{"id":"CVE-2022-49081","state":"PUBLISHED","title":"highmem: fix checks in __kmap_local_sched_{in,out}","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nhighmem: fix checks in __kmap_local_sched_{in,out}\n\nWhen CONFIG_DEBUG_KMAP_LOCAL is enabled __kmap_local_sched_{in,out} check\nthat even slots in the tsk->kmap_ctrl.pteval are unmapped.  The slots are\ninitialized with 0 value, but the check is done with pte_none.  0 pte\nhowever does not necessarily mean that pte_none will return true.  e.g.\non xtensa it returns false, resulting in the following runtime warnings:\n\n WARNING: CPU: 0 PID: 101 at mm/highmem.c:627 __kmap_local_sched_out+0x51/0x108\n CPU: 0 PID: 101 Comm: touch Not tainted 5.17.0-rc7-00010-gd3a1cdde80d2-dirty #13\n Call Trace:\n   dump_stack+0xc/0x40\n   __warn+0x8f/0x174\n   warn_slowpath_fmt+0x48/0xac\n   __kmap_local_sched_out+0x51/0x108\n   __schedule+0x71a/0x9c4\n   preempt_schedule_irq+0xa0/0xe0\n   common_exception_return+0x5c/0x93\n   do_wp_page+0x30e/0x330\n   handle_mm_fault+0xa70/0xc3c\n   do_page_fault+0x1d8/0x3c4\n   common_exception+0x7f/0x7f\n\n WARNING: CPU: 0 PID: 101 at mm/highmem.c:664 __kmap_local_sched_in+0x50/0xe0\n CPU: 0 PID: 101 Comm: touch Tainted: G        W         5.17.0-rc7-00010-gd3a1cdde80d2-dirty #13\n Call Trace:\n   dump_stack+0xc/0x40\n   __warn+0x8f/0x174\n   warn_slowpath_fmt+0x48/0xac\n   __kmap_local_sched_in+0x50/0xe0\n   finish_task_switch$isra$0+0x1ce/0x2f8\n   __schedule+0x86e/0x9c4\n   preempt_schedule_irq+0xa0/0xe0\n   common_exception_return+0x5c/0x93\n   do_wp_page+0x30e/0x330\n   handle_mm_fault+0xa70/0xc3c\n   do_page_fault+0x1d8/0x3c4\n   common_exception+0x7f/0x7f\n\nFix it by replacing !pte_none(pteval) with pte_val(pteval) != 0.","publishedAt":"2025-02-26T01:54:41.639Z","updatedAt":"2026-05-11T18:52:39.819Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"5fbda3ecd14a5343644979c98d6eb65b7e7de9d8","status":"affected","lessThan":"c21d040de6225414547d9bd31cd200f290991c85","versionType":"git"},{"version":"5fbda3ecd14a5343644979c98d6eb65b7e7de9d8","status":"affected","lessThan":"85550b0f5fa5dd3c30469ea702c44444ef242c83","versionType":"git"},{"version":"5fbda3ecd14a5343644979c98d6eb65b7e7de9d8","status":"affected","lessThan":"7dd5b3b97716a611fcf67d92fd2370fcb8d50372","versionType":"git"},{"version":"5fbda3ecd14a5343644979c98d6eb65b7e7de9d8","status":"affected","lessThan":"66f133ceab7456c789f70a242991ed1b27ba1c3d","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["mm/highmem.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.11","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.11","versionType":"semver"},{"version":"5.15.34","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"5.16.20","status":"unaffected","lessThanOrEqual":"5.16.*","versionType":"semver"},{"version":"5.17.3","status":"unaffected","lessThanOrEqual":"5.17.*","versionType":"semver"},{"version":"5.18","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["mm/highmem.c"]}],"references":["https://git.kernel.org/stable/c/c21d040de6225414547d9bd31cd200f290991c85","https://git.kernel.org/stable/c/85550b0f5fa5dd3c30469ea702c44444ef242c83","https://git.kernel.org/stable/c/7dd5b3b97716a611fcf67d92fd2370fcb8d50372","https://git.kernel.org/stable/c/66f133ceab7456c789f70a242991ed1b27ba1c3d"],"weaknesses":[],"ingestedAt":"2026-10-29T20:05:26.763Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2022/49xxx/CVE-2022-49081.