--- id: CVE-2023-53204 title: 'af_unix: Fix data-races around user->unix_inflight.' summary: |- In the Linux kernel, the following vulnerability has been resolved: af_unix: Fix data-races around user->unix_inflight. user->unix_inflight is changed under spin_lock(unix_gc_lock), but too_many_unix_fds() reads it locklessly. Let's a… severity: none vendor: Linux product: Linux affected: - >- Linux >= 712f4aad406bb1ed67f3f98d04c044191f0ff593 < df97b5ea9f3ac9308c3a633524dab382cd59d9e5 - >- Linux >= 712f4aad406bb1ed67f3f98d04c044191f0ff593 < 03d133dfbcec9d439729cc64706c7eb6d1663a24 - >- Linux >= 712f4aad406bb1ed67f3f98d04c044191f0ff593 < adcf4e069358cdee8593663650ea447215a1c49e - >- Linux >= 712f4aad406bb1ed67f3f98d04c044191f0ff593 < b401d7e485b0a234cf8fe9a6ae99dbcd20863138 - >- Linux >= 712f4aad406bb1ed67f3f98d04c044191f0ff593 < 9151ed4b006125cba7c06c79df504340ea4e9386 - >- Linux >= 712f4aad406bb1ed67f3f98d04c044191f0ff593 < b9cdbb38e030fc2fe97fe27b54cbb6b4fbff250f - >- Linux >= 712f4aad406bb1ed67f3f98d04c044191f0ff593 < ac92f239a079678a035c0faad9089354a874aede - >- Linux >= 712f4aad406bb1ed67f3f98d04c044191f0ff593 < 0bc36c0650b21df36fbec8136add83936eaf0607 - Linux a5a6cf8c405e826ff7ed1308dde72560c0ed4854 - Linux df87da0783c4492b944badfea9d5c3c56b834697 - Linux 3d024dcef2548028e9f9b7876a544e6e0af00175 - Linux aa51d1c24ec3b6605f7cc7ef500c96cd71d7ef90 - Linux a5b9e44af8d3edaf49d14a91cc519a9fba439e67 - Linux dc6b0ec667f67d4768e72c1b7f1bbc14ea52379c - Linux 9b8b611fe0f86f07a4ff4a5f3bcb0ea7ceb7da3b - Linux 5e226f9689d90ad8ab21b4a969ae3058777f0aff - Linux >= 3.2.78 < 3.3 - Linux >= 3.10.96 < 3.11 - Linux >= 3.12.57 < 3.13 - Linux >= 3.14.60 < 3.15 - Linux >= 3.18.27 < 3.19 - Linux >= 4.1.17 < 4.2 - Linux >= 4.3.5 < 4.4 - Linux >= 4.4.1 < 4.5 - Linux 4.5 ssvc: exploitation: none automatable: 'no' technicalImpact: partial timestamp: '2026-11-05T20:20:30.750540Z' published: '2025-09-15' updated: '2026-11-05' sourceUpdated: '2026-11-05T20:21:07.602Z' source: CVEORG sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2023-53204' references: - url: 'https://git.kernel.org/stable/c/df97b5ea9f3ac9308c3a633524dab382cd59d9e5' - url: 'https://git.kernel.org/stable/c/03d133dfbcec9d439729cc64706c7eb6d1663a24' - url: 'https://git.kernel.org/stable/c/adcf4e069358cdee8593663650ea447215a1c49e' - url: 'https://git.kernel.org/stable/c/b401d7e485b0a234cf8fe9a6ae99dbcd20863138' - url: 'https://git.kernel.org/stable/c/9151ed4b006125cba7c06c79df504340ea4e9386' - url: 'https://git.kernel.org/stable/c/b9cdbb38e030fc2fe97fe27b54cbb6b4fbff250f' - url: 'https://git.kernel.org/stable/c/ac92f239a079678a035c0faad9089354a874aede' - url: 'https://git.kernel.org/stable/c/0bc36c0650b21df36fbec8136add83936eaf0607' tags: - cve.org epss: 0.00119 epssPercentile: 0.01779 ingestedAt: '2026-11-05T22:38:31.787Z' --- ## Overview In the Linux kernel, the following vulnerability has been resolved: af_unix: Fix data-races around user->unix_inflight. user->unix_inflight is changed under spin_lock(unix_gc_lock), but too_many_unix_fds() reads it locklessly. Let's annotate the write/read accesses to user->unix_inflight. BUG: KCSAN: data-race in unix_attach_fds / unix_inflight write to 0xffffffff8546f2d0 of 8 bytes by task 44798 on cpu 1: unix_inflight+0x157/0x180 net/unix/scm.c:66 unix_attach_fds+0x147/0x1e0 