{"id":"CVE-2026-64048","summary":"net/smc: reject CHID-0 ACCEPT that matches an empty ism_dev slot","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/smc: reject CHID-0 ACCEPT that matches an empty ism_dev slot\n\nOn the SMC-D client, slot 0 of ini-\u003eism_dev[]/ini-\u003eism_chid[] is\nreserved for an SMC-Dv1 device. smc_find_ism_v2_device_clnt()\npopulates V2 entries starting at index 1, so when no V1 device is\nselected slot 0 is left in its kzalloc()'ed state with ism_dev[0] ==\nNULL and ism_chid[0] == 0.\n\nsmc_v2_determine_accepted_chid() then matches the peer's CHID against\nthe array starting from index 0 using the CHID alone. A malicious\npeer replying to a SMC-Dv2-only proposal with d1.chid == 0 matches\nthe empty slot, ini-\u003eism_selected becomes 0, and the subsequent\nism_dev[0]-\u003elgr_lock dereference in smc_conn_create() faults at\noffsetof(struct smcd_dev, lgr_lock) == 0x68:\n\n  BUG: KASAN: null-ptr-deref in _raw_spin_lock_bh+0x79/0xe0\n  Write of size 4 at addr 0000000000000068 by task exploit/144\n  Call Trace:\n   _raw_spin_lock_bh\n   smc_conn_create (net/smc/smc_core.c:1997)\n   __smc_connect (net/smc/af_smc.c:1447)\n   smc_connect (net/smc/af_smc.c:1720)\n   __sys_connect\n   __x64_sys_connect\n   do_syscall_64\n\nRequire ism_dev[i] to be non-NULL before accepting a CHID match.","modified":"2026-07-22T05:29:39.565609727Z","published":"2026-07-19T15:39:32.664Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64048.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/277740023def559a4a2ddc3e8e784ee37a0f16a9"},{"type":"WEB","url":"https://git.kernel.org/stable/c/53eb7bd09aace72fa17510d80e0caf5ca058c231"},{"type":"WEB","url":"https://git.kernel.org/stable/c/65edb3b0822cfe5041be8fbabebd57e2e5ad9f4e"},{"type":"WEB","url":"https://git.kernel.org/stable/c/6927cacf2b10d4fa80c1a2d407512ef9397c59c6"},{"type":"WEB","url":"https://git.kernel.org/stable/c/afa9036b8c9963947b487c36e332df6a42c96fcb"},{"type":"WEB","url":"https://git.kernel.org/stable/c/d38ba387244e5c5f7db3e11ea98bc2c7beccb0c0"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64048.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-64048"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"a7c9c5f4af7f6098da68705fc5d86565d0728ef7"},{"fixed":"6927cacf2b10d4fa80c1a2d407512ef9397c59c6"},{"fixed":"d38ba387244e5c5f7db3e11ea98bc2c7beccb0c0"},{"fixed":"53eb7bd09aace72fa17510d80e0caf5ca058c231"},{"fixed":"afa9036b8c9963947b487c36e332df6a42c96fcb"},{"fixed":"65edb3b0822cfe5041be8fbabebd57e2e5ad9f4e"},{"fixed":"277740023def559a4a2ddc3e8e784ee37a0f16a9"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64048.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.10.0"},{"fixed":"6.1.175"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.142"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.92"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.34"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.0.11"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64048.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}