{"id":"CVE-2023-53121","title":"tcp: tcp_make_synack() can be called from process context","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\ntcp: tcp_make_synack() can be called from process context\n\ntcp_rtx_synack() now could be called in process context as explained in\n0a375c822497 (\"tcp: tcp_rtx_synack() …","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 8336886f786fdacbc19b719c1f7ea91eb70706d4 < d493d4fe88195a144d6a277a90062a7534ed2192","Linux >= 8336886f786fdacbc19b719c1f7ea91eb70706d4 < e23ca307745be3df7fe9762f3e2a7e311a57852e","Linux >= 8336886f786fdacbc19b719c1f7ea91eb70706d4 < 442aa78ed70188b21ccd8669738448702c0a3281","Linux >= 8336886f786fdacbc19b719c1f7ea91eb70706d4 < 77ad58bca0119e8cc3e0e9d91a3f22caa66e4dfa","Linux >= 8336886f786fdacbc19b719c1f7ea91eb70706d4 < ad07290d63ff6689f50565b02f5b6f34ec15a5ca","Linux >= 8336886f786fdacbc19b719c1f7ea91eb70706d4 < 9180aa4622a720b433e842b4d3aa34d73eec577a","Linux >= 8336886f786fdacbc19b719c1f7ea91eb70706d4 < 7613cde8c0c1f02a7ec2e1d536c01b65b135fc1c","Linux >= 8336886f786fdacbc19b719c1f7ea91eb70706d4 < bced3f7db95ff2e6ca29dc4d1c9751ab5e736a09","Linux 3.7"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-11-05T20:18:11.326915Z"},"published":"2025-05-02","updated":"2026-11-05","sourceUpdated":"2026-11-05T20:21:02.884Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2023-53121","references":[{"url":"https://git.kernel.org/stable/c/d493d4fe88195a144d6a277a90062a7534ed2192"},{"url":"https://git.kernel.org/stable/c/e23ca307745be3df7fe9762f3e2a7e311a57852e"},{"url":"https://git.kernel.org/stable/c/442aa78ed70188b21ccd8669738448702c0a3281"},{"url":"https://git.kernel.org/stable/c/77ad58bca0119e8cc3e0e9d91a3f22caa66e4dfa"},{"url":"https://git.kernel.org/stable/c/ad07290d63ff6689f50565b02f5b6f34ec15a5ca"},{"url":"https://git.kernel.org/stable/c/9180aa4622a720b433e842b4d3aa34d73eec577a"},{"url":"https://git.kernel.org/stable/c/7613cde8c0c1f02a7ec2e1d536c01b65b135fc1c"},{"url":"https://git.kernel.org/stable/c/bced3f7db95ff2e6ca29dc4d1c9751ab5e736a09"}],"tags":["cve.org"],"epss":0.00189,"epssPercentile":0.08523,"ingestedAt":"2026-11-05T22:38:31.774Z","slug":"CVE-2023-53121","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\ntcp: tcp_make_synack() can be called from process context\n\ntcp_rtx_synack() now could be called in process context as explained in\n0a375c822497 (\"tcp: tcp_rtx_synack() can be called from process\ncontext\").\n\ntcp_rtx_synack() might call tcp_make_synack(), which will touch per-CPU\nvariables with preemption enabled. This causes the following BUG:\n\n    BUG: using __this_cpu_add() in preemptible [00000000] code: ThriftIO1/5464\n    caller is tcp_make_synack+0x841/0xac0\n    Call Trace:\n     <TASK>\n     dump_stack_lvl+0x10d/0x1a0\n     check_preemption_disabled+0x104/0x110\n     tcp_make_synack+0x841/0xac0\n     tcp_v6_send_synack+0x5c/0x450\n     tcp_rtx_synack+0xeb/0x1f0\n     inet_rtx_syn_ack+0x34/0x60\n     tcp_check_req+0x3af/0x9e0\n     tcp_rcv_state_process+0x59b/0x2030\n     tcp_v6_do_rcv+0x5f5/0x700\n     release_sock+0x3a/0xf0\n     tcp_sendmsg+0x33/0x40\n     ____sys_sendmsg+0x2f2/0x490\n     __sys_sendmsg+0x184/0x230\n     do_syscall_64+0x3d/0x90\n\nAvoid calling __TCP_INC_STATS() with will touch per-cpu variables. Use\nTCP_INC_STATS() which is safe to be called from context switch.\n\n## Affected\n\n- `Linux >= 8336886f786fdacbc19b719c1f7ea91eb70706d4 < d493d4fe88195a144d6a277a90062a7534ed2192`\n- `Linux >= 8336886f786fdacbc19b719c1f7ea91eb70706d4 < e23ca307745be3df7fe9762f3e2a7e311a57852e`\n- `Linux >= 8336886f786fdacbc19b719c1f7ea91eb70706d4 < 442aa78ed70188b21ccd8669738448702c0a3281`\n- `Linux >= 8336886f786fdacbc19b719c1f7ea91eb70706d4 < 77ad58bca0119e8cc3e0e9d91a3f22caa66e4dfa`\n- `Linux >= 8336886f786fdacbc19b719c1f7ea91eb70706d4 < ad07290d63ff6689f50565b02f5b6f34ec15a5ca`\n- `Linux >= 8336886f786fdacbc19b719c1f7ea91eb70706d4 < 9180aa4622a720b433e842b4d3aa34d73eec577a`\n- `Linux >= 8336886f786fdacbc19b719c1f7ea91eb70706d4 < 7613cde8c0c1f02a7ec2e1d536c01b65b135fc1c`\n- `Linux >= 8336886f786fdacbc19b719c1f7ea91eb70706d4 < bced3f7db95ff2e6ca29dc4d1c9751ab5e736a09`\n- `Linux 3.7`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}