{"id":"AZL-103625","summary":"CVE-2026-97439 affecting package kernel 6.6.157.1-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nfs/ntfs3: preserve non-DOS attribute bits in system.dos_attrib\n\n[BUG]\nA corrupted ntfs3 image can hit a NULL function pointer call in\ngeneric_perform_write() after toggling system.ntfs_attrib and then\noverwriting system.dos_attrib on the same file.\n\nBUG: kernel NULL pointer dereference, address: 0000000000000000\n\\#PF: supervisor instruction fetch in kernel mode\n\\#PF: error_code(0x0010) - not-present page\nPGD bed5067 P4D bed5067 PUD 0\nOops: Oops: 0010 [#1] SMP KASAN NOPTI\nRIP: 0010:0x0\nCode: Unable to access opcode bytes at 0xffffffffffffffd6.\nRSP: 0018:ffff88801025f988 EFLAGS: 00010246\nCall Trace:\n generic_perform_write+0x409/0x8c0 mm/filemap.c:4255\n __generic_file_write_iter+0x1bb/0x200 mm/filemap.c:4372\n ntfs_file_write_iter+0xcd9/0x1c20 fs/ntfs3/file.c:1253\n new_sync_write fs/read_write.c:593 [inline]\n vfs_write+0x63b/0xf70 fs/read_write.c:686\n ksys_write+0x133/0x250 fs/read_write.c:738\n __do_sys_write fs/read_write.c:749 [inline]\n __se_sys_write fs/read_write.c:746 [inline]\n __x64_sys_write+0x77/0xc0 fs/read_write.c:746\n ...\n\n[CAUSE]\nsystem.ntfs_attrib updates ATTR_DATA flags via ni_new_attr_flags()\nand switches i_mapping-\u003ea_ops to ntfs_aops_cmpr when\nFILE_ATTRIBUTE_COMPRESSED is set. system.dos_attrib then overwrites\nni-\u003estd_fa from a one-byte DOS attribute value, clearing the compression\nbit without updating ATTR_DATA or the mapping operations.\n\nOld buffered writes use is_compressed(ni) to choose\n__generic_file_write_iter(). That leaves generic_perform_write() calling\na NULL write_begin callback from ntfs_aops_cmpr.\n\n[FIX]\nTreat system.dos_attrib as a low-byte DOS attribute update and preserve the\nexisting non-DOS attribute bits in ni-\u003estd_fa. This keeps compressed and\nsparse state consistent with ATTR_DATA and the mapping operations while\nkeeping the existing DOS attribute semantics intact.","modified":"2026-09-25T14:16:23.939985755Z","published":"2026-09-24T17:17:22Z","upstream":["CVE-2026-97439"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-97439"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"6.6.157.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-103625.json"}}],"schema_version":"1.9.0"}