Re: [syzbot] [fs?] KASAN: slab-use-after-free Read in lockref_get

From: syzbot
Date: Wed Jul 17 2024 - 07:18:11 EST


Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KASAN: slab-use-after-free Read in lockref_get

wlan1: send auth to 08:02:11:00:00:00 (try 2/3)
wlan1: send auth to 08:02:11:00:00:00 (try 3/3)
wlan1: authentication with 08:02:11:00:00:00 timed out
==================================================================
BUG: KASAN: slab-use-after-free in __lock_acquire+0x78/0x1fd0 kernel/locking/lockdep.c:5005
Read of size 8 at addr ffff88806706cf60 by task kworker/u8:3/51

CPU: 1 PID: 51 Comm: kworker/u8:3 Not tainted 6.10.0-rc6-syzkaller-01414-g58f9416d413a-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
Workqueue: events_unbound cfg80211_wiphy_work
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
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
__lock_acquire+0x78/0x1fd0 kernel/locking/lockdep.c:5005
lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:351 [inline]
lockref_get+0x15/0x60 lib/lockref.c:50
dget include/linux/dcache.h:333 [inline]
simple_recursive_removal+0x35/0x8e0 fs/libfs.c:601
debugfs_remove+0x49/0x70 fs/debugfs/inode.c:823
ieee80211_sta_debugfs_remove+0x98/0xe0 net/mac80211/debugfs_sta.c:1291
__sta_info_destroy_part2+0x35e/0x450 net/mac80211/sta_info.c:1476
__sta_info_destroy net/mac80211/sta_info.c:1492 [inline]
sta_info_destroy_addr+0xf4/0x140 net/mac80211/sta_info.c:1504
ieee80211_destroy_auth_data+0x139/0x270 net/mac80211/mlme.c:4163
ieee80211_sta_work+0x1256/0x3850 net/mac80211/mlme.c:7801
cfg80211_wiphy_work+0x2db/0x490 net/wireless/core.c:440
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:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
</TASK>

Allocated by task 786:
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:312 [inline]
__kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:338
kasan_slab_alloc include/linux/kasan.h:201 [inline]
slab_post_alloc_hook mm/slub.c:3940 [inline]
slab_alloc_node mm/slub.c:4002 [inline]
kmem_cache_alloc_lru_noprof+0x139/0x2b0 mm/slub.c:4021
__d_alloc+0x31/0x700 fs/dcache.c:1624
d_alloc fs/dcache.c:1704 [inline]
d_alloc_parallel+0xdf/0x1600 fs/dcache.c:2462
__lookup_slow+0x117/0x3f0 fs/namei.c:1677
lookup_one_len+0x18b/0x2d0 fs/namei.c:2764
start_creating+0x187/0x310 fs/debugfs/inode.c:378
debugfs_create_dir+0x25/0x430 fs/debugfs/inode.c:593
ieee80211_sta_debugfs_add+0x132/0x820 net/mac80211/debugfs_sta.c:1262
sta_info_insert_finish net/mac80211/sta_info.c:881 [inline]
sta_info_insert_rcu+0xecf/0x1900 net/mac80211/sta_info.c:949
sta_info_insert+0x16/0xc0 net/mac80211/sta_info.c:954
ieee80211_prep_connection+0xecd/0x12d0 net/mac80211/mlme.c:8319
ieee80211_mgd_auth+0xd42/0x14c0 net/mac80211/mlme.c:8564
rdev_auth net/wireless/rdev-ops.h:485 [inline]
cfg80211_mlme_auth+0x59f/0x980 net/wireless/mlme.c:291
cfg80211_conn_do_work+0x5ed/0xe60 net/wireless/sme.c:181
cfg80211_conn_work+0x27c/0x4d0 net/wireless/sme.c:271
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:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Freed by task 16:
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:4438 [inline]
kmem_cache_free+0x145/0x350 mm/slub.c:4513
rcu_do_batch kernel/rcu/tree.c:2535 [inline]
rcu_core+0xafd/0x1830 kernel/rcu/tree.c:2809
handle_softirqs+0x2c4/0x970 kernel/softirq.c:554
run_ksoftirqd+0xca/0x130 kernel/softirq.c:928
smpboot_thread_fn+0x544/0xa30 kernel/smpboot.c:164
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

