Re: [syzbot] [nilfs?] [mm?] KASAN: slab-use-after-free Read in lru_add_fn

syzbot
2024-06-11T18:10:21Z

syzbot has found a reproducer for the following issue on:

HEAD commit: 83a7eefedc9b Linux 6.10-rc3
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=15eb4c7a980000
kernel config: https://syzkaller.appspot.com/x/.config?x=b8786f381e62940f
dashboard link: https://syzkaller.appspot.com/bug?extid=d79afb004be235636ee8
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1073d8ee980000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17c645e2980000

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7bc7510fe41f/non_bootable_disk-83a7eefe.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/c1eea9d0e321/vmlinux-83a7eefe.xz
kernel image: https://storage.googleapis.com/syzbot-assets/1a79e458e1e6/bzImage-83a7eefe.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/1f873a22e09f/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+d79afb004be235636ee8@syzkaller.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_unevictable include/linux/pagemap.h:259 [inline]
BUG: KASAN: slab-use-after-free in folio_evictable mm/internal.h:353 [inline]
BUG: KASAN: slab-use-after-free in lru_add_fn+0x192/0xd70 mm/swap.c:184
Read of size 8 at addr ffff888032180b10 by task syz-executor358/5362

CPU: 2 PID: 5362 Comm: syz-executor358 Not tainted 6.10.0-rc3-syzkaller #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114
print_address_description mm/kasan/report.c:377 [inline]
print_report+0xc3/0x620 mm/kasan/report.c:488
kasan_report+0xd9/0x110 mm/kasan/report.c:601
check_region_inline mm/kasan/generic.c:183 [inline]
kasan_check_range+0xef/0x1a0 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_unevictable include/linux/pagemap.h:259 [inline]
folio_evictable mm/internal.h:353 [inline]
lru_add_fn+0x192/0xd70 mm/swap.c:184
folio_batch_move_lru+0x243/0x400 mm/swap.c:220
folio_batch_add_and_move+0xe5/0x160 mm/swap.c:236
folio_add_lru+0x37d/0x7f0 mm/swap.c:522
shmem_alloc_and_add_folio+0x4ae/0x790 mm/shmem.c:1722
shmem_get_folio_gfp+0x687/0x13d0 mm/shmem.c:2055
shmem_get_folio mm/shmem.c:2160 [inline]
shmem_write_begin+0x15a/0x360 mm/shmem.c:2743
generic_perform_write+0x272/0x620 mm/filemap.c:4015
shmem_file_write_iter+0x114/0x140 mm/shmem.c:2919
new_sync_write fs/read_write.c:497 [inline]
vfs_write+0x6b6/0x1140 fs/read_write.c:590
ksys_write+0x12f/0x260 fs/read_write.c:643
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f882e62a330
Code: 40 00 48 c7 c2 b8 ff ff ff f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 80 3d 71 9d 07 00 00 74 17 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 58 c3 0f 1f 80 00 00 00 00 48 83 ec 28 48 89
RSP: 002b:00007fffd60928f8 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fffd6092910 RCX: 00007f882e62a330
RDX: 0000000000100000 RSI: 00007f8826000000 RDI: 0000000000000003
RBP: 00007f8826000000 R08: 0000000000000ab9 R09: 0000000000000ab5
R10: 00000000000007c2 R11: 0000000000000202 R12: 00007fffd6092aac
R13: 00007fffd6092950 R14: 0000000000000003 R15: 0000000000100000
</TASK>

Allocated by task 5360:
kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
kasan_save_track+0x14/0x30 mm/kasan/common.c:68
unpoison_slab_object mm/kasan/common.c:312 [inline]
__kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:338
kasan_slab_alloc include/linux/kasan.h:201 [inline]
slab_post_alloc_hook mm/slub.c:3941 [inline]
slab_alloc_node mm/slub.c:4001 [inline]
kmem_cache_alloc_lru_noprof+0x121/0x2f0 mm/slub.c:4020
nilfs_alloc_inode+0x26/0x150 fs/nilfs2/super.c:154
alloc_inode+0x5d/0x230 fs/inode.c:261
iget5_locked fs/inode.c:1235 [inline]
iget5_locked+0x1c9/0x2c0 fs/inode.c:1228
nilfs_iget_locked+0xa1/0xe0 fs/nilfs2/inode.c:606
nilfs_ifile_read+0x2f/0x1e0 fs/nilfs2/ifile.c:192
nilfs_attach_checkpoint+0x12d/0x1d0 fs/nilfs2/super.c:557
nilfs_fill_super fs/nilfs2/super.c:1067 [inline]
nilfs_get_tree+0x951/0x1000 fs/nilfs2/super.c:1211
vfs_get_tree+0x8f/0x380 fs/super.c:1780
do_new_mount fs/namespace.c:3352 [inline]
path_mount+0x14e6/0x1f20 fs/namespace.c:3679
do_mount fs/namespace.c:3692 [inline]
__do_sys_mount fs/namespace.c:3898 [inline]
__se_sys_mount fs/namespace.c:3875 [inline]
__x64_sys_mount+0x297/0x320 fs/namespace.c:3875
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 0:
kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
kasan_save_track+0x14/0x30 mm/kasan/common.c:68
kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:579
poison_slab_object+0xf7/0x160 mm/kasan/common.c:240
__kasan_slab_free+0x32/0x50 mm/kasan/common.c:256
kasan_slab_free include/linux/kasan.h:184 [inline]
slab_free_hook mm/slub.c:2196 [inline]
slab_free mm/slub.c:4437 [inline]
kmem_cache_free+0x12f/0x3a0 mm/slub.c:4512
i_callback+0x43/0x70 fs/inode.c:250
rcu_do_batch kernel/rcu/tree.c:2535 [inline]
rcu_core+0x828/0x16b0 kernel/rcu/tree.c:2809
handle_softirqs+0x216/0x8f0 kernel/softirq.c:554
__do_softirq kernel/softirq.c:588 [inline]
invoke_softirq kernel/softirq.c:428 [inline]
__irq_exit_rcu kernel/softirq.c:637 [inline]
irq_exit_rcu+0xbb/0x120 kernel/softirq.c:649
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline]
sysvec_apic_timer_interrupt+0x95/0xb0 arch/x86/kernel/apic/apic.c:1043
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702

