{"id":"AZL-64695","summary":"CVE-2025-38215 affecting package kernel for versions less than 6.6.96.1-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nfbdev: Fix do_register_framebuffer to prevent null-ptr-deref in fb_videomode_to_var\n\nIf fb_add_videomode() in do_register_framebuffer() fails to allocate\nmemory for fb_videomode, it will later lead to a null-ptr dereference in\nfb_videomode_to_var(), as the fb_info is registered while not having the\nmode in modelist that is expected to be there, i.e. the one that is\ndescribed in fb_info-\u003evar.\n\n================================================================\ngeneral protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN NOPTI\nKASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]\nCPU: 1 PID: 30371 Comm: syz-executor.1 Not tainted 5.10.226-syzkaller #0\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014\nRIP: 0010:fb_videomode_to_var+0x24/0x610 drivers/video/fbdev/core/modedb.c:901\nCall Trace:\n display_to_var+0x3a/0x7c0 drivers/video/fbdev/core/fbcon.c:929\n fbcon_resize+0x3e2/0x8f0 drivers/video/fbdev/core/fbcon.c:2071\n resize_screen drivers/tty/vt/vt.c:1176 [inline]\n vc_do_resize+0x53a/0x1170 drivers/tty/vt/vt.c:1263\n fbcon_modechanged+0x3ac/0x6e0 drivers/video/fbdev/core/fbcon.c:2720\n fbcon_update_vcs+0x43/0x60 drivers/video/fbdev/core/fbcon.c:2776\n do_fb_ioctl+0x6d2/0x740 drivers/video/fbdev/core/fbmem.c:1128\n fb_ioctl+0xe7/0x150 drivers/video/fbdev/core/fbmem.c:1203\n vfs_ioctl fs/ioctl.c:48 [inline]\n __do_sys_ioctl fs/ioctl.c:753 [inline]\n __se_sys_ioctl fs/ioctl.c:739 [inline]\n __x64_sys_ioctl+0x19a/0x210 fs/ioctl.c:739\n do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46\n entry_SYSCALL_64_after_hwframe+0x67/0xd1\n================================================================\n\nEven though fbcon_init() checks beforehand if fb_match_mode() in\nvar_to_display() fails, it can not prevent the panic because fbcon_init()\ndoes not return error code. Considering this and the comment in the code\nabout fb_match_mode() returning NULL - \"This should not happen\" - it is\nbetter to prevent registering the fb_info if its mode was not set\nsuccessfully. Also move fb_add_videomode() closer to the beginning of\ndo_register_framebuffer() to avoid having to do the cleanup on fail.\n\nFound by Linux Verification Center (linuxtesting.org) with Syzkaller.","modified":"2026-04-01T05:20:23.449172Z","published":"2025-07-04T14:15:29Z","upstream":["CVE-2025-38215"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-38215"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.6.96.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-64695.json"}}],"schema_version":"1.7.5"}