In the Linux kernel, the following vulnerability has been resolved: net: team: fix NULL pointer dereference in team_xmit during mode change __team_change_mode() clears team->ops with memset() before restoring safe dummy handlers via team_adjust_ops(). A concurrent team_xmit() running under RCU on another CPU can read team->ops.transmit during this window and call a NULL function pointer, crashing the kernel. The race requires a mode change (CAP_NET_ADMIN) concurrent with transmit on the team device. BUG: kernel NULL pointer dereference, address: 0000000000000000 Oops: 0010 [#1] SMP KASAN NOPTI RIP: 0010:0x0 Call Trace: team_xmit (drivers/net/team/team_core.c:1853) dev_hard_start_xmit (net/core/dev.c:3904) __dev_queue_xmit (net/core/dev.c:4871) packet_sendmsg (net/packet/af_packet.c:3109) __sys_sendto (net/socket.c:2265) The original code assumed that no ports means no traffic, so mode changes could freely memset()/memcpy() the ops. AF_PACKET with forced carrier breaks that assumption. Prevent the race instead of making it safe: replace memset()/memcpy() with per-field updates that never touch transmit or receive. Those two handlers are managed solely by team_adjust_ops(), which already installs dummies when tx_en_port_count == 0 (always true during mode change since no ports are present). WRITE_ONCE/READ_ONCE prevent store/load tearing on the handler pointers. synchronize_net() before exit_op() drains in-flight readers that may still reference old mode state from before port removal switched the handlers to dummies.

The Unity Linux 20 host has a package installed that is affected by a vulnerability as referenced in the UTSA-2026-073357 advisory.

    In the Linux kernel, the following vulnerability has been resolved:

    net: team: fix NULL pointer dereference in team_xmit during mode change

    __team_change_mode() clears team->ops with memset() before restoring     safe dummy handlers via team_adjust_ops(). A concurrent team_xmit()     running under RCU on another CPU can read team->ops.transmit during     this window and call a NULL function pointer, crashing the kernel.

    The race requires a mode change (CAP_NET_ADMIN) concurrent with     transmit on the team device.

     BUG: kernel NULL pointer dereference, address: 0000000000000000      Oops: 0010 [#1] SMP KASAN NOPTI      RIP: 0010:0x0      Call Trace:
      team_xmit (drivers/net/team/team_core.c:1853)       dev_hard_start_xmit (net/core/dev.c:3904)
      __dev_queue_xmit (net/core/dev.c:4871)       packet_sendmsg (net/packet/af_packet.c:3109)
      __sys_sendto (net/socket.c:2265)

    The original code assumed that no ports means no traffic, so mode     changes could freely memset()/memcpy() the ops.  AF_PACKET with     forced carrier breaks that assumption.

    Prevent the race instead of making it safe: replace memset()/memcpy()     with per-field updates that never touch transmit or receive.  Those     two handlers are managed solely by team_adjust_ops(), which already     installs dummies when tx_en_port_count == 0 (always true during mode     change since no ports are present).  WRITE_ONCE/READ_ONCE prevent     store/load tearing on the handler pointers.

    synchronize_net() before exit_op() drains in-flight readers that may     still reference old mode state from before port removal switched the     handlers to dummies.

Tenable has extracted the preceding description block directly from the Unity Linux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - net: team: fix NULL pointer dereference in team_xmit during mode change __team_change_mode() clears     team->ops with memset() before restoring safe dummy handlers via team_adjust_ops(). A concurrent     team_xmit() running under RCU on another CPU can read team->ops.transmit during this window and call a     NULL function pointer, crashing the kernel. The race requires a mode change (CAP_NET_ADMIN) concurrent     with transmit on the team device. BUG: kernel NULL pointer dereference, address: 0000000000000000 Oops:
    0010 [#1] SMP KASAN NOPTI RIP: 0010:0x0 Call Trace: team_xmit (drivers/net/team/team_core.c:1853)     dev_hard_start_xmit (net/core/dev.c:3904) __dev_queue_xmit (net/core/dev.c:4871) packet_sendmsg     (net/packet/af_packet.c:3109) __sys_sendto (net/socket.c:2265) The original code assumed that no ports     means no traffic, so mode changes could freely memset()/memcpy() the ops. AF_PACKET with forced carrier     breaks that assumption. Prevent the race instead of making it safe: replace memset()/memcpy() with per-     field updates that never touch transmit or receive. Those two handlers are managed solely by     team_adjust_ops(), which already installs dummies when tx_en_port_count == 0 (always true during mode     change since no ports are present). WRITE_ONCE/READ_ONCE prevent store/load tearing on the handler     pointers. synchronize_net() before exit_op() drains in-flight readers that may still reference old mode     state from before port removal switched the handlers to dummies. (CVE-2026-64190)

Note that Nessus relies on the presence of the package as reported by the vendor.

ID	Name	Product	Family	Type	Severity
343326	Unity Linux 20.1050e Security Update: kernel (UTSA-2026-073357)	Nessus	Unity Linux Local Security Checks	Local	medium
328339	Linux Distros Unpatched Vulnerability : CVE-2026-64190	Nessus	Misc.	Local	medium
322087	Amazon Linux 2023 : bpftool6.18, kernel6.18, kernel6.18-devel (ALAS2023-2026-1881)	Nessus	Amazon Linux Local Security Checks	Local	high

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CVE-2026-64190

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