing fragments\n\nwhile testing re-assembly/re-fragmentation using act_ct, it's possible to\nobserve a crash like the following one:\n\n KASAN: maybe wild-memory-access in range [0x0001000000000448-0x000100000000044f]\n CPU: 50 PID: 0 Comm: swapper/50 Tainted: G S                5.12.0-rc7+ #424\n Hardware name: Dell Inc. PowerEdge R730/072T6D, BIOS 2.4.3 01/17/2017\n RIP: 0010:inet_frag_rbtree_purge+0x50/0xc0\n Code: 00 fc ff df 48 89 c3 31 ed 48 89 df e8 a9 7a 38 ff 4c 89 fe 48 89 df 49 89 c6 e8 5b 3a 38 ff 48 8d 7b 40 48 89 f8 48 c1 e8 03 <42> 80 3c 20 00 75 59 48 8d bb d0 00 00 00 4c 8b 6b 40 48 89 f8 48\n RSP: 0018:ffff888c31449db8 EFLAGS: 00010203\n RAX: 0000200000000089 RBX: 000100000000040e RCX: ffffffff989eb960\n RDX: 0000000000000140 RSI: ffffffff97cfb977 RDI: 000100000000044e\n RBP: 0000000000000900 R08: 0000000000000000 R09: ffffed1186289350\n R10: 0000000000000003 R11: ffffed1186289350 R12: dffffc0000000000\n R13: 000100000000040e R14: 0000000000000000 R15: ffff888155e02160\n FS:  0000000000000000(0000) GS:ffff888c31440000(0000) knlGS:0000000000000000\n CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n CR2: 00005600cb70a5b8 CR3: 0000000a2c014005 CR4: 00000000003706e0\n DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000\n DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400\n Call Trace:\n  <IRQ>\n  inet_frag_destroy+0xa9/0x150\n  call_timer_fn+0x2d/0x180\n  run_timer_softirq+0x4fe/0xe70\n  __do_softirq+0x197/0x5a0\n  irq_exit_rcu+0x1de/0x200\n  sysvec_apic_timer_interrupt+0x6b/0x80\n  </IRQ>\n\nwhen act_ct temporarily stores an IP fragment, restoring the skb qdisc cb\nresults in putting random data in FRAG_CB(), and this causes those \"wild\"\nmemory accesses later, when the rbtree is purged. Never overwrite the skb\ncb in case tcf_ct_handle_fragments() returns -EINPROGRESS.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8},"cwes":["CWE-754"],"references":["https://git.kernel.org/stable/c/0648941f4c8bbf8b4b6c0b270889ae7aa769b921","https://git.kernel.org/stable/c/f77bd544a6bbe69aa50d9ed09f13494cf36ff806","https://git.kernel.org/stable/c/0648941f4c8bbf8b4b6c0b270889ae7aa769b921","https://git.kernel.org/stable/c/f77bd544a6bbe69aa50d9ed09f13494cf36ff806"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:45:59.823092188+00:00"},"epss":{"cve":"CVE-2021-47014","score":0.00235,"percentile":0.14462,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}