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2022-49081","state":"PUBLISHED","datePublished":"2025-02-26T01:54:41.639Z","dateUpdated":"2026-05-11T18:52:39.819Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2025-02-26T01:49:39.247Z"},"containers":{"cna":{"title":"highmem: fix checks in __kmap_local_sched_{in,out}","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nhighmem: fix checks in __kmap_local_sched_{in,out}\n\nWhen CONFIG_DEBUG_KMAP_LOCAL is enabled __kmap_local_sched_{in,out} check\nthat even slots in the tsk->kmap_ctrl.pteval are unmapped.  The slots are\ninitialized with 0 value, but the check is done with pte_none.  0 pte\nhowever does not necessarily mean that pte_none will return true.  e.g.\non xtensa it returns false, resulting in the following runtime warnings:\n\n WARNING: CPU: 0 PID: 101 at mm/highmem.c:627 __kmap_local_sched_out+0x51/0x108\n CPU: 0 PID: 101 Comm: touch Not tainted 5.17.0-rc7-00010-gd3a1cdde80d2-dirty #13\n Call Trace:\n   dump_stack+0xc/0x40\n   __warn+0x8f/0x174\n   warn_slowpath_fmt+0x48/0xac\n   __kmap_local_sched_out+0x51/0x108\n   __schedule+0x71a/0x9c4\n   preempt_schedule_irq+0xa0/0xe0\n   common_exception_return+0x5c/0x93\n   do_wp_page+0x30e/0x330\n   handle_mm_fault+0xa70/0xc3c\n   do_page_fault+0x1d8/0x3c4\n   common_exception+0x7f/0x7f\n\n WARNING: CPU: 0 PID: 101 at mm/highmem.c:664 __kmap_local_sched_in+0x50/0xe0\n CPU: 0 PID: 101 Comm: touch Tainted: G        W         5.17.0-rc7-00010-gd3a1cdde80d2-dirty #13\n Call Trace:\n   dump_stack+0xc/0x40\n   __warn+0x8f/0x174\n   warn_slowpath_fmt+0x48/0xac\n   __kmap_local_sched_in+0x50/0xe0\n   finish_task_switch$isra$0+0x1ce/0x2f8\n   __schedule+0x86e/0x9c4\n   preempt_schedule_irq+0xa0/0xe0\n   common_exception_return+0x5c/0x93\n   do_wp_page+0x30e/0x330\n   handle_mm_fault+0xa70/0xc3c\n   do_page_fault+0x1d8/0x3c4\n   common_exception+0x7f/0x7f\n\nFix it by replacing !pte_none(pteval) with pte_val(pteval) != 0."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"5fbda3ecd14a5343644979c98d6eb65b7e7de9d8","status":"affected","lessThan":"c21d040de6225414547d9bd31cd200f290991c85","versionType":"git"},{"version":"5fbda3ecd14a5343644979c98d6eb65b7e7de9d8","status":"affected","lessThan":"85550b0f5fa5dd3c30469ea702c44444ef242c83","versionType":"git"},{"version":"5fbda3ecd14a5343644979c98d6eb65b7e7de9d8","status":"affected","lessThan":"7dd5b3b97716a611fcf67d92fd2370fcb8d50372","versionType":"git"},{"version":"5fbda3ecd14a5343644979c98d6eb65b7e7de9d8","status":"affected","lessThan":"66f133ceab7456c789f70a242991ed1b27ba1c3d","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["mm/highmem.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.11","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.11","versionType":"semver"},{"version":"5.15.34","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"5.16.20","status":"unaffected","lessThanOrEqual":"5.16.*","versionType":"semver"},{"version":"5.17.3","status":"unaffected","lessThanOrEqual":"5.17.*","versionType":"semver"},{"version":"5.18","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["mm/highmem.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/c21d040de6225414547d9bd31cd200f290991c85"},{"url":"https://git.kernel.org/stable/c/85550b0f5fa5dd3c30469ea702c44444ef242c83"},{"url":"https://git.kernel.org/stable/c/7dd5b3b97716a611fcf67d92fd2370fcb8d50372"},{"url":"https://git.kernel.org/stable/c/66f133ceab7456c789f70a242991ed1b27ba1c3d"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-05-11T18:52:39.819Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.11","versionEndExcluding":"5.15.34"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.11","versionEndExcluding":"5.16.20"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.11","versionEndExcluding":"5.17.3"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.11","versionEndExcluding":"5.18"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}