| { |
| "containers": { |
| "cna": { |
| "providerMetadata": { |
| "orgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038" |
| }, |
| "descriptions": [ |
| { |
| "lang": "en", |
| "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/hugetlb: fix PTE marker handling in hugetlb_change_protection()\n\nPatch series \"mm/hugetlb: uffd-wp fixes for hugetlb_change_protection()\".\n\nPlaying with virtio-mem and background snapshots (using uffd-wp) on\nhugetlb in QEMU, I managed to trigger a VM_BUG_ON(). Looking into the\ndetails, hugetlb_change_protection() seems to not handle uffd-wp correctly\nin all cases.\n\nPatch #1 fixes my test case. I don't have reproducers for patch #2, as it\nrequires running into migration entries.\n\nI did not yet check in detail yet if !hugetlb code requires similar care.\n\n\nThis patch (of 2):\n\nThere are two problematic cases when stumbling over a PTE marker in\nhugetlb_change_protection():\n\n(1) We protect an uffd-wp PTE marker a second time using uffd-wp: we will\n end up in the \"!huge_pte_none(pte)\" case and mess up the PTE marker.\n\n(2) We unprotect a uffd-wp PTE marker: we will similarly end up in the\n \"!huge_pte_none(pte)\" case even though we cleared the PTE, because\n the \"pte\" variable is stale. We'll mess up the PTE marker.\n\nFor example, if we later stumble over such a \"wrongly modified\" PTE marker,\nwe'll treat it like a present PTE that maps some garbage page.\n\nThis can, for example, be triggered by mapping a memfd backed by huge\npages, registering uffd-wp, uffd-wp'ing an unmapped page and (a)\nuffd-wp'ing it a second time; or (b) uffd-unprotecting it; or (c)\nunregistering uffd-wp. Then, ff we trigger fallocate(FALLOC_FL_PUNCH_HOLE)\non that file range, we will run into a VM_BUG_ON:\n\n[ 195.039560] page:00000000ba1f2987 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x0\n[ 195.039565] flags: 0x7ffffc0001000(reserved|node=0|zone=0|lastcpupid=0x1fffff)\n[ 195.039568] raw: 0007ffffc0001000 ffffe742c0000008 ffffe742c0000008 0000000000000000\n[ 195.039569] raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000\n[ 195.039569] page dumped because: VM_BUG_ON_PAGE(compound && !PageHead(page))\n[ 195.039573] ------------[ cut here ]------------\n[ 195.039574] kernel BUG at mm/rmap.c:1346!\n[ 195.039579] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI\n[ 195.039581] CPU: 7 PID: 4777 Comm: qemu-system-x86 Not tainted 6.0.12-200.fc36.x86_64 #1\n[ 195.039583] Hardware name: LENOVO 20WNS1F81N/20WNS1F81N, BIOS N35ET50W (1.50 ) 09/15/2022\n[ 195.039584] RIP: 0010:page_remove_rmap+0x45b/0x550\n[ 195.039588] Code: [...]\n[ 195.039589] RSP: 0018:ffffbc03c3633ba8 EFLAGS: 00010292\n[ 195.039591] RAX: 0000000000000040 RBX: ffffe742c0000000 RCX: 0000000000000000\n[ 195.039592] RDX: 0000000000000002 RSI: ffffffff8e7aac1a RDI: 00000000ffffffff\n[ 195.039592] RBP: 0000000000000001 R08: 0000000000000000 R09: ffffbc03c3633a08\n[ 195.039593] R10: 0000000000000003 R11: ffffffff8f146328 R12: ffff9b04c42754b0\n[ 195.039594] R13: ffffffff8fcc6328 R14: ffffbc03c3633c80 R15: ffff9b0484ab9100\n[ 195.039595] FS: 00007fc7aaf68640(0000) GS:ffff9b0bbf7c0000(0000) knlGS:0000000000000000\n[ 