CVE-2025-21999proc: fix UAF in proc_get_inode()
- 7.8HighCVSS base score
- 0.23%Exploitation in 30 daysEPSS · top 86% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
In the Linux kernel, the following vulnerability has been resolved: proc: fix UAF in proc_get_inode() Fix race between rmmod and /proc/XXX's inode instantiation. The bug is that pde->proc_ops don't belong to /proc, it belongs to a module, therefore dereferencing it after /proc entry has been registered is a bug unless use_pde/unuse_pde() pair has been used. use_pde/unuse_pde can be avoided (2 atomic ops!) because pde->proc_ops never changes so information necessary for inode instantiation can be saved _before_ proc_register() in PDE itself and used later, avoiding pde->proc_ops->... dereference. rmmod lookup sys_delete_module proc_lookup_de pde_get(de); proc_get_inode(dir->i_sb, de); mod->exit() proc_remove remove_proc_subtree proc_entry_rundown(de); free_module(mod); if (S_ISREG(inode->i_mode)) if (de->proc_ops->proc_read_iter) --> As module is already freed, will trigger UAF BUG: unable to handle page fault for address: fffffbfff80a702b PGD 817fc4067 P4D 817fc4067 PUD 817fc0067 PMD 102ef4067 PTE 0 Oops: Oops: 0000 [#1] PREEMPT SMP KASAN PTI CPU: 26 UID: 0 PID: 2667 Comm: ls Tainted: G Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) RIP: 0010:proc_get_inode+0x302/0x6e0 RSP: 0018:ffff88811c837998 EFLAGS: 00010a06 RAX: dffffc0000000000 RBX: ffffffffc0538140 RCX: 0000000000000007 RDX: 1ffffffff80a702b RSI: 0000000000000001 RDI: ffffffffc0538158 RBP: ffff8881299a6000 R08: 0000000067bbe1e5 R09: 1ffff11023906f20 R10: ffffffffb560ca07 R11: ffffffffb2b43a58 R12: ffff888105bb78f0 R13: ffff888100518048 R14: ffff8881299a6004 R15: 0000000000000001 FS: 00007f95b9686840(0000) GS:ffff8883af100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: fffffbfff80a702b CR3: 0000000117dd2000 CR4: 00000000000006f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> proc_lookup_de+0x11f/0x2e0 __lookup_slow+0x188/0x350 walk_component+0x2ab/0x4f0 path_lookupat+0x120/0x660 filename_lookup+0x1ce/0x560 vfs_statx+0xac/0x150 __do_sys_newstat+0x96/0x110 do_syscall_64+0x5f/0x170 entry_SYSCALL_64_after_hwframe+0x76/0x7e [[email protected]: don't do 2 atomic ops on the common path]
Timeline
ID reserved
By Linux
- 3 months later
· 3 months later
Published
- 20 months later
· 20 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| LinuxCNA (assigner) | 3.1 | High7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| CISA-ADPADP (enrichment) | 3.1 | High7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| NVDNVD · Modified | 3.1 | High7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.23% · top 86% of all CVEs (14 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.8.
Affected products
- affected 97a32539b9568bb653683349e5a76d02ff3c3e2c – < eda279586e571b05dff44d48e05f8977ad05855d
- affected 97a32539b9568bb653683349e5a76d02ff3c3e2c – < 4b0b8445b6fd41e6f62ac90547a0ea9d348de3fa
- affected 97a32539b9568bb653683349e5a76d02ff3c3e2c – < 966f331403dc3ed04ff64eaf3930cf1267965e53
- affected 97a32539b9568bb653683349e5a76d02ff3c3e2c – < 63b53198aff2e4e6c5866a4ff73c7891f958ffa4
- affected 97a32539b9568bb653683349e5a76d02ff3c3e2c – < ede3e8ac90ae106f0b29cd759aadebc1568f1308
- affected 97a32539b9568bb653683349e5a76d02ff3c3e2c – < 64dc7c68e040251d9ec6e989acb69f8f6ae4a10b
- affected 97a32539b9568bb653683349e5a76d02ff3c3e2c – < 654b33ada4ab5e926cd9c570196fefa7bec7c1df
- affected 5.6
- unaffected < 5.6
- unaffected 5.10.236 – ≤ 5.10.*
- unaffected 5.15.180 – ≤ 5.15.*
- unaffected 6.1.132 – ≤ 6.1.*
- unaffected 6.6.85 – ≤ 6.6.*
- unaffected 6.12.21 – ≤ 6.12.*
- unaffected 6.13.9 – ≤ 6.13.*
- unaffected 6.14 – ≤ *
References
References11
- https://git.kernel.org/stable/c/eda279586e571b05dff44d48e05f8977ad05855d (opens in a new tab)
- https://git.kernel.org/stable/c/4b0b8445b6fd41e6f62ac90547a0ea9d348de3fa (opens in a new tab)
- https://git.kernel.org/stable/c/966f331403dc3ed04ff64eaf3930cf1267965e53 (opens in a new tab)
- https://git.kernel.org/stable/c/63b53198aff2e4e6c5866a4ff73c7891f958ffa4 (opens in a new tab)
- https://git.kernel.org/stable/c/ede3e8ac90ae106f0b29cd759aadebc1568f1308 (opens in a new tab)
- https://git.kernel.org/stable/c/64dc7c68e040251d9ec6e989acb69f8f6ae4a10b (opens in a new tab)
- https://git.kernel.org/stable/c/654b33ada4ab5e926cd9c570196fefa7bec7c1df (opens in a new tab)
- https://lists.debian.org/debian-lts-announce/2025/05/msg00045.html (opens in a new tab)
- https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html (opens in a new tab)
- https://cert-portal.siemens.com/productcert/html/ssa-019113.html (opens in a new tab)
- https://cert-portal.siemens.com/productcert/html/ssa-457936.html (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2025-9588 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2025-21999)Record last updated .