{"id":"CVE-2026-53243","state":"PUBLISHED","title":"rseq: Fix using an uninitialized stack variable in rseq_exit_user_update()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nrseq: Fix using an uninitialized stack variable in rseq_exit_user_update()\n\nThere is an bug in which an uninitialized stack variable is used in\nrseq_exit_user_update() as reported by syzbot:\n\nBUG: KMSAN: kernel-infoleak in rseq_set_ids_get_csaddr include/linux/rseq_entry.h:502 [inline]\n\nThe local variable:\n\n\tstruct rseq_ids ids = {\n\t\t.cpu_id\t = task_cpu(t),\n\t\t.mm_cid\t = task_mm_cid(t),\n\t\t.node_id = cpu_to_node(ids.cpu_id),\n\t};\n\nAccording to the C standard, the evaluation order of expressions in an\ninitializer list is indeterminately sequenced. The compiler (Clang, in\nthis KMSAN build) evaluates `cpu_to_node(ids.cpu_id)` *before*\n`ids.cpu_id` is initialized with `task_cpu(t)`.\n\nThis is fixed by moving the assignment of ids.node_id outside the\nstructure initialization.","publishedAt":"2026-06-25T08:39:37.794Z","updatedAt":"2026-06-25T08:39:37.794Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"d242126fd21ab8f1631fdbc8589e43a9d4229f3b","status":"affected","lessThan":"e12d20a63b61aaf9de4772effccf42cc9a003e58","versionType":"git"},{"version":"82f572449cfe75f12ea985986da60e11f308f77d","status":"affected","lessThan":"6d99479799c69c3cb588fcda19c81d8f61d64ecd","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["include/linux/rseq_entry.h"]},{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"7.0.10","status":"affected","lessThan":"7.0.13","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["include/linux/rseq_entry.h"]}],"references":["https://git.kernel.org/stable/c/e12d20a63b61aaf9de4772effccf42cc9a003e58","https://git.kernel.org/stable/c/6d99479799c69c3cb588fcda19c81d8f61d64ecd"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:16.098Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/53xxx/CVE-2026-53243.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-53243","state":"PUBLISHED","datePublished":"2026-06-25T08:39:37.794Z","dateUpdated":"2026-06-25T08:39:37.794Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-06-09T07:44:35.393Z"},"containers":{"cna":{"title":"rseq: Fix using an uninitialized stack variable in rseq_exit_user_update()","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nrseq: Fix using an uninitialized stack variable in rseq_exit_user_update()\n\nThere is an bug in which an uninitialized stack variable is used in\nrseq_exit_user_update() as reported by syzbot:\n\nBUG: KMSAN: kernel-infoleak in rseq_set_ids_get_csaddr include/linux/rseq_entry.h:502 [inline]\n\nThe local variable:\n\n\tstruct rseq_ids ids = {\n\t\t.cpu_id\t = task_cpu(t),\n\t\t.mm_cid\t = task_mm_cid(t),\n\t\t.node_id = cpu_to_node(ids.cpu_id),\n\t};\n\nAccording to the C standard, the evaluation order of expressions in an\ninitializer list is indeterminately sequenced. The compiler (Clang, in\nthis KMSAN build) evaluates `cpu_to_node(ids.cpu_id)` *before*\n`ids.cpu_id` is initialized with `task_cpu(t)`.\n\nThis is fixed by moving the assignment of ids.node_id outside the\nstructure initialization."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"d242126fd21ab8f1631fdbc8589e43a9d4229f3b","status":"affected","lessThan":"e12d20a63b61aaf9de4772effccf42cc9a003e58","versionType":"git"},{"version":"82f572449cfe75f12ea985986da60e11f308f77d","status":"affected","lessThan":"6d99479799c69c3cb588fcda19c81d8f61d64ecd","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["include/linux/rseq_entry.h"]},{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"7.0.10","status":"affected","lessThan":"7.0.13","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["include/linux/rseq_entry.h"]}],"references":[{"url":"https://git.kernel.org/stable/c/e12d20a63b61aaf9de4772effccf42cc9a003e58"},{"url":"https://git.kernel.org/stable/c/6d99479799c69c3cb588fcda19c81d8f61d64ecd"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-06-25T08:39:37.794Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"7.0.10","versionEndExcluding":"7.0.13"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}