{"id":"AZL-56390","summary":"CVE-2025-21675 affecting package kernel for versions less than 6.6.76.1-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/mlx5: Clear port select structure when fail to create\n\nClear the port select structure on error so no stale values left after\ndefiners are destroyed. That's because the mlx5_lag_destroy_definers()\nalways try to destroy all lag definers in the tt_map, so in the flow\nbelow lag definers get double-destroyed and cause kernel crash:\n\n  mlx5_lag_port_sel_create()\n    mlx5_lag_create_definers()\n      mlx5_lag_create_definer()     \u003c- Failed on tt 1\n        mlx5_lag_destroy_definers() \u003c- definers[tt=0] gets destroyed\n  mlx5_lag_port_sel_create()\n    mlx5_lag_create_definers()\n      mlx5_lag_create_definer()     \u003c- Failed on tt 0\n        mlx5_lag_destroy_definers() \u003c- definers[tt=0] gets double-destroyed\n\n Unable to handle kernel NULL pointer dereference at virtual address 0000000000000008\n Mem abort info:\n   ESR = 0x0000000096000005\n   EC = 0x25: DABT (current EL), IL = 32 bits\n   SET = 0, FnV = 0\n   EA = 0, S1PTW = 0\n   FSC = 0x05: level 1 translation fault\n Data abort info:\n   ISV = 0, ISS = 0x00000005, ISS2 = 0x00000000\n   CM = 0, WnR = 0, TnD = 0, TagAccess = 0\n   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0\n user pgtable: 64k pages, 48-bit VAs, pgdp=0000000112ce2e00\n [0000000000000008] pgd=0000000000000000, p4d=0000000000000000, pud=0000000000000000\n Internal error: Oops: 0000000096000005 [#1] PREEMPT SMP\n Modules linked in: iptable_raw bonding ip_gre ip6_gre gre ip6_tunnel tunnel6 geneve ip6_udp_tunnel udp_tunnel ipip tunnel4 ip_tunnel rdma_ucm(OE) rdma_cm(OE) iw_cm(OE) ib_ipoib(OE) ib_cm(OE) ib_umad(OE) mlx5_ib(OE) ib_uverbs(OE) mlx5_fwctl(OE) fwctl(OE) mlx5_core(OE) mlxdevm(OE) ib_core(OE) mlxfw(OE) memtrack(OE) mlx_compat(OE) openvswitch nsh nf_conncount psample xt_conntrack xt_MASQUERADE nf_conntrack_netlink nfnetlink xfrm_user xfrm_algo xt_addrtype iptable_filter iptable_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 br_netfilter bridge stp llc netconsole overlay efi_pstore sch_fq_codel zram ip_tables crct10dif_ce qemu_fw_cfg fuse ipv6 crc_ccitt [last unloaded: mlx_compat(OE)]\n  CPU: 3 UID: 0 PID: 217 Comm: kworker/u53:2 Tainted: G           OE      6.11.0+ #2\n  Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE\n  Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015\n  Workqueue: mlx5_lag mlx5_do_bond_work [mlx5_core]\n  pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)\n  pc : mlx5_del_flow_rules+0x24/0x2c0 [mlx5_core]\n  lr : mlx5_lag_destroy_definer+0x54/0x100 [mlx5_core]\n  sp : ffff800085fafb00\n  x29: ffff800085fafb00 x28: ffff0000da0c8000 x27: 0000000000000000\n  x26: ffff0000da0c8000 x25: ffff0000da0c8000 x24: ffff0000da0c8000\n  x23: ffff0000c31f81a0 x22: 0400000000000000 x21: ffff0000da0c8000\n  x20: 0000000000000000 x19: 0000000000000001 x18: 0000000000000000\n  x17: 0000000000000000 x16: 0000000000000000 x15: 0000ffff8b0c9350\n  x14: 0000000000000000 x13: ffff800081390d18 x12: ffff800081dc3cc0\n  x11: 0000000000000001 x10: 0000000000000b10 x9 : ffff80007ab7304c\n  x8 : ffff0000d00711f0 x7 : 0000000000000004 x6 : 0000000000000190\n  x5 : ffff00027edb3010 x4 : 0000000000000000 x3 : 0000000000000000\n  x2 : ffff0000d39b8000 x1 : ffff0000d39b8000 x0 : 0400000000000000\n  Call trace:\n   mlx5_del_flow_rules+0x24/0x2c0 [mlx5_core]\n   mlx5_lag_destroy_definer+0x54/0x100 [mlx5_core]\n   mlx5_lag_destroy_definers+0xa0/0x108 [mlx5_core]\n   mlx5_lag_port_sel_create+0x2d4/0x6f8 [mlx5_core]\n   mlx5_activate_lag+0x60c/0x6f8 [mlx5_core]\n   mlx5_do_bond_work+0x284/0x5c8 [mlx5_core]\n   process_one_work+0x170/0x3e0\n   worker_thread+0x2d8/0x3e0\n   kthread+0x11c/0x128\n   ret_from_fork+0x10/0x20\n  Code: a9025bf5 aa0003f6 a90363f7 f90023f9 (f9400400)\n  ---[ end trace 0000000000000000 ]---","modified":"2026-04-01T05:18:52.902001Z","published":"2025-01-31T12:15:28Z","upstream":["CVE-2025-21675"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-21675"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.6.76.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-56390.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"}]}