Message-ID: <6722cd86.050a0220.35b515.00d2.GAE@google.com>
Date: Wed, 30 Oct 2024 17:21:26 -0700
From: syzbot <syzbot+0133df8780a76867f88a@...kaller.appspotmail.com>
To: akpm@...ux-foundation.org, linux-kernel@...r.kernel.org, 
	linux-mm@...ck.org, syzkaller-bugs@...glegroups.com
Subject: [syzbot] [mm?] KASAN: slab-use-after-free Read in move_to_new_folio (3)

Hello,

syzbot found the following issue on:

HEAD commit:    c2ee9f594da8 KVM: selftests: Fix build on on non-x86 archi..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=10f0c640580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=fc6f8ce8c5369043
dashboard link: https://syzkaller.appspot.com/bug?extid=0133df8780a76867f88a
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/c35ff46634e3/disk-c2ee9f59.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/afb5a0aa9f0c/vmlinux-c2ee9f59.xz
kernel image: https://storage.googleapis.com/syzbot-assets/83d5809de2f4/bzImage-c2ee9f59.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+0133df8780a76867f88a@...kaller.appspotmail.com

==================================================================
BUG: KASAN: slab-use-after-free in instrument_atomic_read include/linux/instrumented.h:68 [inline]
BUG: KASAN: slab-use-after-free in _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
BUG: KASAN: slab-use-after-free in mapping_inaccessible include/linux/pagemap.h:335 [inline]
BUG: KASAN: slab-use-after-free in move_to_new_folio+0x231/0x1330 mm/migrate.c:1048
Read of size 8 at addr ffff888024d50b50 by task syz.1.4981/29836

CPU: 1 UID: 0 PID: 29836 Comm: syz.1.4981 Not tainted 6.12.0-rc4-syzkaller-00047-gc2ee9f594da8 #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:377 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:488
 kasan_report+0x143/0x180 mm/kasan/report.c:601
 kasan_check_range+0x282/0x290 mm/kasan/generic.c:189
 instrument_atomic_read include/linux/instrumented.h:68 [inline]
 _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
 mapping_inaccessible include/linux/pagemap.h:335 [inline]
 move_to_new_folio+0x231/0x1330 mm/migrate.c:1048
 migrate_folio_move mm/migrate.c:1366 [inline]
 migrate_pages_batch+0x266b/0x36d0 mm/migrate.c:1897
 migrate_pages_sync mm/migrate.c:1963 [inline]
 migrate_pages+0x2062/0x3560 mm/migrate.c:2072
 compact_zone+0x3404/0x4af0 mm/compaction.c:2641
 compact_node mm/compaction.c:2910 [inline]
 compact_nodes mm/compaction.c:2932 [inline]
 sysctl_compaction_handler+0x496/0x990 mm/compaction.c:2983
 proc_sys_call_handler+0x550/0x8b0 fs/proc/proc_sysctl.c:595
 iter_file_splice_write+0xbfa/0x1510 fs/splice.c:743
 do_splice_from fs/splice.c:941 [inline]
 direct_splice_actor+0x11b/0x220 fs/splice.c:1164
 splice_direct_to_actor+0x586/0xc80 fs/splice.c:1108
 do_splice_direct_actor fs/splice.c:1207 [inline]
 do_splice_direct+0x289/0x3e0 fs/splice.c:1233
 do_sendfile+0x561/0xe10 fs/read_write.c:1388
 __do_sys_sendfile64 fs/read_write.c:1449 [inline]
 __se_sys_sendfile64+0x100/0x1e0 fs/read_write.c:1441
 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: 0033:0x7fae28b7dff9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fae29993038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007fae28d35f80 RCX: 00007fae28b7dff9
RDX: 00000000200000c0 RSI: 0000000000000004 RDI: 0000000000000006
RBP: 00007fae28bf0296 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000005 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fae28d35f80 R15: 00007fae28e5fa28
 </TASK>

