{"id":"CVE-2026-72341","summary":"net/mlx5e: Fix publication race for priv-\u003echannel_stats[]","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/mlx5e: Fix publication race for priv-\u003echannel_stats[]\n\nmlx5e_channel_stats_alloc() publishes a new entry to\npriv-\u003echannel_stats[] and then increments priv-\u003estats_nch as a\npublication token, but neither store carries any memory barrier:\n\n\tpriv-\u003echannel_stats[ix] = kvzalloc_node(...);\n\tif (!priv-\u003echannel_stats[ix])\n\t\treturn -ENOMEM;\n\tpriv-\u003estats_nch++;\n\nConcurrent readers compute the loop bound from priv-\u003estats_nch and\nthen dereference priv-\u003echannel_stats[i] using plain accesses, e.g.\n\n\tfor (i = 0; i \u003c priv-\u003estats_nch; i++) {\n\t\tstruct mlx5e_channel_stats *cs = priv-\u003echannel_stats[i];\n\t\t... cs-\u003erq.packets ...\n\t}\n\nOn weakly-ordered architectures (ARM, PowerPC, RISC-V) the writes to\nchannel_stats[ix] and stats_nch may become visible to other CPUs out\nof program order. A reader can observe stats_nch == N while still\nseeing channel_stats[N-1] == NULL, leading to a NULL pointer\ndereference in the channel_stats loop.\n\nThis has been observed in production on BlueField-3 DPUs (arm64),\nwhere ovs-vswitchd queries netdev statistics over netlink during NIC\nbringup, racing mlx5e_open_channel() -\u003e mlx5e_channel_stats_alloc()\non another CPU:\n\n  Unable to handle kernel NULL pointer dereference at virtual address 0x840\n  Hardware name: BlueField-3 DPU\n  pc : mlx5e_fold_sw_stats64+0x30/0x180 [mlx5_core]\n  Call trace:\n   mlx5e_fold_sw_stats64+0x30/0x180 [mlx5_core]\n   dev_get_stats+0x50/0xc0\n   ovs_vport_get_stats+0x38/0xac [openvswitch]\n   ovs_vport_cmd_fill_info+0x194/0x290 [openvswitch]\n   ovs_vport_cmd_get+0xbc/0x10c [openvswitch]\n   genl_family_rcv_msg_doit+0xd0/0x160\n   genl_rcv_msg+0xec/0x1f0\n   netlink_rcv_skb+0x64/0x130\n   genl_rcv+0x40/0x60\n   netlink_unicast+0x2fc/0x370\n   netlink_sendmsg+0x1dc/0x454\n   ...\n   __arm64_sys_sendmsg+0x2c/0x40\n\nAdd mlx5e_stats_nch_write() and mlx5e_stats_nch_read() helpers in en.h\nthat wrap the smp_store_release()/smp_load_acquire() pair on stats_nch.\nThe release/acquire pair establishes the contract:\n\n  stats_nch == N  =\u003e  channel_stats[0..N-1] are visible and non-NULL.\n\nPublish the stats_nch increment via mlx5e_stats_nch_write() in the\nwriter (mlx5e_channel_stats_alloc()), and read stats_nch via\nmlx5e_stats_nch_read() in all readers: mlx5e RX/TX queue stats,\nmlx5e_get_base_stats(), ethtool channels stats, IPoIB stats, the\nsw_stats fold and the HV VHCA stats agent.","modified":"2026-08-16T03:48:37.294721324Z","published":"2026-08-15T05:55:47.764Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/72xxx/CVE-2026-72341.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/5a799714e8ca0bce9ea40694f49914cf1adbbaa9"},{"type":"WEB","url":"https://git.kernel.org/stable/c/5c7e3755abf663f033de24f917b77685e9543045"},{"type":"WEB","url":"https://git.kernel.org/stable/c/815515ec68f527ca755cb1e2c1ff9148f6b3ea56"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/72xxx/CVE-2026-72341.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-72341"},{"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":"fa691d0c9c0812b9045f3a9420862e47b3b92518"},{"fixed":"5c7e3755abf663f033de24f917b77685e9543045"},{"fixed":"815515ec68f527ca755cb1e2c1ff9148f6b3ea56"},{"fixed":"5a799714e8ca0bce9ea40694f49914cf1adbbaa9"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-72341.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.17.0"},{"fixed":"6.18.40"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.1.5"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-72341.json"}}],"schema_version":"1.9.0"}