{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-46055", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-05-13T15:03:33.094Z", "datePublished": "2026-05-27T12:57:13.671Z", "dateUpdated": "2026-08-05T12:29:23.386Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:29:23.386Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\napparmor: Fix string overrun due to missing termination\n\nWhen booting Ubuntu 26.04 with Linux 7.0-rc4 on an ARM64 Qualcomm\nSnapdragon X1 we see a string buffer overrun:\n\nBUG: KASAN: slab-out-of-bounds in aa_dfa_match (security/apparmor/match.c:535)\nRead of size 1 at addr ffff0008901cc000 by task snap-update-ns/2120\n\nCPU: 5 UID: 60578 PID: 2120 Comm: snap-update-ns Not tainted 7.0.0-rc4+ #22 PREEMPTLAZY\nHardware name: LENOVO 83ED/LNVNB161216, BIOS NHCN60WW 09/11/2025\nCall trace:\nshow_stack (arch/arm64/kernel/stacktrace.c:501) (C)\ndump_stack_lvl (lib/dump_stack.c:122)\nprint_report (mm/kasan/report.c:379 mm/kasan/report.c:482)\nkasan_report (mm/kasan/report.c:597)\n__asan_report_load1_noabort (mm/kasan/report_generic.c:378)\naa_dfa_match (security/apparmor/match.c:535)\nmatch_mnt_path_str (security/apparmor/mount.c:244 security/apparmor/mount.c:336)\nmatch_mnt (security/apparmor/mount.c:371)\naa_bind_mount (security/apparmor/mount.c:447 (discriminator 4))\napparmor_sb_mount (security/apparmor/lsm.c:719 (discriminator 1))\nsecurity_sb_mount (security/security.c:1062 (discriminator 31))\npath_mount (fs/namespace.c:4101)\n__arm64_sys_mount (fs/namespace.c:4172 fs/namespace.c:4361 fs/namespace.c:4338 fs/namespace.c:4338)\ninvoke_syscall.constprop.0 (arch/arm64/kernel/syscall.c:35 arch/arm64/kernel/syscall.c:49)\nel0_svc_common.constprop.0 (./include/linux/thread_info.h:142 (discriminator 2) arch/arm64/kernel/syscall.c:140 (discriminator 2))\ndo_el0_svc (arch/arm64/kernel/syscall.c:152)\nel0_svc (arch/arm64/kernel/entry-common.c:80 arch/arm64/kernel/entry-common.c:725)\nel0t_64_sync_handler (arch/arm64/kernel/entry-common.c:744)\nel0t_64_sync (arch/arm64/kernel/entry.S:596)\n\nAllocated by task 2120:\nkasan_save_stack (mm/kasan/common.c:58)\nkasan_save_track (./arch/arm64/include/asm/current.h:19 mm/kasan/common.c:70 mm/kasan/common.c:79)\nkasan_save_alloc_info (mm/kasan/generic.c:571)\n__kasan_kmalloc (mm/kasan/common.c:419)\n__kmalloc_noprof (./include/linux/kasan.h:263 mm/slub.c:5260 mm/slub.c:5272)\naa_get_buffer (security/apparmor/lsm.c:2201)\naa_bind_mount (security/apparmor/mount.c:442)\napparmor_sb_mount (security/apparmor/lsm.c:719 (discriminator 1))\nsecurity_sb_mount (security/security.c:1062 (discriminator 31))\npath_mount (fs/namespace.c:4101)\n__arm64_sys_mount (fs/namespace.c:4172 fs/namespace.c:4361 fs/namespace.c:4338 fs/namespace.c:4338)\ninvoke_syscall.constprop.0 (arch/arm64/kernel/syscall.c:35 arch/arm64/kernel/syscall.c:49)\nel0_svc_common.constprop.0 (./include/linux/thread_info.h:142 (discriminator 2) arch/arm64/kernel/syscall.c:140 (discriminator 2))\ndo_el0_svc (arch/arm64/kernel/syscall.c:152)\nel0_svc (arch/arm64/kernel/entry-common.c:80 arch/arm64/kernel/entry-common.c:725)\nel0t_64_sync_handler (arch/arm64/kernel/entry-common.c:744)\nel0t_64_sync (arch/arm64/kernel/entry.S:596)\n\nThe buggy address belongs to the object at ffff0008901ca000\nwhich belongs to the cache kmalloc-rnd-06-8k of size 8192\nThe buggy address is located 0 bytes to the right of\nallocated 8192-byte region [ffff0008901ca000, ffff0008901cc000)\n\nThe