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:3072 [inline]
call_rcu+0x167/0xa70 kernel/rcu/tree.c:3176
__dentry_kill+0x497/0x630 fs/dcache.c:622
dput+0x19f/0x2b0 fs/dcache.c:845
find_next_child fs/libfs.c:594 [inline]
simple_recursive_removal+0x2bd/0x8e0 fs/libfs.c:609
debugfs_remove+0x49/0x70 fs/debugfs/inode.c:823
ieee80211_debugfs_remove_netdev net/mac80211/debugfs_netdev.c:1023 [inline]
ieee80211_debugfs_recreate_netdev+0xd5/0x1400 net/mac80211/debugfs_netdev.c:1047
drv_remove_interface+0x1e1/0x590 net/mac80211/driver-ops.c:119
_ieee80211_change_mac net/mac80211/iface.c:278 [inline]
ieee80211_change_mac+0xaf5/0x11e0 net/mac80211/iface.c:310
dev_set_mac_address+0x327/0x510 net/core/dev.c:9095
dev_set_mac_address_user+0x31/0x50 net/core/dev.c:9114
dev_ifsioc+0xbd9/0xe70 net/core/dev_ioctl.c:541
dev_ioctl+0x719/0x1340 net/core/dev_ioctl.c:786
sock_do_ioctl+0x240/0x460 net/socket.c:1236
sock_ioctl+0x629/0x8e0 net/socket.c:1341
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:907 [inline]
__se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893
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 ffff88806706ceb0
which belongs to the cache dentry of size 312
The buggy address is located 176 bytes inside of
freed 312-byte region [ffff88806706ceb0, ffff88806706cfe8)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x6706c
head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff88802d138201
ksm flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffefff(slab)
raw: 00fff00000000040 ffff888015ef98c0 ffffea00019c0d80 dead000000000003
raw: 0000000000000000 0000000000150015 00000001ffffefff ffff88802d138201
head: 00fff00000000040 ffff888015ef98c0 ffffea00019c0d80 dead000000000003
head: 0000000000000000 0000000000150015 00000001ffffefff ffff88802d138201
head: 00fff00000000001 ffffea00019c1b01 ffffffffffffffff 0000000000000000
head: 0000000700000002 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 1, migratetype Reclaimable, gfp_mask 0x1d20d0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL|__GFP_RECLAIMABLE), pid 4548, tgid 4548 (udevd), ts 79059185868, free_ts 66719430476
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1473
prep_new_page mm/page_alloc.c:1481 [inline]
get_page_from_freelist+0x2e4c/0x2f10 mm/page_alloc.c:3425
__alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4683
__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:3990 [inline]
kmem_cache_alloc_lru_noprof+0x1c5/0x2b0 mm/slub.c:4021
__d_alloc+0x31/0x700 fs/dcache.c:1624
d_alloc fs/dcache.c:1704 [inline]
d_alloc_parallel+0xdf/0x1600 fs/dcache.c:2462
__lookup_slow+0x117/0x3f0 fs/namei.c:1677
lookup_slow+0x53/0x70 fs/namei.c:1709
walk_component+0x2e1/0x410 fs/namei.c:2004
lookup_last fs/namei.c:2469 [inline]
path_lookupat+0x16f/0x450 fs/namei.c:2493
filename_lookup+0x256/0x610 fs/namei.c:2522
user_path_at_empty+0x42/0x60 fs/namei.c:2929
page last free pid 5092 tgid 5092 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1093 [inline]
free_unref_folios+0xf23/0x19e0 mm/page_alloc.c:2637
folios_put_refs+0x93a/0xa60 mm/swap.c:1024
free_pages_and_swap_cache+0x2ea/0x690 mm/swap_state.c:329
__tlb_batch_free_encoded_pages mm/mmu_gather.c:136 [inline]
tlb_batch_pages_flush mm/mmu_gather.c:149 [inline]
tlb_flush_mmu_free mm/mmu_gather.c:366 [inline]
tlb_flush_mmu+0x3a3/0x680 mm/mmu_gather.c:373
tlb_finish_mmu+0xd4/0x200 mm/mmu_gather.c:465
unmap_region+0x2df/0x350 mm/mmap.c:2370
do_vmi_align_munmap+0x1122/0x18c0 mm/mmap.c:2683
do_vmi_munmap+0x261/0x2f0 mm/mmap.c:2759
__vm_munmap+0x1fc/0x400 mm/mmap.c:3038
__do_sys_munmap mm/mmap.c:3055 [inline]
__se_sys_munmap mm/mmap.c:3052 [inline]
__x64_sys_munmap+0x68/0x80 mm/mmap.c:3052
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:
ffff88806706ce00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc
ffff88806706ce80: fc fc fc fc fc fc fa fb fb fb fb fb fb fb fb fb
>ffff88806706cf00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88806706cf80: fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc
ffff88806706d000: fc fc fc fc fc fa fb fb fb fb fb fb fb fb fb fb
==================================================================


Tested on:

commit: 58f9416d Merge branch 'ice-support-to-dump-phy-config-..
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git
console output: https://syzkaller.appspot.com/x/log.txt?x=12e6a03d980000
kernel config: https://syzkaller.appspot.com/x/.config?x=db697e01efa9d1d7
dashboard link: https://syzkaller.appspot.com/bug?extid=d5dc2801166df6d34774
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
patch: https://syzkaller.appspot.com/x/patch.diff?x=13a3b731980000