syzbot


KASAN: use-after-free Read in ntfs_iget5 (3)

Status: upstream: reported on 2026/01/12 20:01
Reported-by: syzbot+068c6664d354756b7b39@syzkaller.appspotmail.com
First crash: 73d, last: 15d
Similar bugs (8)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 KASAN: use-after-free Read in ntfs_iget5 19 7 861d 1108d 0/3 auto-obsoleted due to no activity on 2024/02/25 08:58
linux-5.15 KASAN: use-after-free Read in ntfs_iget5 19 5 928d 1069d 0/3 auto-obsoleted due to no activity on 2023/12/20 11:31
linux-5.15 KASAN: slab-out-of-bounds Read in ntfs_iget5 19 31 218d 479d 0/3 auto-obsoleted due to no activity on 2025/11/29 13:33
linux-5.15 KASAN: use-after-free Read in ntfs_iget5 (2) 19 5 625d 724d 0/3 auto-obsoleted due to no activity on 2024/10/18 06:28
upstream KASAN: slab-out-of-bounds Read in ntfs_iget5 ntfs3 19 C done done 3633 800d 1435d 25/29 fixed on 2024/03/20 11:33
linux-6.1 KASAN: use-after-free Read in ntfs_iget5 (2) origin:upstream 19 C error 51 1d03h 728d 0/3 upstream: reported C repro on 2024/03/29 09:18
linux-6.6 KASAN: slab-use-after-free Read in ntfs_iget5 19 14 3d01h 220d 0/2 upstream: reported on 2025/08/19 13:23
upstream BUG: unable to handle kernel paging request in ntfs_iget5 ntfs3 8 1 683d 679d 0/29 auto-obsoleted due to no activity on 2024/08/10 16:42

Sample crash report:
ntfs3: loop4: Different NTFS' sector size (1024) and media sector size (512)
==================================================================
BUG: KASAN: use-after-free in ntfs_iget5+0x14a/0x3760 fs/ntfs3/inode.c:528
Read of size 8 at addr ffff88805f939340 by task syz.4.2559/10099

CPU: 0 PID: 10099 Comm: syz.4.2559 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 print_address_description+0x60/0x2d0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:434 [inline]
 kasan_report+0xdf/0x130 mm/kasan/report.c:451
 ntfs_iget5+0x14a/0x3760 fs/ntfs3/inode.c:528
 ntfs_fill_super+0x1db1/0x37b0 fs/ntfs3/super.c:1004
 get_tree_bdev+0x3f1/0x610 fs/super.c:1325
 vfs_get_tree+0x88/0x270 fs/super.c:1530
 do_new_mount+0x24a/0xa40 fs/namespace.c:3034
 do_mount fs/namespace.c:3377 [inline]
 __do_sys_mount fs/namespace.c:3585 [inline]
 __se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3562
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f59a8daaa0a
Code: 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f59a7002e58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f59a7002ee0 RCX: 00007f59a8daaa0a
RDX: 000020000001f800 RSI: 000020000001f840 RDI: 00007f59a7002ea0
RBP: 000020000001f800 R08: 00007f59a7002ee0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000020000001f840
R13: 00007f59a7002ea0 R14: 000000000001f7f9 R15: 000020000001f880
 </TASK>

Allocated by task 6985:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 __kasan_slab_alloc+0x9c/0xd0 mm/kasan/common.c:467
 kasan_slab_alloc include/linux/kasan.h:254 [inline]
 slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519
 slab_alloc_node mm/slub.c:3225 [inline]
 slab_alloc mm/slub.c:3233 [inline]
 kmem_cache_alloc+0x100/0x290 mm/slub.c:3238
 reiserfs_alloc_inode+0x19/0xb0 fs/reiserfs/super.c:642
 alloc_inode fs/inode.c:261 [inline]
 iget5_locked+0x9e/0x250 fs/inode.c:1263
 reiserfs_fill_super+0x122d/0x2440 fs/reiserfs/super.c:2057
 mount_bdev+0x287/0x3c0 fs/super.c:1400
 legacy_get_tree+0xe6/0x180 fs/fs_context.c:611
 vfs_get_tree+0x88/0x270 fs/super.c:1530
 do_new_mount+0x24a/0xa40 fs/namespace.c:3034
 do_mount fs/namespace.c:3377 [inline]
 __do_sys_mount fs/namespace.c:3585 [inline]
 __se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3562
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

Last potentially related work creation:
 kasan_save_stack+0x35/0x60 mm/kasan/common.c:38
 kasan_record_aux_stack+0xb8/0x100 mm/kasan/generic.c:348
 __call_rcu kernel/rcu/tree.c:3011 [inline]
 call_rcu+0x189/0x950 kernel/rcu/tree.c:3091
 destroy_inode fs/inode.c:316 [inline]
 evict+0x834/0x8d0 fs/inode.c:662
 reiserfs_fill_super+0x14c4/0x2440 fs/reiserfs/super.c:2082
 mount_bdev+0x287/0x3c0 fs/super.c:1400
 legacy_get_tree+0xe6/0x180 fs/fs_context.c:611
 vfs_get_tree+0x88/0x270 fs/super.c:1530
 do_new_mount+0x24a/0xa40 fs/namespace.c:3034
 do_mount fs/namespace.c:3377 [inline]
 __do_sys_mount fs/namespace.c:3585 [inline]
 __se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3562
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

