{"id":"AZL-48231","summary":"CVE-2024-43900 affecting package kernel 5.15.200.1-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nmedia: xc2028: avoid use-after-free in load_firmware_cb()\n\nsyzkaller reported use-after-free in load_firmware_cb() [1].\nThe reason is because the module allocated a struct tuner in tuner_probe(),\nand then the module initialization failed, the struct tuner was released.\nA worker which created during module initialization accesses this struct\ntuner later, it caused use-after-free.\n\nThe process is as follows:\n\ntask-6504           worker_thread\ntuner_probe                             \u003c= alloc dvb_frontend [2]\n...\nrequest_firmware_nowait                 \u003c= create a worker\n...\ntuner_remove                            \u003c= free dvb_frontend\n...\n                    request_firmware_work_func  \u003c= the firmware is ready\n                    load_firmware_cb    \u003c= but now the dvb_frontend has been freed\n\nTo fix the issue, check the dvd_frontend in load_firmware_cb(), if it is\nnull, report a warning and just return.\n\n[1]:\n    ==================================================================\n     BUG: KASAN: use-after-free in load_firmware_cb+0x1310/0x17a0\n     Read of size 8 at addr ffff8000d7ca2308 by task kworker/2:3/6504\n\n     Call trace:\n      load_firmware_cb+0x1310/0x17a0\n      request_firmware_work_func+0x128/0x220\n      process_one_work+0x770/0x1824\n      worker_thread+0x488/0xea0\n      kthread+0x300/0x430\n      ret_from_fork+0x10/0x20\n\n     Allocated by task 6504:\n      kzalloc\n      tuner_probe+0xb0/0x1430\n      i2c_device_probe+0x92c/0xaf0\n      really_probe+0x678/0xcd0\n      driver_probe_device+0x280/0x370\n      __device_attach_driver+0x220/0x330\n      bus_for_each_drv+0x134/0x1c0\n      __device_attach+0x1f4/0x410\n      device_initial_probe+0x20/0x30\n      bus_probe_device+0x184/0x200\n      device_add+0x924/0x12c0\n      device_register+0x24/0x30\n      i2c_new_device+0x4e0/0xc44\n      v4l2_i2c_new_subdev_board+0xbc/0x290\n      v4l2_i2c_new_subdev+0xc8/0x104\n      em28xx_v4l2_init+0x1dd0/0x3770\n\n     Freed by task 6504:\n      kfree+0x238/0x4e4\n      tuner_remove+0x144/0x1c0\n      i2c_device_remove+0xc8/0x290\n      __device_release_driver+0x314/0x5fc\n      device_release_driver+0x30/0x44\n      bus_remove_device+0x244/0x490\n      device_del+0x350/0x900\n      device_unregister+0x28/0xd0\n      i2c_unregister_device+0x174/0x1d0\n      v4l2_device_unregister+0x224/0x380\n      em28xx_v4l2_init+0x1d90/0x3770\n\n     The buggy address belongs to the object at ffff8000d7ca2000\n      which belongs to the cache kmalloc-2k of size 2048\n     The buggy address is located 776 bytes inside of\n      2048-byte region [ffff8000d7ca2000, ffff8000d7ca2800)\n     The buggy address belongs to the page:\n     page:ffff7fe00035f280 count:1 mapcount:0 mapping:ffff8000c001f000 index:0x0\n     flags: 0x7ff800000000100(slab)\n     raw: 07ff800000000100 ffff7fe00049d880 0000000300000003 ffff8000c001f000\n     raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000\n     page dumped because: kasan: bad access detected\n\n     Memory state around the buggy address:\n      ffff8000d7ca2200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb\n      ffff8000d7ca2280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb\n     \u003effff8000d7ca2300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb\n                           ^\n      ffff8000d7ca2380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb\n      ffff8000d7ca2400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb\n     ==================================================================\n\n[2]\n    Actually, it is allocated for struct tuner, and dvb_frontend is inside.","modified":"2026-04-01T05:16:00.900878Z","published":"2024-08-26T11:15:04Z","upstream":["CVE-2024-43900"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2024-43900"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:2","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"5.15.200.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-48231.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:H/I:H/A:H"}]}