{ "schemaVersion": 1, "attribution": [ { "source": "CISA Known Exploited Vulnerabilities", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog", "licence": "US government work" }, { "source": "GitHub Advisory Database", "url": "https://github.com/advisories", "licence": "CC BY 4.0" }, { "source": "Have I Been Pwned", "url": "https://haveibeenpwned.com/", "licence": "CC BY 4.0" }, { "source": "CVE Program (CVE records)", "url": "https://www.cve.org/Legal/TermsOfUse", "licence": "CVE Terms of Use", "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.", "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy." }, { "source": "FIRST EPSS", "url": "https://www.first.org/epss/", "licence": "free to use; FIRST requests attribution" } ], "record": { "id": "CVE-2025-38517", "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2025-38517", "idYear": 2025, "status": "PUBLISHED", "publishedAt": "2025-08-16T10:55:04.217Z", "updatedAt": "2026-05-11T21:29:33.070Z", "importedAt": "2026-10-24T01:57:34.152Z", "snapshot": { "id": "cve_2026-10-24_midnight_baseline", "at": "2026-10-24T00:00:00.000Z", "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z" }, "facts": { "title": "lib/alloc_tag: do not acquire non-existent lock in alloc_tag_top_users()", "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nlib/alloc_tag: do not acquire non-existent lock in alloc_tag_top_users()\n\nalloc_tag_top_users() attempts to lock alloc_tag_cttype->mod_lock even\nwhen the alloc_tag_cttype is not allocated because:\n\n 1) alloc tagging is disabled because mem profiling is disabled\n (!alloc_tag_cttype)\n 2) alloc tagging is enabled, but not yet initialized (!alloc_tag_cttype)\n 3) alloc tagging is enabled, but failed initialization\n (!alloc_tag_cttype or IS_ERR(alloc_tag_cttype))\n\nIn all cases, alloc_tag_cttype is not allocated, and therefore\nalloc_tag_top_users() should not attempt to acquire the semaphore.\n\nThis leads to a crash on memory allocation failure by attempting to\nacquire a non-existent semaphore:\n\n Oops: general protection fault, probably for non-canonical address 0xdffffc000000001b: 0000 [#3] SMP KASAN NOPTI\n KASAN: null-ptr-deref in range [0x00000000000000d8-0x00000000000000df]\n CPU: 2 UID: 0 PID: 1 Comm: systemd Tainted: G D 6.16.0-rc2 #1 VOLUNTARY\n Tainted: [D]=DIE\n Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014\n RIP: 0010:down_read_trylock+0xaa/0x3b0\n Code: d0 7c 08 84 d2 0f 85 a0 02 00 00 8b 0d df 31 dd 04 85 c9 75 29 48 b8 00 00 00 00 00 fc ff df 48 8d 6b 68 48 89 ea 48 c1 ea 03 <80> 3c 02 00 0f 85 88 02 00 00 48 3b 5b 68 0f 85 53 01 00 00 65 ff\n RSP: 0000:ffff8881002ce9b8 EFLAGS: 00010016\n RAX: dffffc0000000000 RBX: 0000000000000070 RCX: 0000000000000000\n RDX: 000000000000001b RSI: 000000000000000a RDI: 0000000000000070\n RBP: 00000000000000d8 R08: 0000000000000001 R09: ffffed107dde49d1\n R10: ffff8883eef24e8b R11: ffff8881002cec20 R12: 1ffff11020059d37\n R13: 00000000003fff7b R14: ffff8881002cec20 R15: dffffc0000000000\n FS: 00007f963f21d940(0000) GS:ffff888458ca6000(0000) knlGS:0000000000000000\n CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n CR2: 00007f963f5edf71 CR3: 000000010672c000 CR4: 0000000000350ef0\n Call Trace:\n \n codetag_trylock_module_list+0xd/0x20\n alloc_tag_top_users+0x369/0x4b0\n __show_mem+0x1cd/0x6e0\n warn_alloc+0x2b1/0x390\n __alloc_frozen_pages_noprof+0x12b9/0x21a0\n alloc_pages_mpol+0x135/0x3e0\n alloc_slab_page+0x82/0xe0\n new_slab+0x212/0x240\n ___slab_alloc+0x82a/0xe00\n \n\nAs David Wang points out, this issue became easier to trigger after commit\n780138b12381 (\"alloc_tag: check mem_profiling_support in alloc_tag_init\").\n\nBefore the commit, the issue occurred only when it failed to allocate and\ninitialize alloc_tag_cttype or if a memory allocation fails before\nalloc_tag_init() is called. After the commit, it can be easily triggered\nwhen memory profiling is compiled but disabled at boot.\n\nTo properly determine whether alloc_tag_init() has been called and its\ndata structures initialized, verify that alloc_tag_cttype is a valid\npointer before acquiring the semaphore. If the variable is NULL or an\nerror value, it has not been properly initialized. In such a case, just\nskip and do not attempt to acquire the semaphore.\n\n[harry.yoo@oracle.com: v3]", "affected": [ { "vendor": "Linux", "product": "Linux", "defaultStatus": "unaffected", "versions": [ { "version": "1438d349d16b78d88f9e978a4a5496f078c8191b", "status": "affected", "versionType": "git", "lessThan": "febc0b5dbabda414565bdfaaaa59d26f787d5fe7" }, { "version": "1438d349d16b78d88f9e978a4a5496f078c8191b", "status": "affected", "versionType": "git", "lessThan": "22bf79c0c2301b6e15a688220284b147774d277e" }, { "version": "1438d349d16b78d88f9e978a4a5496f078c8191b", "status": "affected", "versionType": "git", "lessThan": "99af22cd34688cc0d535a1919e0bea4cbc6c1ea1" } ] }, { "vendor": "Linux", "product": "Linux", "defaultStatus": "affected", "versions": [ { "version": "6.10", "status": "affected" }, { "version": "0", "status": "unaffected", "versionType": "semver", "lessThan": "6.10" }, { "version": "6.12.39", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.12.*" }, { "version": "6.15.7", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.15.*" }, { "version": "6.16", "status": "unaffected", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*" } ] } ] } } }