{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-68169", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-30T09:28:09.372Z", "datePublished": "2026-08-10T11:59:38.177Z", "dateUpdated": "2026-08-23T12:46:03.401Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-23T12:46:03.401Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmptcp: pm: userspace: fix use-after-free in get_local_id\n\nIn mptcp_pm_userspace_get_local_id(), the address entry is looked up under\nspinlock, but its id is read after dropping the lock. A concurrent deletion\ncan free the entry between the unlock and the read, leading to UAF.\n\nThe race window is narrow. It was reproduced only with a locally\nconstructed stress test that repeatedly overlaps an MP_JOIN SYN with a\nMPTCP_PM_CMD_SUBFLOW_DESTROY request.\n\nHowever, the KASAN report below confirms that the race is reachable:\n\n [ 666.319376] BUG: KASAN: slab-use-after-free in mptcp_userspace_pm_get_local_id+0x1dc/0x1f0\n [ 666.319386] Read of size 1 at addr ffff888124845610 by task swapper/0/0\n ...\n [ 666.319401] Call Trace:\n [ 666.319405] \n [ 666.319408] dump_stack_lvl+0x53/0x70\n [ 666.319412] print_address_description.constprop.0+0x2c/0x3b0\n [ 666.319418] print_report+0xbe/0x2b0\n [ 666.319421] ? mptcp_userspace_pm_get_local_id+0x1dc/0x1f0\n [ 666.319423] kasan_report+0xce/0x100\n [ 666.319426] ? mptcp_userspace_pm_get_local_id+0x1dc/0x1f0\n [ 666.319429] mptcp_userspace_pm_get_local_id+0x1dc/0x1f0\n [ 666.319433] mptcp_pm_get_local_id+0x371/0x440\n ...\n [ 666.319821] Allocated by task 45539:\n [ 666.319844] kasan_save_stack+0x33/0x60\n [ 666.319855] kasan_save_track+0x14/0x30\n [ 666.319858] __kasan_kmalloc+0x8f/0xa0\n [ 666.319863] __kmalloc_noprof+0x1e7/0x520\n [ 666.319867] sock_kmalloc+0xdf/0x130\n [ 666.319885] sock_kmemdup+0x1b/0x40\n [ 666.319888] mptcp_userspace_pm_append_new_local_addr+0x261/0x500\n [ 666.319910] mptcp_pm_nl_announce_doit+0x16a/0x610\n ...\n [ 666.319967] Freed by task 45560:\n [ 666.319988] kasan_save_stack+0x33/0x60\n [ 666.319991] kasan_save_track+0x14/0x30\n [ 666.319994] kasan_save_free_info+0x3b/0x60\n [ 666.319998] __kasan_slab_free+0x43/0x70\n [ 666.320000] kfree+0x166/0x440\n [ 666.320003] sock_kfree_s+0x1d/0x50\n [ 666.320007] mptcp_userspace_pm_delete_local_addr.isra.0+0x157/0x200\n [ 666.320011] mptcp_pm_nl_subflow_destroy_doit+0x51d/0xea0\n\nFix by copying the id into a local variable while still holding the lock,\nand use -1 as a \"not found\" sentinel." } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/mptcp/pm_userspace.c" ], "versions": [ { "version": "e373bfc8ec3d6496ec7e11dd7f4d087a44b1009a", "lessThan": "8ce48d2879aafc0e7a6f8bfc3613c0ba979ec6f5", "status": "affected", "versionType": "git" }, { "version": "ed34dfa19ddbd1e4c85a73636f8cba0211025ea4", "lessThan": "d2c3760b45f2f481a4dd4c5adef4a29dfabd948f", "status": "affected", "versionType": "git" }, { "version": "f012d796a6de662692159c539689e47e662853a8", "lessThan": "31ce5af66891f79998fb2e8b8df08e3c98fd72e3", "status": "affected", "versionType": "git" }, { "version": "f012d796a6de662692159c539689e47e662853a8", "lessThan": "d64f6c02495f3fad674038cfa7ec049671b59e7b", "status": "affected", "versionType": "git" }, { "version": "f012d796a6de662692159c539689e47e662853a8", "lessThan": "40dde4b5d98279471a70e5c8bb713182738c00d9", "status": "affected", "versionType": "git" }, { "version": "f012d796a6de662692159c539689e47e662853a8", "lessThan": "9bc6d5e4ca9f3cbb41d43400b3a31cb0403796c9", "status": "affected", "versionType": "git" }, { "version": "005a3ad289eb604216dcaa03646de36cb08624a0", "status": "affected", "versionType": "git" }, { "version": "6.1.79", "lessThan": "6.1.184", "status": "affected", "versionType": "semver" }, { "version": "6.6.18", "lessThan": "6.6.151", "status": "affected", "versionType": "semver" }, { "version": "6.7.6", "lessThan": "6.8", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/mptcp/pm_userspace.c" ], "versions": [ { "version": "6.8", "status": "affected" }, { "version": "0", "lessThan": "6.8", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.184", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.151", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.103", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.42", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.6", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2", "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": "6.1.79", "versionEndExcluding": "6.1.184" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.6.18", "versionEndExcluding": "6.6.151" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.8", "versionEndExcluding": "6.12.103" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.8", "versionEndExcluding": "6.18.42" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.8", "versionEndExcluding": "7.1.6" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.8", "versionEndExcluding": "7.2" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.7.6" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/8ce48d2879aafc0e7a6f8bfc3613c0ba979ec6f5" }, { "url": "https://git.kernel.org/stable/c/d2c3760b45f2f481a4dd4c5adef4a29dfabd948f" }, { "url": "https://git.kernel.org/stable/c/31ce5af66891f79998fb2e8b8df08e3c98fd72e3" }, { "url": "https://git.kernel.org/stable/c/d64f6c02495f3fad674038cfa7ec049671b59e7b" }, { "url": "https://git.kernel.org/stable/c/40dde4b5d98279471a70e5c8bb713182738c00d9" }, { "url": "https://git.kernel.org/stable/c/9bc6d5e4ca9f3cbb41d43400b3a31cb0403796c9" } ], "title": "mptcp: pm: userspace: fix use-after-free in get_local_id", "x_generator": { "engine": "bippy-1.2.0" } } } }