dccp: fix dccp_v4_err()/dccp_v6_err() again
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Partial Red Hat: 2 without a fix
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-908 and the CVSS impact.
Summary
In the Linux kernel, the following vulnerability has been resolved: dccp: fix dccp_v4_err()/dccp_v6_err() again dh->dccph_x is the 9th byte (offset 8) in "struct dccp_hdr", not in the "byte 7" as Jann claimed. We need to make sure the ICMP messages are big enough, using more standard ways (no more assumptions). syzbot reported: BUG: KMSAN: uninit-value in pskb_may_pull_reason include/linux/skbuff.h:2667 [inline] BUG: KMSAN: uninit-value in pskb_may_pull include/linux/skbuff.h:2681 [inline] BUG: KMSAN: uninit-value in dccp_v6_err+0x426/0x1aa0 net/dccp/ipv6.c:94 pskb_may_pull_reason include/linux/skbuff.h:2667 [inline] pskb_may_pull include/linux/skbuff.h:2681 [inline] dccp_v6_err+0x426/0x1aa0 net/dccp/ipv6.c:94 icmpv6_notify+0x4c7/0x880 net/ipv6/icmp.c:867 icmpv6_rcv+0x19d5/0x30d0 ip6_protocol_deliver_rcu+0xda6/0x2a60 net/ipv6/ip6_input.c:438 ip6_input_finish net/ipv6/ip6_input.c:483 [inline] NF_HOOK include/linux/netfilter.h:304 [inline] ip6_input+0x15d/0x430 net/ipv6/ip6_input.c:492 ip6_mc_input+0xa7e/0xc80 net/ipv6/ip6_input.c:586 dst_input include/net/dst.h:468 [inline] ip6_rcv_finish+0x5db/0x870 net/ipv6/ip6_input.c:79 NF_HOOK include/linux/netfilter.h:304 [inline] ipv6_rcv+0xda/0x390 net/ipv6/ip6_input.c:310 __netif_receive_skb_one_core net/core/dev.c:5523 [inline] __netif_receive_skb+0x1a6/0x5a0 net/core/dev.c:5637 netif_receive_skb_internal net/core/dev.c:5723 [inline] netif_receive_skb+0x58/0x660 net/core/dev.c:5782 tun_rx_batched+0x83b/0x920 tun_get_user+0x564c/0x6940 drivers/net/tun.c:2002 tun_chr_write_iter+0x3af/0x5d0 drivers/net/tun.c:2048 call_write_iter include/linux/fs.h:1985 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x8ef/0x15c0 fs/read_write.c:584 ksys_write+0x20f/0x4c0 fs/read_write.c:637 __do_sys_write fs/read_write.c:649 [inline] __se_sys_write fs/read_write.c:646 [inline] __x64_sys_write+0x93/0xd0 fs/read_write.c:646 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Uninit was created at: slab_post_alloc_hook+0x12f/0xb70 mm/slab.h:767 slab_alloc_node mm/slub.c:3478 [inline] kmem_cache_alloc_node+0x577/0xa80 mm/slub.c:3523 kmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:559 __alloc_skb+0x318/0x740 net/core/skbuff.c:650 alloc_skb include/linux/skbuff.h:1286 [inline] alloc_skb_with_frags+0xc8/0xbd0 net/core/skbuff.c:6313 sock_alloc_send_pskb+0xa80/0xbf0 net/core/sock.c:2795 tun_alloc_skb drivers/net/tun.c:1531 [inline] tun_get_user+0x23cf/0x6940 drivers/net/tun.c:1846 tun_chr_write_iter+0x3af/0x5d0 drivers/net/tun.c:2048 call_write_iter include/linux/fs.h:1985 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x8ef/0x15c0 fs/read_write.c:584 ksys_write+0x20f/0x4c0 fs/read_write.c:637 __do_sys_write fs/read_write.c:649 [inline] __se_sys_write fs/read_write.c:646 [inline] __x64_sys_write+0x93/0xd0 fs/read_write.c:646 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd CPU: 0 PID: 4995 Comm: syz-executor153 Not tainted 6.6.0-rc1-syzkaller-00014-ga747acc0b752 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/04/2023
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 6.4.16 to before 6.5 | 6.5 | Patch available | CNA |
| Linux | Linux | 4.14.326 to before 4.14.327; 4.19.295 to before 4.19.296; 5.4.257 to before 5.4.258; 5.10.195 to before 5.10.198; 5.15.132 to before 5.15.134; 6.1.53 to before 6.1.56; 6.5.3 to before 6.5.6 | 4.14.327, 4.19.296, 5.4.258, 5.10.198, 5.15.134, 6.1.56, 6.5.6 | Patch available | CNA |
- Linux VendorLinux Affected 6.4.16 to before 6.5 Fixed in 6.5 Patch available CNA
- Linux VendorLinux Affected 4.14.326 to before 4.14.327; 4.19.295 to before 4.19.296; 5.4.257 to before 5.4.258; 5.10.195 to before 5.10.198; 5.15.132 to before 5.15.134; 6.1.53 to before 6.1.56; 6.5.3 to before 6.5.6 Fixed in 4.14.327, 4.19.296, 5.4.258, 5.10.198, 5.15.134, 6.1.56, 6.5.6 Patch available CNA
CPE configurations NVD · 4
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 5.10.195 to before 5.10.198; 5.15.132 to before 5.15.134; 6.1.53 to before 6.1.56; 6.5.3 to before 6.5.6 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:4.14.326:*:*:*:*:*:*:* | 4.14.326 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:4.19.295:*:*:*:*:*:*:* | 4.19.295 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:5.4.257:*:*:*:*:*:*:* | 5.4.257 | Vulnerable | Linux |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 5.10.195 to before 5.10.198; 5.15.132 to before 5.15.134; 6.1.53 to before 6.1.56; 6.5.3 to before 6.5.6 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:4.14.326:*:*:*:*:*:*:* Versions 4.14.326 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:4.19.295:*:*:*:*:*:*:* Versions 4.19.295 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:5.4.257:*:*:*:*:*:*:* Versions 5.4.257 Vulnerable ·Linux
Remediation
- Fix · CNA Linux (Linux) Fixed in 6.5
- Fix · CNA Linux (Linux) Fixed in 4.14.327, 4.19.296, 5.4.258, 5.10.198, 5.15.134, 6.1.56, 6.5.6
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 7 | Affected | No fix planned: Out of support scope |
Not affected: 2 products
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
Timeline
- 2026-10-02 Threatist record created from CVE-2023-52577
- 2026-10-03 Alias added: GHSA-85v9-53x3-q4xp
References
Patch 8
- https://git.kernel.org/stable/c/4600beae416d754a3cedbb1ecea8181ec05073b6
- https://git.kernel.org/stable/c/62c218124fe58372e0e1f60d5b634d21c264b337
- https://git.kernel.org/stable/c/a6f4d582e25d512c9b492670b6608436694357b3
- https://git.kernel.org/stable/c/60d73c62e3e4464f375758b6f2459c13d46465b6
- https://git.kernel.org/stable/c/26df9ab5de308caa1503d937533c56c35793018d
- https://git.kernel.org/stable/c/73be49248a04746096339a48a33fa2f03bd85969
- https://git.kernel.org/stable/c/1512d8f45d3c5d0b5baa00bd8e600492fa569f40
- https://git.kernel.org/stable/c/6af289746a636f71f4c0535a9801774118486c7a
More Linux Kernel vulnerabilities
- TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
- TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
- TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
- TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
- TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
Sources
- CVE-2023-52577 · CVE Program
- CVE-2023-52577 · NVD
- FIRST EPSS
- GHSA-85v9-53x3-q4xp · GitHub Advisory Database · CC BY 4.0
- CVE-2023-52577 · Red Hat security data · CC BY 4.0
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