Allocated by task 27:
 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:247 [inline]
 slab_post_alloc_hook mm/slub.c:4085 [inline]
 slab_alloc_node mm/slub.c:4134 [inline]
 kmem_cache_alloc_lru_noprof+0x139/0x2b0 mm/slub.c:4153
 shmem_alloc_inode+0x28/0x40 mm/shmem.c:4764
 alloc_inode+0x65/0x1a0 fs/inode.c:265
 new_inode_pseudo fs/inode.c:1104 [inline]
 new_inode+0x22/0x1d0 fs/inode.c:1123
 __shmem_get_inode mm/shmem.c:2801 [inline]
 shmem_get_inode+0x34a/0xd70 mm/shmem.c:2872
 shmem_mknod+0x5f/0x1e0 mm/shmem.c:3568
 vfs_mknod+0x36d/0x3b0 fs/namei.c:4135
 handle_create drivers/base/devtmpfs.c:219 [inline]
 handle drivers/base/devtmpfs.c:384 [inline]
 devtmpfs_work_loop+0x963/0x1040 drivers/base/devtmpfs.c:399
 devtmpfsd+0x4c/0x50 drivers/base/devtmpfs.c:441
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Freed by task 28128:
 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:579
 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:230 [inline]
 slab_free_hook mm/slub.c:2342 [inline]
 slab_free mm/slub.c:4579 [inline]
 kmem_cache_free+0x1a2/0x420 mm/slub.c:4681
 rcu_do_batch kernel/rcu/tree.c:2567 [inline]
 rcu_core+0xaaa/0x17a0 kernel/rcu/tree.c:2823
 handle_softirqs+0x2c5/0x980 kernel/softirq.c:554
 __do_softirq kernel/softirq.c:588 [inline]
 invoke_softirq kernel/softirq.c:428 [inline]
 __irq_exit_rcu+0xf4/0x1c0 kernel/softirq.c:637
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:649
 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

Last potentially related work creation:
 kasan_save_stack+0x3f/0x60 mm/kasan/common.c:47
 __kasan_record_aux_stack+0xac/0xc0 mm/kasan/generic.c:541
 __call_rcu_common kernel/rcu/tree.c:3086 [inline]
 call_rcu+0x167/0xa70 kernel/rcu/tree.c:3190
 destroy_inode fs/inode.c:320 [inline]
 evict+0x83c/0x9b0 fs/inode.c:756
 do_unlinkat+0x512/0x830 fs/namei.c:4540
 __do_sys_unlink fs/namei.c:4581 [inline]
 __se_sys_unlink fs/namei.c:4579 [inline]
 __x64_sys_unlink+0x47/0x50 fs/namei.c:4579
 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 ffff888024d50688
 which belongs to the cache shmem_inode_cache of size 1544
The buggy address is located 1224 bytes inside of
 freed 1544-byte region [ffff888024d50688, ffff888024d50c90)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x24d50
head: order:3 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 ffff88801c6e5140 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000130013 00000001f5000000 0000000000000000
head: 00fff00000000040 ffff88801c6e5140 dead000000000122 0000000000000000
head: 0000000000000000 0000000000130013 00000001f5000000 0000000000000000
head: 00fff00000000003 ffffea0000935401 ffffffffffffffff 0000000000000000
head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 27, tgid 27 (kdevtmpfs), ts 8771129661, free_ts 0
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1537
 prep_new_page mm/page_alloc.c:1545 [inline]
 get_page_from_freelist+0x3045/0x3190 mm/page_alloc.c:3457
 __alloc_pages_noprof+0x292/0x710 mm/page_alloc.c:4733
 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265
 alloc_slab_page+0x6a/0x120 mm/slub.c:2412
 allocate_slab+0x5a/0x2f0 mm/slub.c:2578
 new_slab mm/slub.c:2631 [inline]
 ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3818
 __slab_alloc+0x58/0xa0 mm/slub.c:3908
 __slab_alloc_node mm/slub.c:3961 [inline]
 slab_alloc_node mm/slub.c:4122 [inline]
 kmem_cache_alloc_lru_noprof+0x1c5/0x2b0 mm/slub.c:4153
 shmem_alloc_inode+0x28/0x40 mm/shmem.c:4764
 alloc_inode+0x65/0x1a0 fs/inode.c:265
 new_inode_pseudo fs/inode.c:1104 [inline]
 new_inode+0x22/0x1d0 fs/inode.c:1123
 __shmem_get_inode mm/shmem.c:2801 [inline]
 shmem_get_inode+0x34a/0xd70 mm/shmem.c:2872
 shmem_mknod+0x5f/0x1e0 mm/shmem.c:3568
 vfs_mknod+0x36d/0x3b0 fs/namei.c:4135
 handle_create drivers/base/devtmpfs.c:219 [inline]
 handle drivers/base/devtmpfs.c:384 [inline]
 devtmpfs_work_loop+0x963/0x1040 drivers/base/devtmpfs.c:399
page_owner free stack trace missing

Memory state around the buggy address:
 ffff888024d50a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888024d50a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888024d50b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                 ^
 ffff888024d50b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888024d50c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


---
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