Answer in brief
CVE-2024-36904 records a Unknown severity vulnerability in tcp: Use refcount_inc_not_zero() in tcp_twsk_unique().. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic), Siemens/RUGGEDCOM RST2428P (generic), Siemens/SCALANCE XCM-/XRM-/XCH-/XRH-300 family (generic) and additional mapped packages. Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
Answer in brief
CVE-2024-36904 records a Unknown severity vulnerability in tcp: Use refcount_inc_not_zero() in tcp_twsk_unique().. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic), Siemens/RUGGEDCOM RST2428P (generic), Siemens/SCALANCE XCM-/XRM-/XCH-/XRH-300 family (generic) and additional mapped packages. Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic), Siemens/RUGGEDCOM RST2428P (generic), Siemens/SCALANCE XCM-/XRM-/XCH-/XRH-300 family (generic) and additional mapped packages. Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=ec94c2696f0bcd5ae92a553244e4ac30d2171a2d <84546cc1aeeb4df3e444b18a4293c9823f974be9 || >=ec94c2696f0bcd5ae92a553244e4ac30d2171a2d <1796ca9c6f5bd50554214053af5f47d112818ee3 || >=ec94c2696f0bcd5ae92a553244e4ac30d2171a2d <1d9cf07810c30ef7948879567d10fd1f01121d34 || >=ec94c2696f0bcd5ae92a553244e4ac30d2171a2d <27b0284d8be182a81feb65581ab6a724dfd596e8 || >=ec94c2696f0bcd5ae92a553244e4ac30d2171a2d <13ed7cdf079686ccd3618335205700c03f6fb446 || >=ec94c2696f0bcd5ae92a553244e4ac30d2171a2d <6e48faad92be13166184d21506e4e54c79c13adc || >=ec94c2696f0bcd5ae92a553244e4ac30d2171a2d <517e32ea0a8c72202d0d8aa8df50a7cd3d6fdefc || >=ec94c2696f0bcd5ae92a553244e4ac30d2171a2d <f2db7230f73a80dbb179deab78f88a7947f0ab7e | 84546cc1aeeb4df3e444b18a4293c9823f974be9, 1796ca9c6f5bd50554214053af5f47d112818ee3, 1d9cf07810c30ef7948879567d10fd1f01121d34, 27b0284d8be182a81feb65581ab6a724dfd596e8, 13ed7cdf079686ccd3618335205700c03f6fb446, 6e48faad92be13166184d21506e4e54c79c13adc, 517e32ea0a8c72202d0d8aa8df50a7cd3d6fdefc, f2db7230f73a80dbb179deab78f88a7947f0ab7e |
| Linux/Linuxgeneric | 4.16 | Not reported |
| Siemens/RUGGEDCOM RST2428Pgeneric | >=0 <V3.1 | V3.1 |
| Siemens/SCALANCE XCM-/XRM-/XCH-/XRH-300 familygeneric | >=0 <V3.1 | V3.1 |
| Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.0 <V3.1.5 | V3.1.5 |
| Siemens/SIMATIC S7-1500 CPU 1518F-4 PN/DP MFPgeneric | >=V3.1.0 <V3.1.5 | V3.1.5 |
| Siemens/SIMATIC S7-1500 TM MFP - GNU/Linux subsystemgeneric | >=0 <* | * |
| Siemens/SIPLUS S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.0 <V3.1.5 | V3.1.5 |
Published upstream
May 30, 2024
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 5, 2026
In the Linux kernel, the following vulnerability has been resolved: tcp: Use refcount_inc_not_zero() in tcp_twsk_unique(). Anderson Nascimento reported a use-after-free splat in tcp_twsk_unique() with nice analysis. Since commit ec94c2696f0b ("tcp/dccp: avoid one atomic operation for timewait hashdance"), inet_twsk_hashdance() sets TIME-WAIT socket's sk_refcnt after putting it into ehash and releasing the bucket lock. Thus, there is a small race window where other threads could try to reuse the port during connect() and call sock_hold() in tcp_twsk_unique() for the TIME-WAIT socket with zero refcnt. If that happens, the refcnt taken by tcp_twsk_unique() is overwritten and sock_put() will cause underflow, triggering a real use-after-free somewhere else. To avoid the use-after-free, we need to use refcount_inc_not_zero() in tcp_twsk_unique() and give up on reusing the port if it returns false. [0]: refcount_t: addition on 0; use-after-free. WARNING: CPU: 0 PID: 1039313 at lib/refcount.c:25 refcount_warn_saturate+0xe5/0x110 CPU: 0 PID: 1039313 