{"id":"AZL-64770","summary":"CVE-2025-38214 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 fb_set_var to prevent null-ptr-deref in fb_videomode_to_var\n\nIf fb_add_videomode() in fb_set_var() fails to allocate memory for\nfb_videomode, later it may 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\nThe reason is that fb_info-\u003evar is being modified in fb_set_var(), and\nthen fb_videomode_to_var() is called. If it fails to add the mode to\nfb_info-\u003emodelist, fb_set_var() returns error, but does not restore the\nold value of fb_info-\u003evar. Restore fb_info-\u003evar on failure the same way\nit is done earlier in the function.\n\nFound by Linux Verification Center (linuxtesting.org) with Syzkaller.","modified":"2026-04-01T05:20:23.883445Z","published":"2025-07-04T14:15:29Z","upstream":["CVE-2025-38214"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-38214"}],"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-64770.json"}}],"schema_version":"1.7.5"}