REISERFS (device loop0): using ordered data mode
reiserfs: using flush barriers
REISERFS (device loop0): journal params: device loop0, size 512, journal first block 18, max trans len 256, max batch 225, max commit age 30, max trans age 30
REISERFS (device loop0): checking transaction log (loop0)
REISERFS (device loop0): Using tea hash to sort names
REISERFS (device loop0): using 3.5.x disk format
==================================================================
BUG: KASAN: use-after-free in set_de_name_and_namelen fs/reiserfs/namei.c:81 [inline]
BUG: KASAN: use-after-free in linear_search_in_dir_item fs/reiserfs/namei.c:262 [inline]
BUG: KASAN: use-after-free in reiserfs_find_entry+0xc6d/0x18e0 fs/reiserfs/namei.c:331
Read of size 1 at addr ffff88806b092f83 by task syz.0.17/4361
CPU: 0 PID: 4361 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Call Trace:
<TASK>
dump_stack_lvl+0x168/0x230 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
set_de_name_and_namelen fs/reiserfs/namei.c:81 [inline]
linear_search_in_dir_item fs/reiserfs/namei.c:262 [inline]
reiserfs_find_entry+0xc6d/0x18e0 fs/reiserfs/namei.c:331
reiserfs_lookup+0x1a7/0x420 fs/reiserfs/namei.c:368
__lookup_slow+0x27d/0x3d0 fs/namei.c:1671
lookup_one_len+0x18e/0x2c0 fs/namei.c:2726
reiserfs_lookup_privroot+0x85/0x1e0 fs/reiserfs/xattr.c:980
reiserfs_fill_super+0x1f65/0x23e0 fs/reiserfs/super.c:2178
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+0x2d6/0x3c0 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: 0033:0x7f377d52d76a
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd0532fdc8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ffd0532fe50 RCX: 00007f377d52d76a
RDX: 0000200000000000 RSI: 0000200000000040 RDI: 00007ffd0532fe10
RBP: 0000200000000000 R08: 00007ffd0532fe50 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000200000000040
R13: 00007ffd0532fe10 R14: 000000000000111d R15: 0000200000000300
</TASK>
The buggy address belongs to the page:
page:ffffea0001ac2480 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x6b092
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 ffffea0001ac24c8 ffffea0001ac2448 0000000000000000
raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 0, migratetype Movable, gfp_mask 0x1100dca(GFP_HIGHUSER_MOVABLE|__GFP_ZERO), pid 4189, ts 54511601131, free_ts 57624754230
prep_new_page mm/page_alloc.c:2426 [inline]
get_page_from_freelist+0x1b77/0x1c60 mm/page_alloc.c:4192
__alloc_pages+0x1e1/0x470 mm/page_alloc.c:5487
alloc_pages_vma+0x393/0x7c0 mm/mempolicy.c:2146
do_anonymous_page mm/memory.c:3838 [inline]
handle_pte_fault mm/memory.c:4648 [inline]
__handle_mm_fault mm/memory.c:4785 [inline]
handle_mm_fault+0x237f/0x43b0 mm/memory.c:4883
do_user_addr_fault+0x489/0xc80 arch/x86/mm/fault.c:1357
handle_page_fault arch/x86/mm/fault.c:1445 [inline]
exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1501
asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:606
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_list+0x122/0x7e0 mm/page_alloc.c:3433
release_pages+0x184b/0x1bb0 mm/swap.c:963
tlb_batch_pages_flush mm/mmu_gather.c:49 [inline]
tlb_flush_mmu_free mm/mmu_gather.c:240 [inline]
tlb_flush_mmu mm/mmu_gather.c:247 [inline]
tlb_finish_mmu+0x164/0x2e0 mm/mmu_gather.c:338
unmap_region+0x315/0x360 mm/mmap.c:2669
__do_munmap+0x9d3/0xdc0 mm/mmap.c:2899
__vm_munmap+0x137/0x230 mm/mmap.c:2952
__do_sys_munmap mm/mmap.c:2978 [inline]
__se_sys_munmap mm/mmap.c:2974 [inline]
__x64_sys_munmap+0x67/0x70 mm/mmap.c:2974
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
Memory state around the buggy address:
ffff88806b092e80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff88806b092f00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88806b092f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
^
ffff88806b093000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff88806b093080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================