{"id":"CVE-2021-47256","state":"PUBLISHED","title":"mm/memory-failure: make sure wait for page writeback in memory_failure","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nmm/memory-failure: make sure wait for page writeback in memory_failure\n\nOur syzkaller trigger the \"BUG_ON(!list_empty(&inode->i_wb_list))\" in\nclear_inode:\n\n  kernel BUG at fs/inode.c:519!\n  Internal error: Oops - BUG: 0 [#1] SMP\n  Modules linked in:\n  Process syz-executor.0 (pid: 249, stack limit = 0x00000000a12409d7)\n  CPU: 1 PID: 249 Comm: syz-executor.0 Not tainted 4.19.95\n  Hardware name: linux,dummy-virt (DT)\n  pstate: 80000005 (Nzcv daif -PAN -UAO)\n  pc : clear_inode+0x280/0x2a8\n  lr : clear_inode+0x280/0x2a8\n  Call trace:\n    clear_inode+0x280/0x2a8\n    ext4_clear_inode+0x38/0xe8\n    ext4_free_inode+0x130/0xc68\n    ext4_evict_inode+0xb20/0xcb8\n    evict+0x1a8/0x3c0\n    iput+0x344/0x460\n    do_unlinkat+0x260/0x410\n    __arm64_sys_unlinkat+0x6c/0xc0\n    el0_svc_common+0xdc/0x3b0\n    el0_svc_handler+0xf8/0x160\n    el0_svc+0x10/0x218\n  Kernel panic - not syncing: Fatal exception\n\nA crash dump of this problem show that someone called __munlock_pagevec\nto clear page LRU without lock_page: do_mmap -> mmap_region -> do_munmap\n-> munlock_vma_pages_range -> __munlock_pagevec.\n\nAs a result memory_failure will call identify_page_state without\nwait_on_page_writeback.  And after truncate_error_page clear the mapping\nof this page.  end_page_writeback won't call sb_clear_inode_writeback to\nclear inode->i_wb_list.  That will trigger BUG_ON in clear_inode!\n\nFix it by checking PageWriteback too to help determine should we skip\nwait_on_page_writeback.","publishedAt":"2024-05-21T14:19:50.777Z","updatedAt":"2026-05-11T13:50:58.894Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"0bc1f8b0682caa39f45ce1e0228ebf43acb46111","status":"affected","lessThan":"d05267fd27a5c4f54e06daefa3035995d765ca0c","versionType":"git"},{"version":"0bc1f8b0682caa39f45ce1e0228ebf43acb46111","status":"affected","lessThan":"6d210d547adc2218ef8b5bcf23518c5f2f1fd872","versionType":"git"},{"version":"0bc1f8b0682caa39f45ce1e0228ebf43acb46111","status":"affected","lessThan":"566345aaabac853aa866f53a219c4b02a6beb527","versionType":"git"},{"version":"0bc1f8b0682caa39f45ce1e0228ebf43acb46111","status":"affected","lessThan":"9e379da727a7a031be9b877cde7b9c34a0fb8306","versionType":"git"},{"version":"0bc1f8b0682caa39f45ce1e0228ebf43acb46111","status":"affected","lessThan":"28788dc5c70597395b6b451dae4549bbaa8e2c56","versionType":"git"},{"version":"0bc1f8b0682caa39f45ce1e0228ebf43acb46111","status":"affected","lessThan":"e8675d291ac007e1c636870db880f837a9ea112a","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["mm/memory-failure.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.16","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.16","versionType":"semver"},{"version":"4.14.238","status":"unaffected","lessThanOrEqual":"4.14.*","versionType":"semver"},{"version":"4.19.196","status":"unaffected","lessThanOrEqual":"4.19.*","versionType":"semver"},{"version":"5.4.128","status":"unaffected","lessThanOrEqual":"5.4.*","versionType":"semver"},{"version":"5.10.46","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.12.13","status":"unaffected","lessThanOrEqual":"5.12.*","versionType":"semver"},{"version":"5.13","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["mm/memory-failure.c"]}],"references":["https://git.kernel.org/stable/c/d05267fd27a5c4f54e06daefa3035995d765ca0c","https://git.kernel.org/stable/c/6d210d547adc2218ef8b5bcf23518c5f2f1fd872","https://git.kernel.org/stable/c/566345aaabac853aa866f53a219c4b02a6beb527","https://git.kernel.org/stable/c/9e379da727a7a031be9b877cde7b9c34a0fb8306","https://git.kernel.org/stable/c/28788dc5c70597395b6b451dae4549bbaa8e2c56","https://git.kernel.org/stable/c/e8675d291ac007e1c636870db880f837a9ea112a"],"weaknesses":[],"ingestedAt":"2026-10-29T19:49:19.404Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2021/47xxx/CVE-2021-47256.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2021-47256","state":"PUBLISHED","datePublished":"2024-05-21T14:19:50.777Z","dateUpdated":"2026-05-11T13:50:58.894Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2024-04-10T18:59:19.540Z"},"containers":{"cna":{"title":"mm/memory-failure: make sure wait for page writeback in memory_failure","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nmm/memory-failure: make sure wait for page writeback in memory_failure\n\nOur syzkaller trigger the \"BUG_ON(!list_empty(&inode->i_wb_list))\" in\nclear_inode:\n\n  kernel BUG at fs/inode.c:519!