{"id":"CVE-2026-64190","summary":"net: team: fix NULL pointer dereference in team_xmit during mode change","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: team: fix NULL pointer dereference in team_xmit during mode change\n\n__team_change_mode() clears team-\u003eops with memset() before restoring\nsafe dummy handlers via team_adjust_ops(). A concurrent team_xmit()\nrunning under RCU on another CPU can read team-\u003eops.transmit during\nthis window and call a NULL function pointer, crashing the kernel.\n\nThe race requires a mode change (CAP_NET_ADMIN) concurrent with\ntransmit on the team device.\n\n BUG: kernel NULL pointer dereference, address: 0000000000000000\n Oops: 0010 [#1] SMP KASAN NOPTI\n RIP: 0010:0x0\n Call Trace:\n  team_xmit (drivers/net/team/team_core.c:1853)\n  dev_hard_start_xmit (net/core/dev.c:3904)\n  __dev_queue_xmit (net/core/dev.c:4871)\n  packet_sendmsg (net/packet/af_packet.c:3109)\n  __sys_sendto (net/socket.c:2265)\n\nThe original code assumed that no ports means no traffic, so mode\nchanges could freely memset()/memcpy() the ops.  AF_PACKET with\nforced carrier breaks that assumption.\n\nPrevent the race instead of making it safe: replace memset()/memcpy()\nwith per-field updates that never touch transmit or receive.  Those\ntwo handlers are managed solely by team_adjust_ops(), which already\ninstalls dummies when tx_en_port_count == 0 (always true during mode\nchange since no ports are present).  WRITE_ONCE/READ_ONCE prevent\nstore/load tearing on the handler pointers.\n\nsynchronize_net() before exit_op() drains in-flight readers that may\nstill reference old mode state from before port removal switched the\nhandlers to dummies.","modified":"2026-07-22T05:33:07.214481835Z","published":"2026-07-20T16:27:48.314Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64190.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/03e9405c518c4d61f28079492f252d6d4e2bac5c"},{"type":"WEB","url":"https://git.kernel.org/stable/c/25fe708bbc59289d3d1ea4b126fbc1b460a072a5"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64190.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-64190"},{"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":"3d249d4ca7d0ed6629a135ea1ea21c72286c0d80"},{"fixed":"03e9405c518c4d61f28079492f252d6d4e2bac5c"},{"fixed":"25fe708bbc59289d3d1ea4b126fbc1b460a072a5"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64190.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"3.3.0"},{"fixed":"6.18.35"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64190.json"}}],"schema_version":"1.7.5"}