buggy address belongs to the physical page:\npage: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x9101c8\nhead: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:-1 pincount:0\nflags: 0x8000000000000040(head|zone=2)\npage_type: f5(slab)\nraw: 8000000000000040 ffff000800016c40 fffffdffe2d14e10 ffff000800015c70\nraw: 0000000000000000 0000000800010001 00000000f5000000 0000000000000000\nhead: 8000000000000040 ffff000800016c40 fffffdffe2d14e10 ffff000800015c70\nhead: 0000000000000000 0000000800010001 00000000f5000000 0000000000000000\nhead: 8000000000000003 fffffdffe2407201 fffffdffffffffff 00000000ffffffff\nhead: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008\npage dumped because: kasan: bad access detected\n\nMemory state around the buggy address:\nffff0008901cbf00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00\nffff0008\n---truncated---" } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H", "baseScore": 7.1, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The vulnerability is reached through the local `mount(2)` syscall; there is no network-facing path to AppArmor mount mediation.\nAC:L - Every confined directory mount deterministically overwrites the terminator, and the trailing byte from a non-zeroed kmalloc buffer is reliably non-zero (and groomable), so the OOB read is reliably triggered.\nPR:L - Mount requires CAP_SYS_ADMIN, but only namespace-relative — an unprivileged user obtains it via `unshare -Urm`; confinement by a mount-mediating profile is the common Ubuntu/snap default (the actual reporter was unprivileged snap-update-ns).\nUI:N - The attacker performs the directory bind/remount themselves; no action by any other user is required.\nS:U - The out-of-bounds access stays within the kernel's own memory and does not cross into another security authority.\nC:H - Out-of-bounds read of unbounded length (DFA walks until a NUL is found), and the unterminated path is logged via `audit_mount`, leaking adjacent kernel heap contents to the user.\nI:N - The defect is purely a read overrun; the `/` and missing-terminator writes are in-bounds, so no out-of-bounds data modification occurs.\nA:H - The demonstrated behavior is a KASAN slab-out-of-bounds oops; on KASAN/hardened kernels it is a guaranteed crash and can fault when the buffer abuts an unmapped page." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "security/apparmor/path.c" ], "versions": [ { "version": "93d4dbdc8da0b8a3ba86f4a08868084f8da872e1", "lessThan": "4b877ef27adc8ec187b0418629169856e7264e01", "status": "affected", "versionType": "git" }, { "version": "93d4dbdc8da0b8a3ba86f4a08868084f8da872e1", "lessThan": "828bf7929bedcb79b560b5b4e44f22abee07d31b", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "security/apparmor/path.c" ], "versions": [ { "version": "7.0", "status": "affected" }, { "version": "0", "lessThan": "7.0", "status": "unaffected", "versionType": "semver" }, { "version": "7.0.4", "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": "7.0", "versionEndExcluding": "7.0.4" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "7.0", "versionEndExcluding": "7.1" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/4b877ef27adc8ec187b0418629169856e7264e01" }, { "url": "https://git.kernel.org/stable/c/828bf7929bedcb79b560b5b4e44f22abee07d31b" } ], "title": "apparmor: Fix string overrun due to missing termination", "x_generator": { "engine": "bippy-1.2.0" } } } }