bisecting fixing commit since cbfa1702aaf69b2311ea1b35e04f113c48368c67 building syzkaller on 1b88c6d5c8477f1d4fb3b389443b200acc32e9a8 testing commit cbfa1702aaf69b2311ea1b35e04f113c48368c67 with gcc (GCC) 8.4.1 20210217 kernel signature: 4b83bad0512e6984adb81d79ff42a6bcbacf5a14a5eb18f26b2d1569063be3fa run #0: crashed: KASAN: use-after-free Read in ntfs_are_names_equal run #1: crashed: KASAN: use-after-free Read in ntfs_are_names_equal run #2: crashed: KASAN: use-after-free Read in ntfs_are_names_equal run #3: crashed: KASAN: use-after-free Read in ntfs_are_names_equal run #4: crashed: KASAN: use-after-free Read in ntfs_are_names_equal run #5: crashed: KASAN: use-after-free Read in ntfs_are_names_equal run #6: crashed: KASAN: use-after-free Read in ntfs_are_names_equal run #7: crashed: KASAN: use-after-free Read in ntfs_are_names_equal run #8: crashed: KASAN: use-after-free Read in ntfs_are_names_equal run #9: crashed: KASAN: use-after-free Read in ntfs_are_names_equal run #10: crashed: KASAN: use-after-free Read in ntfs_are_names_equal run #11: crashed: KASAN: use-after-free Read in ntfs_are_names_equal run #12: crashed: KASAN: out-of-bounds Read in ntfs_are_names_equal run #13: crashed: KASAN: use-after-free Read in ntfs_are_names_equal run #14: crashed: KASAN: use-after-free Read in ntfs_are_names_equal run #15: crashed: KASAN: use-after-free Read in ntfs_are_names_equal run #16: crashed: KASAN: use-after-free Read in ntfs_are_names_equal run #17: crashed: KASAN: use-after-free Read in ntfs_are_names_equal run #18: crashed: KASAN: use-after-free Read in ntfs_are_names_equal run #19: crashed: KASAN: use-after-free Read in ntfs_are_names_equal testing current HEAD 3242aa3a635c0958671ee1e4b0958dcc7c4e5c79 testing commit 3242aa3a635c0958671ee1e4b0958dcc7c4e5c79 with gcc (GCC) 8.4.1 20210217 kernel signature: ed3673e4deab891e212bc530b7b94f5094aa50ed2082160eae10d053194db4f2 all runs: crashed: KASAN: use-after-free Read in ntfs_are_names_equal revisions tested: 2, total time: 21m42.948002455s (build: 14m32.689314565s, test: 6m15.851477449s) the crash still happens on HEAD commit msg: Linux 4.14.222 crash: KASAN: use-after-free Read in ntfs_are_names_equal batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! ================================================================== batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3d) already exists on: batadv_slave_0 BUG: KASAN: use-after-free in ntfs_ucsncmp fs/ntfs/unistr.c:156 [inline] BUG: KASAN: use-after-free in ntfs_are_names_equal+0x178/0x1a0 fs/ntfs/unistr.c:75 Read of size 2 at addr ffff8881ca23cee8 by task syz-executor.3/7224 batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! CPU: 0 PID: 7224 Comm: syz-executor.3 Not tainted 4.14.222-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x14b/0x1e7 lib/dump_stack.c:58 print_address_description.cold.6+0x9/0x1ca mm/kasan/report.c:252 batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3d) already exists on: batadv_slave_0 kasan_report_error mm/kasan/report.c:351 [inline] kasan_report mm/kasan/report.c:409 [inline] kasan_report.cold.7+0x11a/0x2d3 mm/kasan/report.c:393 __asan_report_load2_noabort+0x14/0x20 mm/kasan/report.c:428 ntfs_ucsncmp fs/ntfs/unistr.c:156 [inline] ntfs_are_names_equal+0x178/0x1a0 fs/ntfs/unistr.c:75 ntfs_attr_find+0x36c/0xb60 fs/ntfs/attrib.c:628 ntfs_external_attr_find fs/ntfs/attrib.c:1107 [inline] ntfs_attr_lookup+0x1085/0x2470 fs/ntfs/attrib.c:1205 batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! ntfs_read_locked_attr_inode fs/ntfs/inode.c:1266 [inline] ntfs_attr_iget+0x742/0x23c0 fs/ntfs/inode.c:251 ntfs_read_locked_inode+0x25c1/0x51f0 fs/ntfs/inode.c:986 ntfs_iget+0xda/0x110 fs/ntfs/inode.c:190 load_system_files fs/ntfs/super.c:1988 [inline] ntfs_fill_super+0x4c0c/0x76c0 fs/ntfs/super.c:2908 batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3d) already exists on: batadv_slave_0 mount_bdev+0x26f/0x330 fs/super.c:1134 ntfs_mount+0x10/0x20 fs/ntfs/super.c:3065 mount_fs+0x7f/0x270 fs/super.c:1237 vfs_kern_mount.part.9+0x58/0x3c0 fs/namespace.c:1046 vfs_kern_mount fs/namespace.c:1036 [inline] do_new_mount fs/namespace.c:2549 [inline] do_mount+0x352/0x2af0 fs/namespace.c:2879 batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! SYSC_mount fs/namespace.c:3095 [inline] SyS_mount+0xb1/0xd0 fs/namespace.c:3072 do_syscall_64+0x1c7/0x5b0 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x466baa batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3d) already exists on: batadv_slave_0 RSP: 002b:00007f5aa803ffa8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000020000200 RCX: 0000000000466baa RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007f5aa8040000 RBP: 00007f5aa8040040 R08: 00007f5aa8040040 R09: 0000000020000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000020000000 R13: 0000000020000100 R14: 00007f5aa8040000 R15: 000000002007dc00 The buggy address belongs to the page: page:ffffea0007288f00 count:0 mapcount:0 mapping: (null) index:0x1 flags: 0x17ffe0000000000() raw: 017ffe0000000000 0000000000000000 0000000000000001 00000000ffffffff raw: ffffea0007288f60 ffffea0007283060 0000000000000000 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8881ca23cd80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8881ca23ce00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff8881ca23ce80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff8881ca23cf00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8881ca23cf80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ==================================================================