[syzbot] [mm?] [xfs?] KASAN: slab-use-after-free Read in filemap_map_pages

syzbot
2025-01-01T04:06:29Z

Hello,

syzbot found the following issue on:

HEAD commit: 8155b4ef3466 Add linux-next specific files for 20241220
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=10633018580000
kernel config: https://syzkaller.appspot.com/x/.config?x=9c90bb7161a56c88
dashboard link: https://syzkaller.appspot.com/bug?extid=14d047423f40dc1dac89
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=14a1fadf980000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17ed90b0580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/98a974fc662d/disk-8155b4ef.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/2dea9b72f624/vmlinux-8155b4ef.xz
kernel image: https://storage.googleapis.com/syzbot-assets/593a42b9eb34/bzImage-8155b4ef.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/fc321fb08e1d/mount_0.gz

Bisection is inconclusive: the first bad commit could be any of:

568570fdf2b9 Merge tag 'xfs-6.12-fixes-4' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux
6aca91c416f6 cifs: Remove unused functions
b04ae0f45168 Merge tag 'v6.12-rc3-smb3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=13c5a818580000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+14d047423f40dc1dac89@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: slab-use-after-free in ptep_get include/linux/pgtable.h:338 [inline]
BUG: KASAN: slab-use-after-free in filemap_map_folio_range mm/filemap.c:3632 [inline]
BUG: KASAN: slab-use-after-free in filemap_map_pages+0xf14/0x1900 mm/filemap.c:3748
Read of size 8 at addr ffff88807c164000 by task syz-executor318/6008

CPU: 0 UID: 0 PID: 6008 Comm: syz-executor318 Not tainted 6.13.0-rc3-next-20241220-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0x169/0x550 mm/kasan/report.c:489
kasan_report+0x143/0x180 mm/kasan/report.c:602
ptep_get include/linux/pgtable.h:338 [inline]
filemap_map_folio_range mm/filemap.c:3632 [inline]
filemap_map_pages+0xf14/0x1900 mm/filemap.c:3748
do_fault_around mm/memory.c:5351 [inline]
do_read_fault mm/memory.c:5384 [inline]
do_fault mm/memory.c:5527 [inline]
do_pte_missing mm/memory.c:4048 [inline]
handle_pte_fault+0x3888/0x5ee0 mm/memory.c:5890
__handle_mm_fault mm/memory.c:6033 [inline]
handle_mm_fault+0x11f5/0x1d50 mm/memory.c:6202
faultin_page mm/gup.c:1196 [inline]
__get_user_pages+0x1a92/0x4140 mm/gup.c:1491
populate_vma_page_range+0x264/0x330 mm/gup.c:1929
__mm_populate+0x27a/0x460 mm/gup.c:2032
mm_populate include/linux/mm.h:3400 [inline]
vm_mmap_pgoff+0x303/0x430 mm/util.c:585
ksys_mmap_pgoff+0x4eb/0x720 mm/mmap.c:607
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbc532801b9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 1a 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fbc52a0e208 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007fbc533174b8 RCX: 00007fbc532801b9
RDX: 0000000000000002 RSI: 0000000000b36000 RDI: 0000000020000000
RBP: 00007fbc533174b0 R08: 0000000000000004 R09: 0000000000000000
R10: 0000000000028011 R11: 0000000000000246 R12: 00007fbc532dcf08
R13: 0030656c69662f2e R14: 00746e6572727563 R15: 632e79726f6d656d
</TASK>

