CVE-2026-45841
netfilter: nfnetlink_osf: fix divide-by-zero in OSF_WSS_MODULO
In the Linux kernel, the following vulnerability has been resolved: netfilter: nfnetlink_osf: fix divide-by-zero in OSF_WSS_MODULO nf_osf_match_one() computes ctx->window % f->wss.val in the OSF_WSS_MODULO branch with no guard for f->wss.val == 0. A CAP_NET_ADMIN user can add such a fingerprint via nfnetlink; a subsequent matching TCP SYN divides by zero and panics the kernel. Reject the bogus fingerprint in nfnl_osf_add_callback() above the per-option for-loop. f->wss is per-fingerprint, not per-option, so the check must run regardless of f->opt_num (including 0). Also reject wss.wc >= OSF_WSS_MAX; nf_osf_match_one() already treats that as "should not happen". Crash: Oops: divide error: 0000 [#1] SMP KASAN NOPTI RIP: 0010:nf_osf_match_one (net/netfilter/nfnetlink_osf.c:98) Call Trace: <IRQ> nf_osf_match (net/netfilter/nfnetlink_osf.c:220) xt_osf_match_packet (net/netfilter/xt_osf.c:32) ipt_do_table (net/ipv4/netfilter/ip_tables.c:348) nf_hook_slow (net/netfilter/core.c:622) ip_local_deliver (net/ipv4/ip_input.c:265) ip_rcv (include/linux/skbuff.h:1162) __netif_receive_skb_one_core (net/core/dev.c:6181) process_backlog (net/core/dev.c:6642) __napi_poll (net/core/dev.c:7710) net_rx_action (net/core/dev.c:7945) handle_softirqs (kernel/softirq.c:622)
Fixes and workarounds
No remediation reported in collected sources.
Missing remediation information is not evidence that no patch exists.
Affected products and versions
| Product | Versions | Authority |
|---|---|---|
| Linux Linux |
≥ 11eeef41d5f63c7d2f7fdfcc733eb7fb137cc384; < cb833bbc1b3c51e08652d3c86298307c07d3f2db (affected, git) ≥ 11eeef41d5f63c7d2f7fdfcc733eb7fb137cc384; < 26900306a5a2c3e4f75c643a064525526bb6e5f3 (affected, git) ≥ 11eeef41d5f63c7d2f7fdfcc733eb7fb137cc384; < 0694618cf3e9b120666e31f5f383a6e466d95a0d (affected, git) ≥ 11eeef41d5f63c7d2f7fdfcc733eb7fb137cc384; < 8def8fbd23f40e945febe913d04b731012ce0082 (affected, git) ≥ 11eeef41d5f63c7d2f7fdfcc733eb7fb137cc384; < c55940895245d8ef658ab381248a28755218d625 (affected, git) ≥ 11eeef41d5f63c7d2f7fdfcc733eb7fb137cc384; < fb965b1cfe92b28d28b5ebe3116b81dbef9f2d2f (affected, git) ≥ 11eeef41d5f63c7d2f7fdfcc733eb7fb137cc384; < 9a05e195618a6d474f2bcd5b6376d0ffc2f00366 (affected, git) ≥ 11eeef41d5f63c7d2f7fdfcc733eb7fb137cc384; < 2195574dc6d9017d32ac346987e12659f931d932 (affected, git) Other versions: unaffected |
CNA: Linux |
| Linux Linux |
2.6.31 (affected) ≥ 0; < 2.6.31 (unaffected, semver) ≥ 5.10.258; ≤ 5.10.* (unaffected, semver) ≥ 5.15.209; ≤ 5.15.* (unaffected, semver) ≥ 6.1.175; ≤ 6.1.* (unaffected, semver) ≥ 6.6.141; ≤ 6.6.* (unaffected, semver) ≥ 6.12.91; ≤ 6.12.* (unaffected, semver) ≥ 6.18.33; ≤ 6.18.* (unaffected, semver) ≥ 7.0.10; ≤ 7.0.* (unaffected, semver) ≥ 7.1; ≤ * (unaffected, original_commit_for_fix) Other versions: affected |
CNA: Linux |
| SIMATIC S7-1500 CPU 1518-4 PN/DP MFP Siemens |
≥ V3.1.6; < * (affected, custom)
Other versions: unknown |
ADP: siemens-SADP |
| SIMATIC S7-1500 CPU 1518-4 PN/DP MFP Siemens |
≥ V3.1.7; < * (affected, custom)
Other versions: unknown |
ADP: siemens-SADP |
| SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP Siemens |
≥ V3.1.6; < * (affected, custom)
Other versions: unknown |
ADP: siemens-SADP |
| SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP Siemens |
≥ V3.1.7; < * (affected, custom)
Other versions: unknown |
ADP: siemens-SADP |
| SIMATIC S7-1500 TM MFP - GNU/Linux subsystem Siemens |
≥ 0; < * (affected, custom)
Other versions: unknown |
ADP: siemens-SADP |
| SIPLUS S7-1500 CPU 1518-4 PN/DP MFP Siemens |
≥ V3.1.6; < * (affected, custom)
Other versions: unknown |
ADP: siemens-SADP |
| SIPLUS S7-1500 CPU 1518-4 PN/DP MFP Siemens |
≥ V3.1.7; < * (affected, custom)
Other versions: unknown |
ADP: siemens-SADP |
Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.
CVSS assessments
No CVSS assessment reported. An unscored record is not a low-severity determination.
Exploit evidence
No exploit evidence in collected sources. This is not proof of no exploitation.
References
- https://git.kernel.org/stable/c/cb833bbc1b3c51e08652d3c86298307c07d3f2dbCNA: Linux
- https://git.kernel.org/stable/c/26900306a5a2c3e4f75c643a064525526bb6e5f3CNA: Linux
- https://git.kernel.org/stable/c/0694618cf3e9b120666e31f5f383a6e466d95a0dCNA: Linux
- https://git.kernel.org/stable/c/8def8fbd23f40e945febe913d04b731012ce0082CNA: Linux
- https://git.kernel.org/stable/c/c55940895245d8ef658ab381248a28755218d625CNA: Linux
- https://git.kernel.org/stable/c/fb965b1cfe92b28d28b5ebe3116b81dbef9f2d2fCNA: Linux
- https://git.kernel.org/stable/c/9a05e195618a6d474f2bcd5b6376d0ffc2f00366CNA: Linux
- https://git.kernel.org/stable/c/2195574dc6d9017d32ac346987e12659f931d932CNA: Linux
- https://cert-portal.siemens.com/productcert/html/ssa-019113.htmlADP: siemens-SADP
- https://cert-portal.siemens.com/productcert/html/ssa-457936.htmlADP: siemens-SADP
- https://cert-portal.siemens.com/productcert/html/ssa-784472.htmlADP: siemens-SADP
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