{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-64061", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T07:54:57.030Z", "datePublished": "2026-07-19T15:39:40.913Z", "dateUpdated": "2026-08-05T12:38:49.000Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:38:49.000Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfs: Fix early put of sink folio in netfs_read_gaps()\n\nFix netfs_read_gaps() to release the sink page it uses after waiting for\nthe request to complete. The way the sink page is used is that an\nITER_BVEC-class iterator is created that has the gaps from the target folio\nat either end, but has the sink page tiled over the middle so that a single\nread op can fill in both gaps.\n\nThe bug was found by KASAN detecting a UAF on the generic/075 xfstest in\nthe cifsd kernel thread that handles reception of data from the TCP socket:\n\n BUG: KASAN: use-after-free in _copy_to_iter+0x48a/0xa20\n Write of size 885 at addr ffff888107f92000 by task cifsd/1285\n CPU: 2 UID: 0 PID: 1285 Comm: cifsd Not tainted 7.0.0 #6 PREEMPT(lazy)\n Call Trace:\n dump_stack_lvl+0x5d/0x80\n print_report+0x17f/0x4f1\n kasan_report+0x100/0x1e0\n kasan_check_range+0x10f/0x1e0\n __asan_memcpy+0x3c/0x60\n _copy_to_iter+0x48a/0xa20\n __skb_datagram_iter+0x2c9/0x430\n skb_copy_datagram_iter+0x6e/0x160\n tcp_recvmsg_locked+0xce0/0x1130\n tcp_recvmsg+0xeb/0x300\n inet_recvmsg+0xcf/0x3a0\n sock_recvmsg+0xea/0x100\n cifs_readv_from_socket+0x3a6/0x4d0 [cifs]\n cifs_read_iter_from_socket+0xdd/0x130 [cifs]\n cifs_readv_receive+0xaad/0xb10 [cifs]\n cifs_demultiplex_thread+0x1148/0x1740 [cifs]\n kthread+0x1cf/0x210" } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 9.8, "baseSeverity": "CRITICAL" }, "scenarios": [ { "lang": "en", "value": "AV:N - The UAF write occurs in the CIFS client kernel thread while copying SMB read-response data received over TCP; a compromised or malicious network filesystem server can supply attacker-controlled payload once a client performs normal buffered read/write on a mounted share.\nAC:L - The bug is deterministic—folio_put(sink) always runs before netfs_wait_for_read() completes—so an attacker who can create a dirty streaming-write folio and then read it reliably triggers the UAF without winning a race.\nPR:N - A remote malicious/compromised SMB/NFS/9p/Ceph server attacker needs no local privileges on the victim; exploitation requires only ordinary file access on an existing network mount, not root or special capabilities.\nUI:N - No special victim interaction beyond normal file read/write operations on a mounted network filesystem; persistent automounts and server-driven workloads make mount-time interaction unnecessary for exploitation.\nS:U - Impact is kernel heap memory corruption within the same kernel security domain; it does not cross VM, container, or IOMMU boundaries.\nC:H - Use-after-free of a page-cache folio enables heap grooming and arbitrary kernel memory read primitives; UAF class bugs are scored High for confidentiality per kernel CNA guidance.\nI:H - The UAF is a write primitive—KASAN reported an 885-byte write of network-supplied data into freed memory—enabling controlled heap corruption and potential code execution.\nA:H - UAF during network I/O can cause kernel oops/panic and denial of service to all workloads on the host; UAF bugs are scored High for availability per kernel CNA guidance." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/netfs/buffered_read.c" ], "versions": [ { "version": "ee4cdf7ba857a894ad1650d6ab77669cbbfa329e", "lessThan": "2a39d49c8d97df8cb8fa80c10859bc1ba7358c6b", "status": "affected", "versionType": "git" }, { "version": "ee4cdf7ba857a894ad1650d6ab77669cbbfa329e", "lessThan": "d4f4bc87c76511cf2532448b0fa40c25e894bd7d", "status": "affected", "versionType": "git" }, { "version": "ee4cdf7ba857a894ad1650d6ab77669cbbfa329e", "lessThan": "412e8bad48967fd34295866636c028befd27d8b9", "status": "affected", "versionType": "git" }, { "version": "ee4cdf7ba857a894ad1650d6ab77669cbbfa329e", "lessThan": "3e5dd91b87a8b1450217b56a336bee315f40da7d", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/netfs/buffered_read.c" ], "versions": [ { "version": "6.12", "status": "affected" }, { "version": "0", "lessThan": "6.12", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.92", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.34", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.0.11", "lessThanOrEqual": "7.0.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1", "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": "6.12", "versionEndExcluding": "6.12.92" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.12", "versionEndExcluding": "6.18.34" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.12", "versionEndExcluding": "7.0.11" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.12", "versionEndExcluding": "7.1" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/2a39d49c8d97df8cb8fa80c10859bc1ba7358c6b" }, { "url": "https://git.kernel.org/stable/c/d4f4bc87c76511cf2532448b0fa40c25e894bd7d" }, { "url": "https://git.kernel.org/stable/c/412e8bad48967fd34295866636c028befd27d8b9" }, { "url": "https://git.kernel.org/stable/c/3e5dd91b87a8b1450217b56a336bee315f40da7d" } ], "title": "netfs: Fix early put of sink folio in netfs_read_gaps()", "x_generator": { "engine": "bippy-1.2.0" } } } }