[moderation] [bcachefs?] KASAN: slab-use-after-free Read in bch2_fs_recovery

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: ee78a17615ad Add linux-next specific files for 20240606
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=16084036980000
kernel config: https://syzkaller.appspot.com/x/.config?x=a8c69ee180de0793
dashboard link: https://syzkaller.appspot.com/bug?extid=35acd834391beabda27d
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
CC: [bfo...@redhat.com kent.ov...@linux.dev linux-b...@vger.kernel.org linux-...@vger.kernel.org]

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/c685971c3d74/disk-ee78a176.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/e36ba73a22c7/vmlinux-ee78a176.xz
kernel image: https://storage.googleapis.com/syzbot-assets/39ed510b9963/bzImage-ee78a176.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+35acd8...@syzkaller.appspotmail.com

bcachefs (loop0): recovering from clean shutdown, journal seq 10
bcachefs (loop0): Doing compatible version upgrade from 1.7: mi_btree_bitmap to 1.9: disk_accounting_v2
running recovery passes: check_allocations
==================================================================
BUG: KASAN: slab-use-after-free in bch2_fs_recovery+0xe85/0x38c0 fs/bcachefs/recovery.c:699
Read of size 8 at addr ffff88807f038f98 by task syz-executor.0/11883

CPU: 0 PID: 11883 Comm: syz-executor.0 Tainted: G W 6.10.0-rc2-next-20240606-syzkaller #0
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:91 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:117
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
bch2_fs_recovery+0xe85/0x38c0 fs/bcachefs/recovery.c:699
bch2_fs_start+0x356/0x5b0 fs/bcachefs/super.c:1029
bch2_fs_get_tree+0xce4/0x1620 fs/bcachefs/fs.c:1922
vfs_get_tree+0x90/0x2a0 fs/super.c:1780
do_new_mount+0x2be/0xb40 fs/namespace.c:3352
do_mount fs/namespace.c:3692 [inline]
__do_sys_mount fs/namespace.c:3898 [inline]
__se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3875
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: 0033:0x7fe7ea87e66a
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 09 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fe7eb59aef8 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fe7eb59af80 RCX: 00007fe7ea87e66a
RDX: 0000000020011a00 RSI: 0000000020011a40 RDI: 00007fe7eb59af40
RBP: 0000000020011a00 R08: 00007fe7eb59af80 R09: 0000000001008054
R10: 0000000001008054 R11: 0000000000000202 R12: 0000000020011a40
R13: 00007fe7eb59af40 R14: 00000000000119f5 R15: 0000000020000100
</TASK>