\n  Internal error: Oops - BUG: 0 [#1] SMP\n  Modules linked in:\n  Process syz-executor.0 (pid: 249, stack limit = 0x00000000a12409d7)\n  CPU: 1 PID: 249 Comm: syz-executor.0 Not tainted 4.19.95\n  Hardware name: linux,dummy-virt (DT)\n  pstate: 80000005 (Nzcv daif -PAN -UAO)\n  pc : clear_inode+0x280/0x2a8\n  lr : clear_inode+0x280/0x2a8\n  Call trace:\n    clear_inode+0x280/0x2a8\n    ext4_clear_inode+0x38/0xe8\n    ext4_free_inode+0x130/0xc68\n    ext4_evict_inode+0xb20/0xcb8\n    evict+0x1a8/0x3c0\n    iput+0x344/0x460\n    do_unlinkat+0x260/0x410\n    __arm64_sys_unlinkat+0x6c/0xc0\n    el0_svc_common+0xdc/0x3b0\n    el0_svc_handler+0xf8/0x160\n    el0_svc+0x10/0x218\n  Kernel panic - not syncing: Fatal exception\n\nA crash dump of this problem show that someone called __munlock_pagevec\nto clear page LRU without lock_page: do_mmap -> mmap_region -> do_munmap\n-> munlock_vma_pages_range -> __munlock_pagevec.\n\nAs a result memory_failure will call identify_page_state without\nwait_on_page_writeback.  And after truncate_error_page clear the mapping\nof this page.  end_page_writeback won't call sb_clear_inode_writeback to\nclear inode->i_wb_list.  That will trigger BUG_ON in clear_inode!\n\nFix it by checking PageWriteback too to help determine should we skip\nwait_on_page_writeback."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"0bc1f8b0682caa39f45ce1e0228ebf43acb46111","status":"affected","lessThan":"d05267fd27a5c4f54e06daefa3035995d765ca0c","versionType":"git"},{"version":"0bc1f8b0682caa39f45ce1e0228ebf43acb46111","status":"affected","lessThan":"6d210d547adc2218ef8b5bcf23518c5f2f1fd872","versionType":"git"},{"version":"0bc1f8b0682caa39f45ce1e0228ebf43acb46111","status":"affected","lessThan":"566345aaabac853aa866f53a219c4b02a6beb527","versionType":"git"},{"version":"0bc1f8b0682caa39f45ce1e0228ebf43acb46111","status":"affected","lessThan":"9e379da727a7a031be9b877cde7b9c34a0fb8306","versionType":"git"},{"version":"0bc1f8b0682caa39f45ce1e0228ebf43acb46111","status":"affected","lessThan":"28788dc5c70597395b6b451dae4549bbaa8e2c56","versionType":"git"},{"version":"0bc1f8b0682caa39f45ce1e0228ebf43acb46111","status":"affected","lessThan":"e8675d291ac007e1c636870db880f837a9ea112a","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["mm/memory-failure.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.16","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.16","versionType":"semver"},{"version":"4.14.238","status":"unaffected","lessThanOrEqual":"4.14.*","versionType":"semver"},{"version":"4.19.196","status":"unaffected","lessThanOrEqual":"4.19.*","versionType":"semver"},{"version":"5.4.128","status":"unaffected","lessThanOrEqual":"5.4.*","versionType":"semver"},{"version":"5.10.46","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.12.13","status":"unaffected","lessThanOrEqual":"5.12.*","versionType":"semver"},{"version":"5.13","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["mm/memory-failure.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/d05267fd27a5c4f54e06daefa3035995d765ca0c"},{"url":"https://git.kernel.org/stable/c/6d210d547adc2218ef8b5bcf23518c5f2f1fd872"},{"url":"https://git.kernel.org/stable/c/566345aaabac853aa866f53a219c4b02a6beb527"},{"url":"https://git.kernel.org/stable/c/9e379da727a7a031be9b877cde7b9c34a0fb8306"},{"url":"https://git.kernel.org/stable/c/28788dc5c70597395b6b451dae4549bbaa8e2c56"},{"url":"https://git.kernel.org/stable/c/e8675d291ac007e1c636870db880f837a9ea112a"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-05-11T13:50:58.894Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.16","versionEndExcluding":"4.14.238"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.16","versionEndExcluding":"4.19.196"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.16","versionEndExcluding":"5.4.128"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.16","versionEndExcluding":"5.10.46"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.16","versionEndExcluding":"5.12.13"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.16","versionEndExcluding":"5.13"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CVE Program Container","references":[{"url":"https://git.kernel.org/stable/c/d05267fd27a5c4f54e06daefa3035995d765ca0c","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/6d210d547adc2218ef8b5bcf23518c5f2f1fd872","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/566345aaabac853aa866f53a219c4b02a6beb527","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/9e379da727a7a031be9b877cde7b9c34a0fb8306","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/28788dc5c70597395b6b451dae4549bbaa8e2c56","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/e8675d291ac007e1c636870db880f837a9ea112a","tags":["x_transferred"]}],"providerMetadata":{"shortName":"CVE","orgId":"af854a3a-2127-422b-91ae-364da2661108","dateUpdated":"2024-08-04T05:32:07.937Z"}},{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2021-47256","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2024-09-10T15:39:51.420544Z"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2024-09-11T17:33:11.735Z"}}]}}}