{"id":"CVE-2025-21999","revision":"46526f6f3de846c38026e5911cf68ddf","records":[{"revision":"46526f6f3de846c38026e5911cf68ddf","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2025-21999","aliases":[],"title":"proc: fix UAF in proc_get_inode()","description":"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]","state":0,"publishedAt":"2025-04-03T07:19:03.04+00:00","modifiedAt":"2026-10-15T01:05:17.437+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n \"product\": \"Linux\",\n \"vendor\": \"Linux\",\n \"defaultStatus\": \"unaffected\",\n \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n \"programFiles\": [\n \"fs/proc/generic.c\",\n \"fs/proc/inode.c\",\n \"fs/proc/internal.h\",\n \"include/linux/proc_fs.h\"\n ],\n \"versions\": [\n {\n \"version\": \"97a32539b9568bb653683349e5a76d02ff3c3e2c\",\n \"lessThan\": \"eda279586e571b05dff44d48e05f8977ad05855d\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"97a32539b9568bb653683349e5a76d02ff3c3e2c\",\n \"lessThan\": \"4b0b8445b6fd41e6f62ac90547a0ea9d348de3fa\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"97a32539b9568bb653683349e5a76d02ff3c3e2c\",\n \"lessThan\": \"966f331403dc3ed04ff64eaf3930cf1267965e53\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"97a32539b9568bb653683349e5a76d02ff3c3e2c\",\n \"lessThan\": \"63b53198aff2e4e6c5866a4ff73c7891f958ffa4\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"97a32539b9568bb653683349e5a76d02ff3c3e2c\",\n \"lessThan\": \"ede3e8ac90ae106f0b29cd759aadebc1568f1308\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"97a32539b9568bb653683349e5a76d02ff3c3e2c\",\n \"lessThan\": \"64dc7c68e040251d9ec6e989acb69f8f6ae4a10b\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"97a32539b9568bb653683349e5a76d02ff3c3e2c\",\n \"lessThan\": \"654b33ada4ab5e926cd9c570196fefa7bec7c1df\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n }\n ]\n }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n \"product\": \"Linux\",\n \"vendor\": \"Linux\",\n \"defaultStatus\": \"affected\",\n \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n \"programFiles\": [\n \"fs/proc/generic.c\",\n \"fs/proc/inode.c\",\n \"fs/proc/internal.h\",\n \"include/linux/proc_fs.h\"\n ],\n \"versions\": [\n {\n \"version\": \"5.6\",\n \"status\": \"affected\"\n },\n {\n \"version\": \"0\",\n \"lessThan\": \"5.6\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"5.10.236\",\n \"lessThanOrEqual\": \"5.10.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"5.15.180\",\n \"lessThanOrEqual\": \"5.15.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.1.132\",\n \"lessThanOrEqual\": \"6.1.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.6.85\",\n \"lessThanOrEqual\": \"6.6.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.12.21\",\n \"lessThanOrEqual\": \"6.12.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.13.9\",\n \"lessThanOrEqual\": \"6.13.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.14\",\n \"lessThanOrEqual\": \"*\",\n \"status\": \"unaffected\",\n \"versionType\": \"original_commit_for_fix\"\n }\n ]\n }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8,"severity":"HIGH"}],"references":["https://git.kernel.org/stable/c/eda279586e571b05dff44d48e05f8977ad05855d","https://git.kernel.org/stable/c/4b0b8445b6fd41e6f62ac90547a0ea9d348de3fa","https://git.kernel.org/stable/c/966f331403dc3ed04ff64eaf3930cf1267965e53","https://git.kernel.org/stable/c/63b53198aff2e4e6c5866a4ff73c7891f958ffa4","https://git.kernel.org/stable/c/ede3e8ac90ae106f0b29cd759aadebc1568f1308","https://git.kernel.org/stable/c/64dc7c68e040251d9ec6e989acb69f8f6ae4a10b","https://git.kernel.org/stable/c/654b33ada4ab5e926cd9c570196fefa7bec7c1df"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2025-21999","license":"CVE Program Terms of Use","key":"cve-program:CVE-2025-21999","identifiers":["CVE-2025-21999"]},"retained":false,"historicalAffected":[]}],"coverage":[]}