Allocated by task 11883:
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
poison_kmalloc_redzone mm/kasan/common.c:370 [inline]
__kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:387
kasan_kmalloc include/linux/kasan.h:211 [inline]
__do_kmalloc_node mm/slub.c:4122 [inline]
kmalloc_node_track_caller_noprof+0x225/0x440 mm/slub.c:4142
__do_krealloc mm/slab_common.c:1183 [inline]
krealloc_noprof+0x7d/0x120 mm/slab_common.c:1216
bch2_sb_realloc+0x2f5/0x660 fs/bcachefs/super-io.c:189
__copy_super+0x5dc/0xe70 fs/bcachefs/super-io.c:579
bch2_sb_to_fs+0xab/0x150 fs/bcachefs/super-io.c:606
bch2_fs_alloc+0xd36/0x2040 fs/bcachefs/super.c:823
bch2_fs_open+0x8cc/0xdf0 fs/bcachefs/super.c:2104
bch2_fs_get_tree+0x750/0x1620 fs/bcachefs/fs.c:1909
vfs_get_tree+0x90/0x2a0 fs/super.c:1780
do_new_mount+0x2be/0xb40 fs/namespace.c:3352
do_mount fs/namespace.c:3692 [inline]
__do_sys_mount fs/namespace.c:3898 [inline]
__se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3875
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 11883:
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+0xe0/0x150 mm/kasan/common.c:240
__kasan_slab_free+0x37/0x60 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]
kfree+0x149/0x360 mm/slub.c:4558
krealloc_noprof+0xcf/0x120
bch2_sb_realloc+0x2f5/0x660 fs/bcachefs/super-io.c:189
bch2_sb_field_resize_id+0x140/0x7c0 fs/bcachefs/super-io.c:221
bch2_sb_counters_from_cpu+0xac/0x300 fs/bcachefs/sb-counters.c:67
bch2_write_super+0xe80/0x3c80 fs/bcachefs/super-io.c:966
bch2_fs_recovery+0xe6c/0x38c0 fs/bcachefs/recovery.c:697
bch2_fs_start+0x356/0x5b0 fs/bcachefs/super.c:1029
bch2_fs_get_tree+0xce4/0x1620 fs/bcachefs/fs.c:1922
vfs_get_tree+0x90/0x2a0 fs/super.c:1780
do_new_mount+0x2be/0xb40 fs/namespace.c:3352
do_mount fs/namespace.c:3692 [inline]
__do_sys_mount fs/namespace.c:3898 [inline]
__se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3875
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 ffff88807f038000
which belongs to the cache kmalloc-4k of size 4096
The buggy address is located 3992 bytes inside of
freed 4096-byte region [ffff88807f038000, ffff88807f039000)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7f038
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: 0xfdffffff(slab)
raw: 00fff00000000040 ffff888015042140 dead000000000100 dead000000000122
raw: 0000000000000000 0000000000040004 00000001fdffffff 0000000000000000
head: 00fff00000000040 ffff888015042140 dead000000000100 dead000000000122
head: 0000000000000000 0000000000040004 00000001fdffffff 0000000000000000
head: 00fff00000000003 ffffea0001fc0e01 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 0x1d2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 5163, tgid 5163 (kworker/1:5), ts 302972278904, free_ts 302906664519
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1470
prep_new_page mm/page_alloc.c:1478 [inline]
get_page_from_freelist+0x2cbd/0x2d70 mm/page_alloc.c:3457
__alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4715
__alloc_pages_node_noprof include/linux/gfp.h:269 [inline]
alloc_pages_node_noprof include/linux/gfp.h:296 [inline]
alloc_slab_page+0x5f/0x120 mm/slub.c:2265
allocate_slab+0x5a/0x2f0 mm/slub.c:2428
new_slab mm/slub.c:2481 [inline]
___slab_alloc+0xcd1/0x14b0 mm/slub.c:3667
__slab_alloc+0x58/0xa0 mm/slub.c:3757
__slab_alloc_node mm/slub.c:3810 [inline]
slab_alloc_node mm/slub.c:3989 [inline]
__do_kmalloc_node mm/slub.c:4121 [inline]
kmalloc_node_track_caller_noprof+0x281/0x440 mm/slub.c:4142
kmalloc_reserve+0x111/0x2a0 net/core/skbuff.c:597
__alloc_skb+0x1f3/0x440 net/core/skbuff.c:666
alloc_skb include/linux/skbuff.h:1314 [inline]
nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:748 [inline]
nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline]
nsim_dev_trap_report_work+0x254/0xaa0 drivers/net/netdevsim/dev.c:850
process_one_work kernel/workqueue.c:3248 [inline]
process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3329
worker_thread+0x86d/0xd50 kernel/workqueue.c:3409
kthread+0x2f0/0x390 kernel/kthread.c:389
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:145
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
page last free pid 5112 tgid 5112 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1089 [inline]
free_unref_page+0xd22/0xea0 mm/page_alloc.c:2621
discard_slab mm/slub.c:2527 [inline]
__put_partials+0xeb/0x130 mm/slub.c:2995
put_cpu_partial+0x17c/0x250 mm/slub.c:3070
__slab_free+0x2ea/0x3d0 mm/slub.c:4307
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x9e/0x140 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:322
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_noprof+0x135/0x2a0 mm/slub.c:4008
getname_flags+0xb7/0x540 fs/namei.c:139
getname fs/namei.c:225 [inline]
__do_sys_unlink fs/namei.c:4466 [inline]
__se_sys_unlink fs/namei.c:4464 [inline]
__x64_sys_unlink+0x3a/0x50 fs/namei.c:4464
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

Memory state around the buggy address:
ffff88807f038e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88807f038f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88807f038f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88807f039000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff88807f039080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================


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