{"id":"CVE-2026-97439","summary":"fs/ntfs3: preserve non-DOS attribute bits in system.dos_attrib","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":"2026-10-22T10:32:47.417928352Z","published":"2026-09-24T16:03:52.427Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/97xxx/CVE-2026-97439.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/2de91ae285b0b878604d2bd83c3c395a8071e482"},{"type":"WEB","url":"https://git.kernel.org/stable/c/407ee19828a7d9700969ed9cc53be50d0f533619"},{"type":"WEB","url":"https://git.kernel.org/stable/c/533217b90addd57cc16f1c974e023c72d18949c7"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b1c1101067d9536bcb0fe023b96ee2dde5535959"},{"type":"WEB","url":"https://git.kernel.org/stable/c/f2d6bc89e2236939df189831707c8cdad199f57a"},{"type":"WEB","url":"https://git.kernel.org/stable/c/fdc9f65aa6631df04238c6154713bacd5133d77c"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/97xxx/CVE-2026-97439.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-97439"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"be71b5cba2e6485e8959da7a9f9a44461a1bb074"},{"fixed":"533217b90addd57cc16f1c974e023c72d18949c7"},{"fixed":"f2d6bc89e2236939df189831707c8cdad199f57a"},{"fixed":"fdc9f65aa6631df04238c6154713bacd5133d77c"},{"fixed":"2de91ae285b0b878604d2bd83c3c395a8071e482"},{"fixed":"407ee19828a7d9700969ed9cc53be50d0f533619"},{"fixed":"b1c1101067d9536bcb0fe023b96ee2dde5535959"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-97439.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.15.0"},{"fixed":"5.15.222"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.189"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.158"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.111"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.53"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-97439.json"}}],"schema_version":"1.9.2"}