{"id":"AZL-83684","summary":"CVE-2026-31596 affecting package kernel for versions less than 6.6.137.1-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nocfs2: handle invalid dinode in ocfs2_group_extend\n\n[BUG]\nkernel BUG at fs/ocfs2/resize.c:308!\nOops: invalid opcode: 0000 [#1] SMP KASAN NOPTI\nRIP: 0010:ocfs2_group_extend+0x10aa/0x1ae0 fs/ocfs2/resize.c:308\nCode: 8b8520ff ffff83f8 860f8580 030000e8 5cc3c1fe\nCall Trace:\n ...\n ocfs2_ioctl+0x175/0x6e0 fs/ocfs2/ioctl.c:869\n vfs_ioctl fs/ioctl.c:51 [inline]\n __do_sys_ioctl fs/ioctl.c:597 [inline]\n __se_sys_ioctl fs/ioctl.c:583 [inline]\n __x64_sys_ioctl+0x197/0x1e0 fs/ioctl.c:583\n x64_sys_call+0x1144/0x26a0 arch/x86/include/generated/asm/syscalls_64.h:17\n do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0x93/0xf80 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x76/0x7e\n ...\n\n[CAUSE]\nocfs2_group_extend() assumes that the global bitmap inode block\nreturned from ocfs2_inode_lock() has already been validated and\nBUG_ONs when the signature is not a dinode. That assumption is too\nstrong for crafted filesystems because the JBD2-managed buffer path\ncan bypass structural validation and return an invalid dinode to the\nresize ioctl.\n\n[FIX]\nValidate the dinode explicitly in ocfs2_group_extend(). If the global\nbitmap buffer does not contain a valid dinode, report filesystem\ncorruption with ocfs2_error() and fail the resize operation instead of\ncrashing the kernel.","modified":"2026-08-28T17:47:34.478359424Z","published":"2026-04-24T15:16:37Z","upstream":["CVE-2026-31596"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-31596"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.6.137.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-83684.json"}}],"schema_version":"1.9.0"}