GHSA-P52G-5QGX-4CRW
Vulnerability from github – Published: 2024-05-21 15:31 – Updated: 2025-04-30 15:30In the Linux kernel, the following vulnerability has been resolved:
mm/memory-failure: make sure wait for page writeback in memory_failure
Our syzkaller trigger the "BUG_ON(!list_empty(&inode->i_wb_list))" in clear_inode:
kernel BUG at fs/inode.c:519! Internal error: Oops - BUG: 0 [#1] SMP Modules linked in: Process syz-executor.0 (pid: 249, stack limit = 0x00000000a12409d7) CPU: 1 PID: 249 Comm: syz-executor.0 Not tainted 4.19.95 Hardware name: linux,dummy-virt (DT) pstate: 80000005 (Nzcv daif -PAN -UAO) pc : clear_inode+0x280/0x2a8 lr : clear_inode+0x280/0x2a8 Call trace: clear_inode+0x280/0x2a8 ext4_clear_inode+0x38/0xe8 ext4_free_inode+0x130/0xc68 ext4_evict_inode+0xb20/0xcb8 evict+0x1a8/0x3c0 iput+0x344/0x460 do_unlinkat+0x260/0x410 __arm64_sys_unlinkat+0x6c/0xc0 el0_svc_common+0xdc/0x3b0 el0_svc_handler+0xf8/0x160 el0_svc+0x10/0x218 Kernel panic - not syncing: Fatal exception
A crash dump of this problem show that someone called __munlock_pagevec to clear page LRU without lock_page: do_mmap -> mmap_region -> do_munmap -> munlock_vma_pages_range -> __munlock_pagevec.
As a result memory_failure will call identify_page_state without wait_on_page_writeback. And after truncate_error_page clear the mapping of this page. end_page_writeback won't call sb_clear_inode_writeback to clear inode->i_wb_list. That will trigger BUG_ON in clear_inode!
Fix it by checking PageWriteback too to help determine should we skip wait_on_page_writeback.
{
"affected": [],
"aliases": [
"CVE-2021-47256"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-05-21T15:15:14Z",
"severity": "MODERATE"
},
"details": "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(\u0026inode-\u003ei_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 -\u003e mmap_region -\u003e do_munmap\n-\u003e munlock_vma_pages_range -\u003e __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\u0027t call sb_clear_inode_writeback to\nclear inode-\u003ei_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.",
"id": "GHSA-p52g-5qgx-4crw",
"modified": "2025-04-30T15:30:43Z",
"published": "2024-05-21T15:31:40Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2021-47256"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/28788dc5c70597395b6b451dae4549bbaa8e2c56"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/566345aaabac853aa866f53a219c4b02a6beb527"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/6d210d547adc2218ef8b5bcf23518c5f2f1fd872"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/9e379da727a7a031be9b877cde7b9c34a0fb8306"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/d05267fd27a5c4f54e06daefa3035995d765ca0c"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/e8675d291ac007e1c636870db880f837a9ea112a"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
Sightings
| Author | Source | Type | Date |
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