{ "schemaVersion": 1, "attribution": [ { "source": "CISA Known Exploited Vulnerabilities", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog", "licence": "US government work" }, { "source": "GitHub Advisory Database", "url": "https://github.com/advisories", "licence": "CC BY 4.0" }, { "source": "Have I Been Pwned", "url": "https://haveibeenpwned.com/", "licence": "CC BY 4.0" }, { "source": "CVE Program (CVE records)", "url": "https://www.cve.org/Legal/TermsOfUse", "licence": "CVE Terms of Use", "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.", "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy." }, { "source": "FIRST EPSS", "url": "https://www.first.org/epss/", "licence": "free to use; FIRST requests attribution" } ], "record": { "id": "CVE-2023-53668", "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2023-53668", "idYear": 2023, "status": "PUBLISHED", "publishedAt": "2025-10-07T15:21:26.164Z", "updatedAt": "2026-05-11T19:49:36.478Z", "importedAt": "2026-10-24T01:57:03.413Z", "snapshot": { "id": "cve_2026-10-24_midnight_baseline", "at": "2026-10-24T00:00:00.000Z", "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z" }, "facts": { "title": "ring-buffer: Fix deadloop issue on reading trace_pipe", "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nring-buffer: Fix deadloop issue on reading trace_pipe\n\nSoft lockup occurs when reading file 'trace_pipe':\n\n watchdog: BUG: soft lockup - CPU#6 stuck for 22s! [cat:4488]\n [...]\n RIP: 0010:ring_buffer_empty_cpu+0xed/0x170\n RSP: 0018:ffff88810dd6fc48 EFLAGS: 00000246\n RAX: 0000000000000000 RBX: 0000000000000246 RCX: ffffffff93d1aaeb\n RDX: ffff88810a280040 RSI: 0000000000000008 RDI: ffff88811164b218\n RBP: ffff88811164b218 R08: 0000000000000000 R09: ffff88815156600f\n R10: ffffed102a2acc01 R11: 0000000000000001 R12: 0000000051651901\n R13: 0000000000000000 R14: ffff888115e49500 R15: 0000000000000000\n [...]\n CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n CR2: 00007f8d853c2000 CR3: 000000010dcd8000 CR4: 00000000000006e0\n DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000\n DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400\n Call Trace:\n __find_next_entry+0x1a8/0x4b0\n ? peek_next_entry+0x250/0x250\n ? down_write+0xa5/0x120\n ? down_write_killable+0x130/0x130\n trace_find_next_entry_inc+0x3b/0x1d0\n tracing_read_pipe+0x423/0xae0\n ? tracing_splice_read_pipe+0xcb0/0xcb0\n vfs_read+0x16b/0x490\n ksys_read+0x105/0x210\n ? __ia32_sys_pwrite64+0x200/0x200\n ? switch_fpu_return+0x108/0x220\n do_syscall_64+0x33/0x40\n entry_SYSCALL_64_after_hwframe+0x61/0xc6\n\nThrough the vmcore, I found it's because in tracing_read_pipe(),\nring_buffer_empty_cpu() found some buffer is not empty but then it\ncannot read anything due to \"rb_num_of_entries() == 0\" always true,\nThen it infinitely loop the procedure due to user buffer not been\nfilled, see following code path:\n\n tracing_read_pipe() {\n ... ...\n waitagain:\n tracing_wait_pipe() // 1. find non-empty buffer here\n trace_find_next_entry_inc() // 2. loop here try to find an entry\n __find_next_entry()\n ring_buffer_empty_cpu(); // 3. find non-empty buffer\n peek_next_entry() // 4. but peek always return NULL\n ring_buffer_peek()\n rb_buffer_peek()\n rb_get_reader_page()\n // 5. because rb_num_of_entries() == 0 always true here\n // then return NULL\n // 6. user buffer not been filled so goto 'waitgain'\n // and eventually leads to an deadloop in kernel!!!\n }\n\nBy some analyzing, I found that when resetting ringbuffer, the 'entries'\nof its pages are not all cleared (see rb_reset_cpu()). Then when reducing\nthe ringbuffer, and if some reduced pages exist dirty 'entries' data, they\nwill be added into 'cpu_buffer->overrun' (see rb_remove_pages()), which\ncause wrong 'overrun' count and eventually cause the deadloop issue.\n\nTo fix it, we need to clear every pages in rb_reset_cpu().", "affected": [ { "vendor": "Linux", "product": "Linux", "defaultStatus": "unaffected", "versions": [ { "version": "a5fb833172eca69136e9ee1ada778e404086ab8a", "status": "affected", "versionType": "git", "lessThan": "0a29dae5786d263016a9aceb1e56bf3fd4cc6fa0" }, { "version": "a5fb833172eca69136e9ee1ada778e404086ab8a", "status": "affected", "versionType": "git", "lessThan": "a55e8a3596048c2f7b574049aeb1885b5abba1cc" }, { "version": "a5fb833172eca69136e9ee1ada778e404086ab8a", "status": "affected", "versionType": "git", "lessThan": "e84829522fc72bb43556b31575731de0440ac0dd" }, { "version": "a5fb833172eca69136e9ee1ada778e404086ab8a", "status": "affected", "versionType": "git", "lessThan": "5e68f1f3a20fe9b6bde018e353269fbfa289609c" }, { "version": "a5fb833172eca69136e9ee1ada778e404086ab8a", "status": "affected", "versionType": "git", "lessThan": "bb14a93bccc92766b1d9302c6bcbea17d4bce306" }, { "version": "a5fb833172eca69136e9ee1ada778e404086ab8a", "status": "affected", "versionType": "git", "lessThan": "8b0b63fdac6b70a45614e7d4b30e5bbb93deb007" }, { "version": "a5fb833172eca69136e9ee1ada778e404086ab8a", "status": "affected", "versionType": "git", "lessThan": "27bdd93e44cc28dd9b94893fae146b83d4f5b31e" }, { "version": "a5fb833172eca69136e9ee1ada778e404086ab8a", "status": "affected", "versionType": "git", "lessThan": "7e42907f3a7b4ce3a2d1757f6d78336984daf8f5" } ] }, { "vendor": "Linux", "product": "Linux", "defaultStatus": "affected", "versions": [ { "version": "3.6", "status": "affected" }, { "version": "0", "status": "unaffected", "versionType": "semver", "lessThan": "3.6" }, { "version": "4.14.322", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "4.14.*" }, { "version": "4.19.291", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "4.19.*" }, { "version": "5.4.251", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "5.4.*" }, { "version": "5.10.188", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "5.10.*" }, { "version": "5.15.121", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "5.15.*" }, { "version": "6.1.40", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.1.*" }, { "version": "6.4.5", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.4.*" }, { "version": "6.5", "status": "unaffected", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*" } ] } ] } } }