{"cve":"CVE-2023-52577","nvd":{"published":"2024-03-02T22:15:49.537","modified":"2026-06-17T06:43:04.043","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ndccp: fix dccp_v4_err()/dccp_v6_err() again\n\ndh->dccph_x is the 9th byte (offset 8) in \"struct dccp_hdr\",\nnot in the \"byte 7\" as Jann claimed.\n\nWe need to make sure the ICMP messages are big enough,\nusing more standard ways (no more assumptions).\n\nsyzbot reported:\nBUG: KMSAN: uninit-value in pskb_may_pull_reason include/linux/skbuff.h:2667 [inline]\nBUG: KMSAN: uninit-value in pskb_may_pull include/linux/skbuff.h:2681 [inline]\nBUG: KMSAN: uninit-value in dccp_v6_err+0x426/0x1aa0 net/dccp/ipv6.c:94\npskb_may_pull_reason include/linux/skbuff.h:2667 [inline]\npskb_may_pull include/linux/skbuff.h:2681 [inline]\ndccp_v6_err+0x426/0x1aa0 net/dccp/ipv6.c:94\nicmpv6_notify+0x4c7/0x880 net/ipv6/icmp.c:867\nicmpv6_rcv+0x19d5/0x30d0\nip6_protocol_deliver_rcu+0xda6/0x2a60 net/ipv6/ip6_input.c:438\nip6_input_finish net/ipv6/ip6_input.c:483 [inline]\nNF_HOOK include/linux/netfilter.h:304 [inline]\nip6_input+0x15d/0x430 net/ipv6/ip6_input.c:492\nip6_mc_input+0xa7e/0xc80 net/ipv6/ip6_input.c:586\ndst_input include/net/dst.h:468 [inline]\nip6_rcv_finish+0x5db/0x870 net/ipv6/ip6_input.c:79\nNF_HOOK include/linux/netfilter.h:304 [inline]\nipv6_rcv+0xda/0x390 net/ipv6/ip6_input.c:310\n__netif_receive_skb_one_core net/core/dev.c:5523 [inline]\n__netif_receive_skb+0x1a6/0x5a0 net/core/dev.c:5637\nnetif_receive_skb_internal net/core/dev.c:5723 [inline]\nnetif_receive_skb+0x58/0x660 net/core/dev.c:5782\ntun_rx_batched+0x83b/0x920\ntun_get_user+0x564c/0x6940 drivers/net/tun.c:2002\ntun_chr_write_iter+0x3af/0x5d0 drivers/net/tun.c:2048\ncall_write_iter include/linux/fs.h:1985 [inline]\nnew_sync_write fs/read_write.c:491 [inline]\nvfs_write+0x8ef/0x15c0 fs/read_write.c:584\nksys_write+0x20f/0x4c0 fs/read_write.c:637\n__do_sys_write fs/read_write.c:649 [inline]\n__se_sys_write fs/read_write.c:646 [inline]\n__x64_sys_write+0x93/0xd0 fs/read_write.c:646\ndo_syscall_x64 arch/x86/entry/common.c:50 [inline]\ndo_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80\nentry_SYSCALL_64_after_hwframe+0x63/0xcd\n\nUninit was created at:\nslab_post_alloc_hook+0x12f/0xb70 mm/slab.h:767\nslab_alloc_node mm/slub.c:3478 [inline]\nkmem_cache_alloc_node+0x577/0xa80 mm/slub.c:3523\nkmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:559\n__alloc_skb+0x318/0x740 net/core/skbuff.c:650\nalloc_skb include/linux/skbuff.h:1286 [inline]\nalloc_skb_with_frags+0xc8/0xbd0 net/core/skbuff.c:6313\nsock_alloc_send_pskb+0xa80/0xbf0 net/core/sock.c:2795\ntun_alloc_skb drivers/net/tun.c:1531 [inline]\ntun_get_user+0x23cf/0x6940 drivers/net/tun.c:1846\ntun_chr_write_iter+0x3af/0x5d0 drivers/net/tun.c:2048\ncall_write_iter include/linux/fs.h:1985 [inline]\nnew_sync_write fs/read_write.c:491 [inline]\nvfs_write+0x8ef/0x15c0 fs/read_write.c:584\nksys_write+0x20f/0x4c0 fs/read_write.c:637\n__do_sys_write fs/read_write.c:649 [inline]\n__se_sys_write fs/read_write.c:646 [inline]\n__x64_sys_write+0x93/0xd0 fs/read_write.c:646\ndo_syscall_x64 arch/x86/entry/common.c:50 [inline]\ndo_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80\nentry_SYSCALL_64_after_hwframe+0x63/0xcd\n\nCPU: 0 PID: 4995 Comm: syz-executor153 Not tainted 6.6.0-rc1-syzkaller-00014-ga747acc0b752 #0\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/04/2023","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-908"],"references":["https://git.kernel.org/stable/c/1512d8f45d3c5d0b5baa00bd8e600492fa569f40","https://git.kernel.org/stable/c/26df9ab5de308caa1503d937533c56c35793018d","https://git.kernel.org/stable/c/4600beae416d754a3cedbb1ecea8181ec05073b6","https://git.kernel.org/stable/c/60d73c62e3e4464f375758b6f2459c13d46465b6","https://git.kernel.org/stable/c/62c218124fe58372e0e1f60d5b634d21c264b337"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:46:54.846886191+00:00"},"epss":{"cve":"CVE-2023-52577","score":0.00229,"percentile":0.13721,"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."]}