{"id":"CVE-2026-64190","title":"net: team: fix NULL pointer dereference in team_xmit during mode change","summary":"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->ops with memset() before restoring\nsafe dummy handlers via te…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 3d249d4ca7d0ed6629a135ea1ea21c72286c0d80 < 9486377e5e971988a3add171c398eb654a866fab","Linux >= 3d249d4ca7d0ed6629a135ea1ea21c72286c0d80 < cde5c7f0286c4203d0abc7248201542aa8bf33bb","Linux >= 3d249d4ca7d0ed6629a135ea1ea21c72286c0d80 < 03e9405c518c4d61f28079492f252d6d4e2bac5c","Linux >= 3d249d4ca7d0ed6629a135ea1ea21c72286c0d80 < 25fe708bbc59289d3d1ea4b126fbc1b460a072a5","Linux 3.3"],"published":"2026-07-20","updated":"2026-10-21","sourceUpdated":"2026-10-21T12:43:10.158Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-64190","references":[{"url":"https://git.kernel.org/stable/c/9486377e5e971988a3add171c398eb654a866fab"},{"url":"https://git.kernel.org/stable/c/cde5c7f0286c4203d0abc7248201542aa8bf33bb"},{"url":"https://git.kernel.org/stable/c/03e9405c518c4d61f28079492f252d6d4e2bac5c"},{"url":"https://git.kernel.org/stable/c/25fe708bbc59289d3d1ea4b126fbc1b460a072a5"}],"tags":["cve.org"],"epss":0.00104,"epssPercentile":0.00962,"ingestedAt":"2026-10-21T12:48:53.609Z","slug":"CVE-2026-64190","body":"## Overview\n\nIn 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->ops with memset() before restoring\nsafe dummy handlers via team_adjust_ops(). A concurrent team_xmit()\nrunning under RCU on another CPU can read team->ops.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.\n\n## Affected\n\n- `Linux >= 3d249d4ca7d0ed6629a135ea1ea21c72286c0d80 < 9486377e5e971988a3add171c398eb654a866fab`\n- `Linux >= 3d249d4ca7d0ed6629a135ea1ea21c72286c0d80 < cde5c7f0286c4203d0abc7248201542aa8bf33bb`\n- `Linux >= 3d249d4ca7d0ed6629a135ea1ea21c72286c0d80 < 03e9405c518c4d61f28079492f252d6d4e2bac5c`\n- `Linux >= 3d249d4ca7d0ed6629a135ea1ea21c72286c0d80 < 25fe708bbc59289d3d1ea4b126fbc1b460a072a5`\n- `Linux 3.3`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}