net/unix/scm.c:123 unix_scm_to_skb net/unix/af_unix.c:1827 [inline] unix_dgram_sendmsg+0x46a/0x14f0 net/unix/af_unix.c:1950 unix_seqpacket_sendmsg net/unix/af_unix.c:2308 [inline] unix_seqpacket_sendmsg+0xba/0x130 net/unix/af_unix.c:2292 sock_sendmsg_nosec net/socket.c:725 [inline] sock_sendmsg+0x148/0x160 net/socket.c:748 ____sys_sendmsg+0x4e4/0x610 net/socket.c:2494 ___sys_sendmsg+0xc6/0x140 net/socket.c:2548 __sys_sendmsg+0x94/0x140 net/socket.c:2577 __do_sys_sendmsg net/socket.c:2586 [inline] __se_sys_sendmsg net/socket.c:2584 [inline] __x64_sys_sendmsg+0x45/0x50 net/socket.c:2584 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0x90 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x6e/0xd8 read to 0xffffffff8546f2d0 of 8 bytes by task 44814 on cpu 0: too_many_unix_fds net/unix/scm.c:101 [inline] unix_attach_fds+0x54/0x1e0 net/unix/scm.c:110 unix_scm_to_skb net/unix/af_unix.c:1827 [inline] unix_dgram_sendmsg+0x46a/0x14f0 net/unix/af_unix.c:1950 unix_seqpacket_sendmsg net/unix/af_unix.c:2308 [inline] unix_seqpacket_sendmsg+0xba/0x130 net/unix/af_unix.c:2292 sock_sendmsg_nosec net/socket.c:725 [inline] sock_sendmsg+0x148/0x160 net/socket.c:748 ____sys_sendmsg+0x4e4/0x610 net/socket.c:2494 ___sys_sendmsg+0xc6/0x140 net/socket.c:2548 __sys_sendmsg+0x94/0x140 net/socket.c:2577 __do_sys_sendmsg net/socket.c:2586 [inline] __se_sys_sendmsg net/socket.c:2584 [inline] __x64_sys_sendmsg+0x45/0x50 net/socket.c:2584 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0x90 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x6e/0xd8 value changed: 0x000000000000000c -> 0x000000000000000d Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 44814 Comm: systemd-coredum Not tainted 6.4.0-11989-g6843306689af #6 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 ## Affected - `Linux >= 712f4aad406bb1ed67f3f98d04c044191f0ff593 < df97b5ea9f3ac9308c3a633524dab382cd59d9e5` - `Linux >= 712f4aad406bb1ed67f3f98d04c044191f0ff593 < 03d133dfbcec9d439729cc64706c7eb6d1663a24` - `Linux >= 712f4aad406bb1ed67f3f98d04c044191f0ff593 < adcf4e069358cdee8593663650ea447215a1c49e` - `Linux >= 712f4aad406bb1ed67f3f98d04c044191f0ff593 < b401d7e485b0a234cf8fe9a6ae99dbcd20863138` - `Linux >= 712f4aad406bb1ed67f3f98d04c044191f0ff593 < 9151ed4b006125cba7c06c79df504340ea4e9386` - `Linux >= 712f4aad406bb1ed67f3f98d04c044191f0ff593 < b9cdbb38e030fc2fe97fe27b54cbb6b4fbff250f` - `Linux >= 712f4aad406bb1ed67f3f98d04c044191f0ff593 < ac92f239a079678a035c0faad9089354a874aede` - `Linux >= 712f4aad406bb1ed67f3f98d04c044191f0ff593 < 0bc36c0650b21df36fbec8136add83936eaf0607` - `Linux a5a6cf8c405e826ff7ed1308dde72560c0ed4854` - `Linux df87da0783c4492b944badfea9d5c3c56b834697` - `Linux 3d024dcef2548028e9f9b7876a544e6e0af00175` - `Linux aa51d1c24ec3b6605f7cc7ef500c96cd71d7ef90` - `Linux a5b9e44af8d3edaf49d14a91cc519a9fba439e67` - `Linux dc6b0ec667f67d4768e72c1b7f1bbc14ea52379c` - `Linux 9b8b611fe0f86f07a4ff4a5f3bcb0ea7ceb7da3b` - `Linux 5e226f9689d90ad8ab21b4a969ae3058777f0aff` - `Linux >= 3.2.78 < 3.3` - `Linux >= 3.10.96 < 3.11` - `Linux >= 3.12.57 < 3.13` - `Linux >= 3.14.60 < 3.15` - `Linux >= 3.18.27 < 3.19` - `Linux >= 4.1.17 < 4.2` - `Linux >= 4.3.5 < 4.4` - `Linux >= 4.4.1 < 4.5` - `Linux 4.5` ## Remediation Refer to the linked advisories for vendor-supplied fixes and affected version ranges.