{"id":"AZL-62824","summary":"CVE-2025-21976 affecting package kernel 6.6.126.1-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nfbdev: hyperv_fb: Allow graceful removal of framebuffer\n\nWhen a Hyper-V framebuffer device is unbind, hyperv_fb driver tries to\nrelease the framebuffer forcefully. If this framebuffer is in use it\nproduce the following WARN and hence this framebuffer is never released.\n\n[   44.111220] WARNING: CPU: 35 PID: 1882 at drivers/video/fbdev/core/fb_info.c:70 framebuffer_release+0x2c/0x40\n\u003c snip \u003e\n[   44.111289] Call Trace:\n[   44.111290]  \u003cTASK\u003e\n[   44.111291]  ? show_regs+0x6c/0x80\n[   44.111295]  ? __warn+0x8d/0x150\n[   44.111298]  ? framebuffer_release+0x2c/0x40\n[   44.111300]  ? report_bug+0x182/0x1b0\n[   44.111303]  ? handle_bug+0x6e/0xb0\n[   44.111306]  ? exc_invalid_op+0x18/0x80\n[   44.111308]  ? asm_exc_invalid_op+0x1b/0x20\n[   44.111311]  ? framebuffer_release+0x2c/0x40\n[   44.111313]  ? hvfb_remove+0x86/0xa0 [hyperv_fb]\n[   44.111315]  vmbus_remove+0x24/0x40 [hv_vmbus]\n[   44.111323]  device_remove+0x40/0x80\n[   44.111325]  device_release_driver_internal+0x20b/0x270\n[   44.111327]  ? bus_find_device+0xb3/0xf0\n\nFix this by moving the release of framebuffer and assosiated memory\nto fb_ops.fb_destroy function, so that framebuffer framework handles\nit gracefully.\n\nWhile we fix this, also replace manual registrations/unregistration of\nframebuffer with devm_register_framebuffer.","modified":"2026-04-01T05:20:11.266924Z","published":"2025-04-01T16:15:28Z","upstream":["CVE-2025-21976"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-21976"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"6.6.126.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-62824.json"}}],"schema_version":"1.7.5"}