195.039596] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n[ 195.039597] CR2: 000055d402c49110 CR3: 0000000159392003 CR4: 0000000000772ee0\n[ 195.039598] PKRU: 55555554\n[ 195.039599] Call Trace:\n[ 195.039600] <TASK>\n[ 195.039602] __unmap_hugepage_range+0x33b/0x7d0\n[ 195.039605] unmap_hugepage_range+0x55/0x70\n[ 195.039608] hugetlb_vmdelete_list+0x77/0xa0\n[ 195.039611] hugetlbfs_fallocate+0x410/0x550\n[ 195.039612] ? _raw_spin_unlock_irqrestore+0x23/0x40\n[ 195.039616] vfs_fallocate+0x12e/0x360\n[ 195.039618] __x64_sys_fallocate+0x40/0x70\n[ 195.039620] do_syscall_64+0x58/0x80\n[ 195.039623] ? syscall_exit_to_user_mode+0x17/0x40\n[ 195.039624] ? do_syscall_64+0x67/0x80\n[ 195.039626] entry_SYSCALL_64_after_hwframe+0x63/0xcd\n[ 195.039628] RIP: 0033:0x7fc7b590651f\n[ 195.039653] Code: [...]\n[ 195.039654] RSP: 002b:00007fc7aaf66e70 EFLAGS: 00000293 ORIG_RAX: 000000000000011d\n[ 195.039655] RAX: ffffffffffffffda RBX: 0000558ef4b7f370 RCX: 00007fc7b590651f\n---truncated---" |
| } |
| ], |
| "affected": [ |
| { |
| "product": "Linux", |
| "vendor": "Linux", |
| "defaultStatus": "unaffected", |
| "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", |
| "programFiles": [ |
| "mm/hugetlb.c" |
| ], |
| "versions": [ |
| { |
| "version": "60dfaad65aa97fb6755b9798a6b3c9e79bcd5930", |
| "lessThan": "6062c992e912df1eedad52cf64efb3d48e8d35c5", |
| "status": "affected", |
| "versionType": "git" |
| }, |
| { |
| "version": "60dfaad65aa97fb6755b9798a6b3c9e79bcd5930", |
| "lessThan": "0e678153f5be7e6c8d28835f5a678618da4b7a9c", |
| "status": "affected", |
| "versionType": "git" |
| } |
| ] |
| }, |
| { |
| "product": "Linux", |
| "vendor": "Linux", |
| "defaultStatus": "affected", |
| "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", |
| "programFiles": [ |
| "mm/hugetlb.c" |
| ], |
| "versions": [ |
| { |
| "version": "5.19", |
| "status": "affected" |
| }, |
| { |
| "version": "0", |
| "lessThan": "5.19", |
| "status": "unaffected", |
| "versionType": "semver" |
| }, |
| { |
| "version": "6.1.8", |
| "lessThanOrEqual": "6.1.*", |
| "status": "unaffected", |
| "versionType": "semver" |
| }, |
| { |
| "version": "6.2", |
| "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": "5.19", |
| "versionEndExcluding": "6.1.8" |
| }, |
| { |
| "vulnerable": true, |
| "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", |
| "versionStartIncluding": "5.19", |
| "versionEndExcluding": "6.2" |
| } |
| ] |
| } |
| ] |
| } |
| ], |
| "references": [ |
| { |
| "url": "https://git.kernel.org/stable/c/6062c992e912df1eedad52cf64efb3d48e8d35c5" |
| }, |
| { |
| "url": "https://git.kernel.org/stable/c/0e678153f5be7e6c8d28835f5a678618da4b7a9c" |
| } |
| ], |
| "title": "mm/hugetlb: fix PTE marker handling in hugetlb_change_protection()", |
| "x_generator": { |
| "engine": "bippy-1.2.0" |
| } |
| } |
| }, |
| "cveMetadata": { |
| "assignerOrgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038", |
| "cveID": "CVE-2022-49760", |
| "requesterUserId": "gregkh@kernel.org", |
| "serial": "1", |
| "state": "PUBLISHED" |
| }, |
| "dataType": "CVE_RECORD", |
| "dataVersion": "5.0" |
| } |
