{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2025-21999", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-12-29T08:45:45.801Z", "datePublished": "2025-04-03T07:19:03.040Z", "dateUpdated": "2026-08-05T11:55:55.058Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T11:55:55.058Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nproc: fix UAF in proc_get_inode()\n\nFix race between rmmod and /proc/XXX's inode instantiation.\n\nThe bug is that pde->proc_ops don't belong to /proc, it belongs to a\nmodule, therefore dereferencing it after /proc entry has been registered\nis a bug unless use_pde/unuse_pde() pair has been used.\n\nuse_pde/unuse_pde can be avoided (2 atomic ops!) because pde->proc_ops\nnever changes so information necessary for inode instantiation can be\nsaved _before_ proc_register() in PDE itself and used later, avoiding\npde->proc_ops->... dereference.\n\n rmmod lookup\nsys_delete_module\n proc_lookup_de\n\t\t\t pde_get(de);\n\t\t\t proc_get_inode(dir->i_sb, de);\n mod->exit()\n proc_remove\n remove_proc_subtree\n proc_entry_rundown(de);\n free_module(mod);\n\n if (S_ISREG(inode->i_mode))\n\t if (de->proc_ops->proc_read_iter)\n --> As module is already freed, will trigger UAF\n\nBUG: unable to handle page fault for address: fffffbfff80a702b\nPGD 817fc4067 P4D 817fc4067 PUD 817fc0067 PMD 102ef4067 PTE 0\nOops: Oops: 0000 [#1] PREEMPT SMP KASAN PTI\nCPU: 26 UID: 0 PID: 2667 Comm: ls Tainted: G\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996)\nRIP: 0010:proc_get_inode+0x302/0x6e0\nRSP: 0018:ffff88811c837998 EFLAGS: 00010a06\nRAX: dffffc0000000000 RBX: ffffffffc0538140 RCX: 0000000000000007\nRDX: 1ffffffff80a702b RSI: 0000000000000001 RDI: ffffffffc0538158\nRBP: ffff8881299a6000 R08: 0000000067bbe1e5 R09: 1ffff11023906f20\nR10: ffffffffb560ca07 R11: ffffffffb2b43a58 R12: ffff888105bb78f0\nR13: ffff888100518048 R14: ffff8881299a6004 R15: 0000000000000001\nFS: 00007f95b9686840(0000) GS:ffff8883af100000(0000) knlGS:0000000000000000\nCS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\nCR2: fffffbfff80a702b CR3: 0000000117dd2000 CR4: 00000000000006f0\nDR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000\nDR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400\nCall Trace:\n \n proc_lookup_de+0x11f/0x2e0\n __lookup_slow+0x188/0x350\n walk_component+0x2ab/0x4f0\n path_lookupat+0x120/0x660\n filename_lookup+0x1ce/0x560\n vfs_statx+0xac/0x150\n __do_sys_newstat+0x96/0x110\n do_syscall_64+0x5f/0x170\n entry_SYSCALL_64_after_hwframe+0x76/0x7e\n\n[adobriyan@gmail.com: don't do 2 atomic ops on the common path]" } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The vulnerable path is reached through ordinary local syscalls (stat/open/newstat) on paths under /proc, as shown by the commit's own trace from `ls` via `__do_sys_newstat` → `path_lookupat` → `proc_lookup_de` → `proc_get_inode`. No network protocol handling is involved.\nAC:L - The attacker fully controls their side of the race and can hold the window open continuously — `/proc/net` entries use `proc_net_dentry_ops` whose `.d_revalidate` always returns 0, so every single access re-runs `proc_lookup_de()`/`proc_get_inode()`, and fresh procfs mounts or netns via `unshare -Ur` defeat any dcache caching. On the realistic deployment targets (Android, embedded, automotive) module load/unload cycles are frequent and user-inducible via device/radio state changes, so no condition requires attacker-unattainable luck.\nPR:L - Triggering the vulnerable dereference requires only the ability to look up a path under /proc, which is mode 0555 and open to any unprivileged local user; no capability is checked anywhere on the lookup path. Unprivileged users can additionally use user namespaces to obtain fresh procfs/netns instances and to autoload modules that register `/proc/net` entries.\nUI:N - The attacker's exploitation loop is entirely self-driven — a continuous stat() loop on the target /proc entry — and requires no victim to open a file, mount a filesystem, or otherwise participate.\nS:U - The use-after-free occurs in kernel memory and its consequences are confined to the kernel's own security authority; there is no crossing of a VM, IOMMU, or sandbox boundary.\nC:H - This is a use-after-free on freed module memory; once the vmalloc/execmem region is reclaimed and re-populated (e.g. by a subsequent module load), the stale read feeds attacker-influenceable data into inode setup, and UAF primitives of this class are leveraged for kernel memory disclosure.\nI:H - The UAF causes the kernel to select `i_fop` based on freed, potentially reallocated memory, yielding a stale-object/type-confusion condition on the instantiated inode; use-after-free on kernel structures is exploitable via heap grooming for control-flow-relevant corruption.\nA:H - The commit documents an unrecoverable oops — \"BUG: unable to handle page fault for address: fffffbfff80a702b … Oops: 0000 [#1] PREEMPT SMP KASAN PTI\" at `proc_get_inode+0x302` — and the attacker can retrigger it at will with a stat() loop, causing kernel crash/denial of service." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/proc/generic.c", "fs/proc/inode.c", "fs/proc/internal.h", "include/linux/proc_fs.h" ], "versions": [ { "version": "97a32539b9568bb653683349e5a76d02ff3c3e2c", "lessThan": "eda279586e571b05dff44d48e05f8977ad05855d", "status": "affected", "versionType": "git" }, { "version": "97a32539b9568bb653683349e5a76d02ff3c3e2c", "lessThan": "4b0b8445b6fd41e6f62ac90547a0ea9d348de3fa", "status": "affected", "versionType": "git" }, { "version": "97a32539b9568bb653683349e5a76d02ff3c3e2c", "lessThan": "966f331403dc3ed04ff64eaf3930cf1267965e53", "status": "affected", "versionType": "git" }, { "version": "97a32539b9568bb653683349e5a76d02ff3c3e2c", "lessThan": "63b53198aff2e4e6c5866a4ff73c7891f958ffa4", "status": "affected", "versionType": "git" }, { "version": "97a32539b9568bb653683349e5a76d02ff3c3e2c", "lessThan": "ede3e8ac90ae106f0b29cd759aadebc1568f1308", "status": "affected", "versionType": "git" }, { "version": "97a32539b9568bb653683349e5a76d02ff3c3e2c", "lessThan": "64dc7c68e040251d9ec6e989acb69f8f6ae4a10b", "status": "affected", "versionType": "git" }, { "version": "97a32539b9568bb653683349e5a76d02ff3c3e2c", "lessThan": "654b33ada4ab5e926cd9c570196fefa7bec7c1df", "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/proc/generic.c", "fs/proc/inode.c", "fs/proc/internal.h", "include/linux/proc_fs.h" ], "versions": [ { "version": "5.6", "status": "affected" }, { "version": "0", "lessThan": "5.6", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.236", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.180", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.132", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.85", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.21", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.13.9", "lessThanOrEqual": "6.13.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.14", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ 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"https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html" } ], "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2025-11-03T19:40:42.019Z" } }, { "x_adpType": "supplier", "providerMetadata": { "orgId": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e", "shortName": "siemens-SADP", "dateUpdated": "2026-07-14T12:40:36.768Z" }, "affected": [ { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.6", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.6", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.6", "lessThan": "*", "versionType": "custom" } ], 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