Second to last potentially related work creation:
 kasan_save_stack+0x35/0x60 mm/kasan/common.c:38
 kasan_record_aux_stack+0xb8/0x100 mm/kasan/generic.c:348
 __call_rcu kernel/rcu/tree.c:3011 [inline]
 call_rcu+0x189/0x950 kernel/rcu/tree.c:3091
 destroy_inode fs/inode.c:316 [inline]
 evict+0x834/0x8d0 fs/inode.c:662
 __dentry_kill+0x431/0x650 fs/dcache.c:586
 dentry_kill+0xb8/0x290 fs/dcache.c:-1
 dput+0xd8/0x1a0 fs/dcache.c:893
 reiserfs_fill_super+0x150f/0x2440 fs/reiserfs/super.c:2093
 mount_bdev+0x287/0x3c0 fs/super.c:1400
 legacy_get_tree+0xe6/0x180 fs/fs_context.c:611
 vfs_get_tree+0x88/0x270 fs/super.c:1530
 do_new_mount+0x24a/0xa40 fs/namespace.c:3034
 do_mount fs/namespace.c:3377 [inline]
 __do_sys_mount fs/namespace.c:3585 [inline]
 __se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3562
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

The buggy address belongs to the object at ffff88805f938d40
 which belongs to the cache reiser_inode_cache of size 1568
The buggy address is located 1536 bytes inside of
 1568-byte region [ffff88805f938d40, ffff88805f939360)
The buggy address belongs to the page:
page:ffffea00017e4e00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88805f939a80 pfn:0x5f938
head:ffffea00017e4e00 order:3 compound_mapcount:0 compound_pincount:0
memcg:ffff88801ebf3001
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 0000000000000000 dead000000000122 ffff88801dfb9000
raw: ffff88805f939a80 000000008013000f 00000001ffffffff ffff88801ebf3001
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Reclaimable, gfp_mask 0x1d20d0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL|__GFP_RECLAIMABLE), pid 4283, ts 63115933437, free_ts 11568006886
 prep_new_page mm/page_alloc.c:2426 [inline]
 get_page_from_freelist+0x1bbd/0x1ca0 mm/page_alloc.c:4192
 __alloc_pages+0x1ee/0x480 mm/page_alloc.c:5501
 alloc_slab_page mm/slub.c:1780 [inline]
 allocate_slab mm/slub.c:1917 [inline]
 new_slab+0xc0/0x4b0 mm/slub.c:1980
 ___slab_alloc+0x80a/0xdd0 mm/slub.c:3013
 __slab_alloc mm/slub.c:3100 [inline]
 slab_alloc_node mm/slub.c:3191 [inline]
 slab_alloc mm/slub.c:3233 [inline]
 kmem_cache_alloc+0x195/0x290 mm/slub.c:3238
 reiserfs_alloc_inode+0x19/0xb0 fs/reiserfs/super.c:642
 alloc_inode fs/inode.c:261 [inline]
 iget5_locked+0x9e/0x250 fs/inode.c:1263
 reiserfs_fill_super+0x122d/0x2440 fs/reiserfs/super.c:2057
 mount_bdev+0x287/0x3c0 fs/super.c:1400
 legacy_get_tree+0xe6/0x180 fs/fs_context.c:611
 vfs_get_tree+0x88/0x270 fs/super.c:1530
 do_new_mount+0x24a/0xa40 fs/namespace.c:3034
 do_mount fs/namespace.c:3377 [inline]
 __do_sys_mount fs/namespace.c:3585 [inline]
 __se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3562
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1340 [inline]
 free_pcp_prepare mm/page_alloc.c:1391 [inline]
 free_unref_page_prepare+0x637/0x6c0 mm/page_alloc.c:3317
 free_unref_page+0x8f/0x2a0 mm/page_alloc.c:3396
 free_contig_range+0x96/0xf0 mm/page_alloc.c:9428
 destroy_args+0xf0/0xa00 mm/debug_vm_pgtable.c:1018
 debug_vm_pgtable+0x321/0x380 mm/debug_vm_pgtable.c:1336
 do_one_initcall+0x272/0x730 init/main.c:1316
 do_initcall_level+0x137/0x1f0 init/main.c:1389
 do_initcalls+0x4b/0x90 init/main.c:1405
 kernel_init_freeable+0x3e9/0x570 init/main.c:1629
 kernel_init+0x19/0x1b0 init/main.c:1520
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287

Memory state around the buggy address:
 ffff88805f939200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88805f939280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88805f939300: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
                                           ^
 ffff88805f939380: fc fc fc fc fc fc fc fc fc fc fc fc 00 00 00 00
 ffff88805f939400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/03/11 17:06 linux-5.15.y 91d48252ad4b 2d88ab01 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in ntfs_iget5
2026/03/04 11:33 linux-5.15.y 3330a8d33e08 e6b6b96b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in ntfs_iget5
2026/01/19 09:10 linux-5.15.y 68efe5a6c16a a9fc5226 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in ntfs_iget5
2026/01/12 20:00 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in ntfs_iget5
* Struck through repros no longer work on HEAD.