Allocated by task 5770:
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
unpoison_slab_object mm/kasan/common.c:319 [inline]
__kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:345
kasan_slab_alloc include/linux/kasan.h:250 [inline]
slab_post_alloc_hook mm/slub.c:4115 [inline]
kmem_cache_alloc_bulk_noprof+0x4fa/0x7c0 mm/slub.c:5125
mt_alloc_bulk lib/maple_tree.c:181 [inline]
mas_alloc_nodes+0x38e/0x7e0 lib/maple_tree.c:1275
mas_node_count_gfp lib/maple_tree.c:1335 [inline]
mas_preallocate+0x575/0x8d0 lib/maple_tree.c:5505
vma_iter_prealloc mm/vma.h:353 [inline]
__split_vma+0x302/0xc50 mm/vma.c:480
split_vma mm/vma.c:543 [inline]
vma_modify+0x244/0x330 mm/vma.c:1530
vma_modify_flags+0x3a5/0x430 mm/vma.c:1548
mprotect_fixup+0x45a/0xaa0 mm/mprotect.c:666
do_mprotect_pkey+0x99e/0xde0 mm/mprotect.c:840
__do_sys_mprotect mm/mprotect.c:861 [inline]
__se_sys_mprotect mm/mprotect.c:858 [inline]
__x64_sys_mprotect+0x80/0x90 mm/mprotect.c:858
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 5770:
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:576
poison_slab_object mm/kasan/common.c:247 [inline]
__kasan_slab_free+0x59/0x70 mm/kasan/common.c:264
kasan_slab_free include/linux/kasan.h:233 [inline]
slab_free_hook mm/slub.c:2353 [inline]
slab_free mm/slub.c:4609 [inline]
kmem_cache_free+0x195/0x410 mm/slub.c:4711
mt_free_one lib/maple_tree.c:186 [inline]
mas_destroy+0x1955/0x1fe0 lib/maple_tree.c:5562
mas_store_prealloc+0xd23/0x1390 lib/maple_tree.c:5481
vma_complete+0x21d/0xb50 mm/vma.c:309
__split_vma+0xaa6/0xc50 mm/vma.c:513
split_vma mm/vma.c:543 [inline]
vma_modify+0x244/0x330 mm/vma.c:1530
vma_modify_flags+0x3a5/0x430 mm/vma.c:1548
mprotect_fixup+0x45a/0xaa0 mm/mprotect.c:666
do_mprotect_pkey+0x99e/0xde0 mm/mprotect.c:840
__do_sys_mprotect mm/mprotect.c:861 [inline]
__se_sys_mprotect mm/mprotect.c:858 [inline]
__x64_sys_mprotect+0x80/0x90 mm/mprotect.c:858
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88807c164000
which belongs to the cache maple_node of size 256
The buggy address is located 0 bytes inside of
freed 256-byte region [ffff88807c164000, ffff88807c164100)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7c164
head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88801ac91000 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801ac91000 dead000000000122 0000000000000000
head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 00fff00000000001 ffffea0001f05901 ffffffffffffffff 0000000000000000
head: 0000000000000002 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 1, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5770, tgid 5770 (sed), ts 64767761345, free_ts 64734581038
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x1f4/0x240 mm/page_alloc.c:1551
prep_new_page mm/page_alloc.c:1559 [inline]
get_page_from_freelist+0x365c/0x37a0 mm/page_alloc.c:3477
__alloc_frozen_pages_noprof+0x292/0x710 mm/page_alloc.c:4754
alloc_pages_mpol+0x30e/0x550 mm/mempolicy.c:2270
alloc_slab_page mm/slub.c:2423 [inline]
allocate_slab+0x8f/0x3a0 mm/slub.c:2587
new_slab mm/slub.c:2640 [inline]
___slab_alloc+0xc27/0x14a0 mm/slub.c:3826
__kmem_cache_alloc_bulk mm/slub.c:5045 [inline]
kmem_cache_alloc_bulk_noprof+0x21e/0x7c0 mm/slub.c:5117
mt_alloc_bulk lib/maple_tree.c:181 [inline]
mas_alloc_nodes+0x38e/0x7e0 lib/maple_tree.c:1275
mas_node_count_gfp lib/maple_tree.c:1335 [inline]
mas_preallocate+0x575/0x8d0 lib/maple_tree.c:5505
vma_iter_prealloc mm/vma.h:353 [inline]
__split_vma+0x302/0xc50 mm/vma.c:480
split_vma mm/vma.c:543 [inline]
vma_modify+0x244/0x330 mm/vma.c:1530
vma_modify_flags+0x3a5/0x430 mm/vma.c:1548
mprotect_fixup+0x45a/0xaa0 mm/mprotect.c:666
do_mprotect_pkey+0x99e/0xde0 mm/mprotect.c:840
__do_sys_mprotect mm/mprotect.c:861 [inline]
__se_sys_mprotect mm/mprotect.c:858 [inline]
__x64_sys_mprotect+0x80/0x90 mm/mprotect.c:858
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
page last free pid 0 tgid 0 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1127 [inline]
free_frozen_pages+0xe0d/0x10e0 mm/page_alloc.c:2660
__folio_put+0x2b3/0x360 mm/swap.c:112
__tlb_remove_table arch/x86/include/asm/tlb.h:34 [inline]
__tlb_remove_table_free mm/mmu_gather.c:227 [inline]
tlb_remove_table_rcu+0x76/0xf0 mm/mmu_gather.c:282
rcu_do_batch kernel/rcu/tree.c:2546 [inline]
rcu_core+0xaaa/0x17a0 kernel/rcu/tree.c:2802
handle_softirqs+0x2d4/0x9b0 kernel/softirq.c:561
__do_softirq kernel/softirq.c:595 [inline]
invoke_softirq kernel/softirq.c:435 [inline]
__irq_exit_rcu+0xf7/0x220 kernel/softirq.c:662
irq_exit_rcu+0x9/0x30 kernel/softirq.c:678
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1049
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702

Memory state around the buggy address:
ffff88807c163f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff88807c163f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88807c164000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88807c164080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88807c164100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================

---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
For information about bisection process see: https://goo.gl/tpsmEJ#bisection

If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup