{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2023-53668", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-10-07T15:16:59.663Z", "datePublished": "2025-10-07T15:21:26.164Z", "dateUpdated": "2026-05-11T19:49:36.478Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-05-11T19:49:36.478Z" }, "descriptions": [ { "lang": "en", "value": "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": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "kernel/trace/ring_buffer.c" ], "versions": [ { "version": "a5fb833172eca69136e9ee1ada778e404086ab8a", "lessThan": "0a29dae5786d263016a9aceb1e56bf3fd4cc6fa0", "status": "affected", "versionType": "git" }, { "version": "a5fb833172eca69136e9ee1ada778e404086ab8a", "lessThan": "a55e8a3596048c2f7b574049aeb1885b5abba1cc", "status": "affected", "versionType": "git" }, { "version": "a5fb833172eca69136e9ee1ada778e404086ab8a", "lessThan": "e84829522fc72bb43556b31575731de0440ac0dd", "status": "affected", "versionType": "git" }, { "version": "a5fb833172eca69136e9ee1ada778e404086ab8a", "lessThan": "5e68f1f3a20fe9b6bde018e353269fbfa289609c", "status": "affected", "versionType": "git" }, { "version": "a5fb833172eca69136e9ee1ada778e404086ab8a", "lessThan": "bb14a93bccc92766b1d9302c6bcbea17d4bce306", "status": "affected", "versionType": "git" }, { "version": "a5fb833172eca69136e9ee1ada778e404086ab8a", "lessThan": "8b0b63fdac6b70a45614e7d4b30e5bbb93deb007", "status": "affected", "versionType": "git" }, { "version": "a5fb833172eca69136e9ee1ada778e404086ab8a", "lessThan": "27bdd93e44cc28dd9b94893fae146b83d4f5b31e", "status": "affected", "versionType": "git" }, { "version": "a5fb833172eca69136e9ee1ada778e404086ab8a", "lessThan": "7e42907f3a7b4ce3a2d1757f6d78336984daf8f5", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "kernel/trace/ring_buffer.c" ], "versions": [ { "version": "3.6", "status": "affected" }, { "version": "0", "lessThan": "3.6", "status": "unaffected", "versionType": "semver" }, { "version": "4.14.322", "lessThanOrEqual": "4.14.*", "status": "unaffected", "versionType": "semver" }, { "version": "4.19.291", "lessThanOrEqual": "4.19.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.4.251", "lessThanOrEqual": "5.4.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.188", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.121", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.40", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.4.5", "lessThanOrEqual": "6.4.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.5", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.6", "versionEndExcluding": "4.14.322" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.6", "versionEndExcluding": "4.19.291" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.6", "versionEndExcluding": "5.4.251" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.6", "versionEndExcluding": "5.10.188" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.6", "versionEndExcluding": "5.15.121" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.6", "versionEndExcluding": "6.1.40" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.6", "versionEndExcluding": "6.4.5" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.6", "versionEndExcluding": "6.5" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/0a29dae5786d263016a9aceb1e56bf3fd4cc6fa0" }, { "url": "https://git.kernel.org/stable/c/a55e8a3596048c2f7b574049aeb1885b5abba1cc" }, { "url": "https://git.kernel.org/stable/c/e84829522fc72bb43556b31575731de0440ac0dd" }, { "url": "https://git.kernel.org/stable/c/5e68f1f3a20fe9b6bde018e353269fbfa289609c" }, { "url": "https://git.kernel.org/stable/c/bb14a93bccc92766b1d9302c6bcbea17d4bce306" }, { "url": "https://git.kernel.org/stable/c/8b0b63fdac6b70a45614e7d4b30e5bbb93deb007" }, { "url": "https://git.kernel.org/stable/c/27bdd93e44cc28dd9b94893fae146b83d4f5b31e" }, { "url": "https://git.kernel.org/stable/c/7e42907f3a7b4ce3a2d1757f6d78336984daf8f5" } ], "title": "ring-buffer: Fix deadloop issue on reading trace_pipe", "x_generator": { "engine": "bippy-1.2.0" } } } }