Last potentially related work creation:
kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
__kasan_record_aux_stack+0xba/0xd0 mm/kasan/generic.c:541
__call_rcu_common.constprop.0+0x9a/0x790 kernel/rcu/tree.c:3072
destroy_inode+0x12c/0x1b0 fs/inode.c:316
iput_final fs/inode.c:1741 [inline]
iput.part.0+0x5a8/0x7f0 fs/inode.c:1767
iput+0x5c/0x80 fs/inode.c:1757
nilfs_put_root+0xae/0xe0 fs/nilfs2/the_nilfs.c:925
nilfs_segctor_destroy fs/nilfs2/segment.c:2788 [inline]
nilfs_detach_log_writer+0x5ef/0xaa0 fs/nilfs2/segment.c:2850
nilfs_put_super+0x43/0x1b0 fs/nilfs2/super.c:498
generic_shutdown_super+0x159/0x3d0 fs/super.c:642
kill_block_super+0x3b/0x90 fs/super.c:1676
deactivate_locked_super+0xbe/0x1a0 fs/super.c:473
deactivate_super+0xde/0x100 fs/super.c:506
cleanup_mnt+0x222/0x450 fs/namespace.c:1267
task_work_run+0x14e/0x250 kernel/task_work.c:180
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0x278/0x2a0 kernel/entry/common.c:218
do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89
entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff888032180668
which belongs to the cache nilfs2_inode_cache of size 1512
The buggy address is located 1192 bytes inside of
freed 1512-byte region [ffff888032180668, ffff888032180c50)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x32180
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: 0xffffefff(slab)
raw: 00fff00000000040 ffff888016ad9540 ffffea0000c84e00 0000000000000002
raw: 0000000000000000 0000000080130013 00000001ffffefff 0000000000000000
head: 00fff00000000040 ffff888016ad9540 ffffea0000c84e00 0000000000000002
head: 0000000000000000 0000000080130013 00000001ffffefff 0000000000000000
head: 00fff00000000003 ffffea0000c86001 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 Reclaimable, gfp_mask 0xd2050(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_RECLAIMABLE), pid 5215, tgid 5215 (syz-executor358), ts 206379124412, free_ts 0
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x2d1/0x350 mm/page_alloc.c:1468
prep_new_page mm/page_alloc.c:1476 [inline]
get_page_from_freelist+0x136a/0x2e50 mm/page_alloc.c:3420
__alloc_pages_noprof+0x22b/0x2460 mm/page_alloc.c:4678
__alloc_pages_node_noprof include/linux/gfp.h:269 [inline]
alloc_pages_node_noprof include/linux/gfp.h:296 [inline]
alloc_slab_page+0x56/0x110 mm/slub.c:2265
allocate_slab mm/slub.c:2428 [inline]
new_slab+0x84/0x260 mm/slub.c:2481
___slab_alloc+0xdac/0x1870 mm/slub.c:3667
__slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3757
__slab_alloc_node mm/slub.c:3810 [inline]
slab_alloc_node mm/slub.c:3989 [inline]
kmem_cache_alloc_lru_noprof+0x2a0/0x2f0 mm/slub.c:4020
nilfs_alloc_inode+0x26/0x150 fs/nilfs2/super.c:154
alloc_inode+0x5d/0x230 fs/inode.c:261
iget5_locked fs/inode.c:1235 [inline]
iget5_locked+0x1c9/0x2c0 fs/inode.c:1228
nilfs_attach_btree_node_cache+0x255/0x410 fs/nilfs2/inode.c:684
nilfs_btree_init+0x1d6/0x2d0 fs/nilfs2/btree.c:2431
nilfs_bmap_read+0x3fc/0x6a0 fs/nilfs2/bmap.c:539
nilfs_read_inode_common+0x7c6/0x9f0 fs/nilfs2/inode.c:476
__nilfs_read_inode fs/nilfs2/inode.c:501 [inline]
nilfs_iget+0x2ae/0x850 fs/nilfs2/inode.c:621
page_owner free stack trace missing

Memory state around the buggy address:
ffff888032180a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888032180a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888032180b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888032180b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888032180c00: fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc fc
==================================================================

---
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