Comm: trigger Not tainted 6.8.6-200.fc39.x86_64 #1 Hardware name: VMware, Inc. VMware20,1/440BX Desktop Reference Platform, BIOS VMW201.00V.21805430.B64.2305221830 05/22/2023 RIP: 0010:refcount_warn_saturate+0xe5/0x110 Code: 42 8e ff 0f 0b c3 cc cc cc cc 80 3d aa 13 ea 01 00 0f 85 5e ff ff ff 48 c7 c7 f8 8e b7 82 c6 05 96 13 ea 01 01 e8 7b 42 8e ff <0f> 0b c3 cc cc cc cc 48 c7 c7 50 8f b7 82 c6 05 7a 13 ea 01 01 e8 RSP: 0018:ffffc90006b43b60 EFLAGS: 00010282 RAX: 0000000000000000 RBX: ffff888009bb3ef0 RCX: 0000000000000027 RDX: ffff88807be218c8 RSI: 0000000000000001 RDI: ffff88807be218c0 RBP: 0000000000069d70 R08: 0000000000000000 R09: ffffc90006b439f0 R10: ffffc90006b439e8 R11: 0000000000000003 R12: ffff8880029ede84 R13: 0000000000004e20 R14: ffffffff84356dc0 R15: ffff888009bb3ef0 FS: 00007f62c10926c0(0000) GS:ffff88807be00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020ccb000 CR3: 000000004628c005 CR4: 0000000000f70ef0 PKRU: 55555554 Call Trace: <TASK> ? refcount_warn_saturate+0xe5/0x110 ? __warn+0x81/0x130 ? refcount_warn_saturate+0xe5/0x110 ? report_bug+0x171/0x1a0 ? refcount_warn_saturate+0xe5/0x110 ? handle_bug+0x3c/0x80 ? exc_invalid_op+0x17/0x70 ? asm_exc_invalid_op+0x1a/0x20 ? refcount_warn_saturate+0xe5/0x110 tcp_twsk_unique+0x186/0x190 __inet_check_established+0x176/0x2d0 __inet_hash_connect+0x74/0x7d0 ? __pfx___inet_check_established+0x10/0x10 tcp_v4_connect+0x278/0x530 __inet_stream_connect+0x10f/0x3d0 inet_stream_connect+0x3a/0x60 __sys_connect+0xa8/0xd0 __x64_sys_connect+0x18/0x20 do_syscall_64+0x83/0x170 entry_SYSCALL_64_after_hwframe+0x78/0x80 RIP: 0033:0x7f62c11a885d Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d a3 45 0c 00 f7 d8 64 89 01 48 RSP: 002b:00007f62c1091e58 EFLAGS: 00000296 ORIG_RAX: 000000000000002a RAX: ffffffffffffffda RBX: 0000000020ccb004 RCX: 00007f62c11a885d RDX: 0000000000000010 RSI: 0000000020ccb000 RDI: 0000000000000003 RBP: 00007f62c1091e90 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000296 R12: 00007f62c10926c0 R13: ffffffffffffff88 R14: 0000000000000000 R15: 00007ffe237885b0 </TASK>
Quoted source text, attributed separately from HOL analysis.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic), Siemens/RUGGEDCOM RST2428P (generic), Siemens/SCALANCE XCM-/XRM-/XCH-/XRH-300 family (generic) and additional mapped packages. Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=ec94c2696f0bcd5ae92a553244e4ac30d2171a2d <84546cc1aeeb4df3e444b18a4293c9823f974be9 || >=ec94c2696f0bcd5ae92a553244e4ac30d2171a2d <1796ca9c6f5bd50554214053af5f47d112818ee3 || >=ec94c2696f0bcd5ae92a553244e4ac30d2171a2d <1d9cf07810c30ef7948879567d10fd1f01121d34 || >=ec94c2696f0bcd5ae92a553244e4ac30d2171a2d <27b0284d8be182a81feb65581ab6a724dfd596e8 || >=ec94c2696f0bcd5ae92a553244e4ac30d2171a2d <13ed7cdf079686ccd3618335205700c03f6fb446 || >=ec94c2696f0bcd5ae92a553244e4ac30d2171a2d <6e48faad92be13166184d21506e4e54c79c13adc || >=ec94c2696f0bcd5ae92a553244e4ac30d2171a2d <517e32ea0a8c72202d0d8aa8df50a7cd3d6fdefc || >=ec94c2696f0bcd5ae92a553244e4ac30d2171a2d <f2db7230f73a80dbb179deab78f88a7947f0ab7e | 84546cc1aeeb4df3e444b18a4293c9823f974be9, 1796ca9c6f5bd50554214053af5f47d112818ee3, 1d9cf07810c30ef7948879567d10fd1f01121d34, 27b0284d8be182a81feb65581ab6a724dfd596e8, 13ed7cdf079686ccd3618335205700c03f6fb446, 6e48faad92be13166184d21506e4e54c79c13adc, 517e32ea0a8c72202d0d8aa8df50a7cd3d6fdefc, f2db7230f73a80dbb179deab78f88a7947f0ab7e |
| Linux/Linuxgeneric | 4.16 | Not reported |
| Siemens/RUGGEDCOM RST2428Pgeneric | >=0 <V3.1 | V3.1 |
| Siemens/SCALANCE XCM-/XRM-/XCH-/XRH-300 familygeneric | >=0 <V3.1 | V3.1 |
| Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.0 <V3.1.5 | V3.1.5 |
| Siemens/SIMATIC S7-1500 CPU 1518F-4 PN/DP MFPgeneric | >=V3.1.0 <V3.1.5 | V3.1.5 |
| Siemens/SIMATIC S7-1500 TM MFP - GNU/Linux subsystemgeneric | >=0 <* | * |
| Siemens/SIPLUS S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.0 <V3.1.5 | V3.1.5 |
Published upstream
May 30, 2024
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 5, 2026
In the Linux kernel, the following vulnerability has been resolved: tcp: Use refcount_inc_not_zero() in tcp_twsk_unique(). Anderson Nascimento reported a use-after-free splat in tcp_twsk_unique() with nice analysis. Since commit ec94c2696f0b ("tcp/dccp: avoid one atomic operation for timewait hashdance"), inet_twsk_hashdance() sets TIME-WAIT socket's sk_refcnt after putting it into ehash and releasing the bucket lock. Thus, there is a small race window where other threads could try to reuse the port during connect() and call sock_hold() in tcp_twsk_unique() for the TIME-WAIT socket with zero refcnt. If that happens, the refcnt taken by tcp_twsk_unique() is overwritten and sock_put() will cause underflow, triggering a real use-after-free somewhere else. To avoid the use-after-free, we need to use refcount_inc_not_zero() in tcp_twsk_unique() and give up on reusing the port if it returns false. [0]: refcount_t: addition on 0; use-after-free. WARNING: CPU: 0 PID: 1039313 at lib/refcount.c:25 refcount_warn_saturate+0xe5/0x110 CPU: 0 PID: 1039313 Comm: trigger Not tainted 6.8.6-200.fc39.x86_64 #1 Hardware name: VMware, Inc. VMware20,1/440BX Desktop Reference Platform, BIOS VMW201.00V.21805430.B64.2305221830 05/22/2023 RIP: 0010:refcount_warn_saturate+0xe5/0x110 Code: 42 8e ff 0f 0b c3 cc cc cc cc 80 3d aa 13 ea 01 00 0f 85 5e ff ff ff 48 c7 c7 f8 8e b7 82 c6 05 96 13 ea 01 01 e8 7b 42 8e ff <0f> 0b c3 cc cc cc cc 48 c7 c7 50 8f b7 82 c6 05 7a 13 ea 01 01 e8 RSP: 0018:ffffc90006b43b60 EFLAGS: 00010282 RAX: 0000000000000000 RBX: ffff888009bb3ef0 RCX: 0000000000000027 RDX: ffff88807be218c8 RSI: 0000000000000001 RDI: ffff88807be218c0 RBP: 0000000000069d70 R08: 0000000000000000 R09: ffffc90006b439f0 R10: ffffc90006b439e8 R11: 0000000000000003 R12: ffff8880029ede84 R13: 0000000000004e20 R14: ffffffff84356dc0 R15: ffff888009bb3ef0 FS: 00007f62c10926c0(0000) GS:ffff88807be00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020ccb000 CR3: 000000004628c005 CR4: 0000000000f70ef0 PKRU: 55555554 Call Trace: <TASK> ? refcount_warn_saturate+0xe5/0x110 ? __warn+0x81/0x130 ? refcount_warn_saturate+0xe5/0x110 ? report_bug+0x171/0x1a0 ? refcount_warn_saturate+0xe5/0x110 ? handle_bug+0x3c/0x80 ? exc_invalid_op+0x17/0x70 ? asm_exc_invalid_op+0x1a/0x20 ? refcount_warn_saturate+0xe5/0x110 tcp_twsk_unique+0x186/0x190 __inet_check_established+0x176/0x2d0 __inet_hash_connect+0x74/0x7d0 ? __pfx___inet_check_established+0x10/0x10 tcp_v4_connect+0x278/0x530 __inet_stream_connect+0x10f/0x3d0 inet_stream_connect+0x3a/0x60 __sys_connect+0xa8/0xd0 __x64_sys_connect+0x18/0x20 do_syscall_64+0x83/0x170 entry_SYSCALL_64_after_hwframe+0x78/0x80 RIP: 0033:0x7f62c11a885d Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d a3 45 0c 00 f7 d8 64 89 01 48 RSP: 002b:00007f62c1091e58 EFLAGS: 00000296 ORIG_RAX: 000000000000002a RAX: ffffffffffffffda RBX: 0000000020ccb004 RCX: 00007f62c11a885d RDX: 0000000000000010 RSI: 0000000020ccb000 RDI: 0000000000000003 RBP: 00007f62c1091e90 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000296 R12: 00007f62c10926c0 R13: ffffffffffffff88 R14: 0000000000000000 R15: 00007ffe237885b0 </TASK>
Quoted source text, attributed separately from HOL analysis.