[syzbot] [bluetooth?] KASAN: invalid-free in hci_req_sync_complete

syzbot
2024-04-22T06:47:29Z

Hello,

syzbot found the following issue on:

HEAD commit: dbe0a7be2838 Merge tag 'thermal-6.9-rc5' of git://git.kern..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1797a520980000
kernel config: https://syzkaller.appspot.com/x/.config?x=c5d33c579b4e833f
dashboard link: https://syzkaller.appspot.com/bug?extid=35ebc808442df6420eae
compiler: gcc (Debian 12.2.0-14) 12.2.0, 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/533abb2e04bb/disk-dbe0a7be.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/bab25bf1664b/vmlinux-dbe0a7be.xz
kernel image: https://storage.googleapis.com/syzbot-assets/a86e1d3d98aa/bzImage-dbe0a7be.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+35ebc808442df6420eae@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: double-free in kfree_skbmem+0x10e/0x200 net/core/skbuff.c:1159
Free of addr ffff8880114bcdc0 by task kworker/u9:0/52

CPU: 1 PID: 52 Comm: kworker/u9:0 Not tainted 6.9.0-rc4-syzkaller-00164-gdbe0a7be2838 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Workqueue: hci4 hci_rx_work
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_invalid_free+0xaa/0xd0 mm/kasan/report.c:563
poison_slab_object mm/kasan/common.c:232 [inline]
__kasan_slab_free+0x16b/0x1a0 mm/kasan/common.c:256
kasan_slab_free include/linux/kasan.h:184 [inline]
slab_free_hook mm/slub.c:2106 [inline]
slab_free mm/slub.c:4280 [inline]
kmem_cache_free+0x12e/0x380 mm/slub.c:4344
kfree_skbmem+0x10e/0x200 net/core/skbuff.c:1159
__kfree_skb net/core/skbuff.c:1217 [inline]
kfree_skb_reason+0x13a/0x210 net/core/skbuff.c:1252
kfree_skb include/linux/skbuff.h:1262 [inline]
hci_req_sync_complete+0x16c/0x270 net/bluetooth/hci_request.c:109
hci_event_packet+0x966/0x1170 net/bluetooth/hci_event.c:7604
hci_rx_work+0x2c4/0x1610 net/bluetooth/hci_core.c:4171
process_one_work+0x9ac/0x1ac0 kernel/workqueue.c:3254
process_scheduled_works kernel/workqueue.c:3335 [inline]
worker_thread+0x6c8/0xf70 kernel/workqueue.c:3416
kthread+0x2c4/0x3a0 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
</TASK>

Allocated by task 52:
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:3798 [inline]
slab_alloc_node mm/slub.c:3845 [inline]
kmem_cache_alloc+0x136/0x320 mm/slub.c:3852
skb_clone+0x190/0x3f0 net/core/skbuff.c:2063
hci_send_cmd_sync net/bluetooth/hci_core.c:4220 [inline]
hci_cmd_work+0x66a/0x710 net/bluetooth/hci_core.c:4240
process_one_work+0x9ac/0x1ac0 kernel/workqueue.c:3254
process_scheduled_works kernel/workqueue.c:3335 [inline]
worker_thread+0x6c8/0xf70 kernel/workqueue.c:3416
kthread+0x2c4/0x3a0 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Freed by task 10076:
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 mm/kasan/common.c:240 [inline]
__kasan_slab_free+0x11d/0x1a0 mm/kasan/common.c:256
kasan_slab_free include/linux/kasan.h:184 [inline]
slab_free_hook mm/slub.c:2106 [inline]
slab_free mm/slub.c:4280 [inline]
kmem_cache_free+0x12e/0x380 mm/slub.c:4344
kfree_skbmem+0x10e/0x200 net/core/skbuff.c:1159
__kfree_skb net/core/skbuff.c:1217 [inline]
kfree_skb_reason+0x13a/0x210 net/core/skbuff.c:1252
kfree_skb include/linux/skbuff.h:1262 [inline]
__hci_req_sync+0x61d/0x980 net/bluetooth/hci_request.c:184
hci_req_sync+0x97/0xd0 net/bluetooth/hci_request.c:206
hci_dev_cmd+0x653/0x9c0 net/bluetooth/hci_core.c:790
hci_sock_ioctl+0x4f3/0x8e0 net/bluetooth/hci_sock.c:1153
sock_do_ioctl+0x119/0x280 net/socket.c:1222
sock_ioctl+0x22e/0x6c0 net/socket.c:1341
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:904 [inline]
__se_sys_ioctl fs/ioctl.c:890 [inline]
__x64_sys_ioctl+0x196/0x220 fs/ioctl.c:890
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcf/0x260 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff8880114bcdc0
which belongs to the cache skbuff_head_cache of size 240
The buggy address is located 0 bytes inside of
240-byte region [ffff8880114bcdc0, ffff8880114bceb0)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x114bc
flags: 0xfff80000000800(slab|node=0|zone=1|lastcpupid=0xfff)
page_type: 0xffffffff()
raw: 00fff80000000800 ffff888018ad6780 ffffea000183fd00 dead000000000002
raw: 0000000000000000 00000000800c000c 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x112cc0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY), pid 4748, tgid 666454001 (dhcpcd), ts 4748, free_ts 597626032748
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x2d4/0x350 mm/page_alloc.c:1534
prep_new_page mm/page_alloc.c:1541 [inline]
get_page_from_freelist+0xa28/0x3780 mm/page_alloc.c:3317
__alloc_pages+0x22b/0x2460 mm/page_alloc.c:4575
__alloc_pages_node include/linux/gfp.h:238 [inline]
alloc_pages_node include/linux/gfp.h:261 [inline]
alloc_slab_page mm/slub.c:2175 [inline]
allocate_slab mm/slub.c:2338 [inline]
new_slab+0xcc/0x3a0 mm/slub.c:2391
___slab_alloc+0x66d/0x1790 mm/slub.c:3525
__slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3610
__slab_alloc_node mm/slub.c:3663 [inline]
slab_alloc_node mm/slub.c:3835 [inline]
kmem_cache_alloc_node+0x10a/0x340 mm/slub.c:3888
__alloc_skb+0x2b1/0x380 net/core/skbuff.c:658
alloc_skb include/linux/skbuff.h:1313 [inline]
alloc_skb_with_frags+0xe4/0x710 net/core/skbuff.c:6504
sock_alloc_send_pskb+0x7f1/0x980 net/core/sock.c:2795
unix_dgram_sendmsg+0x4b9/0x1b10 net/unix/af_unix.c:2019
sock_sendmsg_nosec net/socket.c:730 [inline]
__sock_sendmsg net/socket.c:745 [inline]
sock_write_iter+0x50d/0x5c0 net/socket.c:1160
call_write_iter include/linux/fs.h:2110 [inline]
do_iter_readv_writev+0x507/0x780 fs/read_write.c:741
vfs_writev+0x36f/0xdb0 fs/read_write.c:971
do_writev+0x287/0x370 fs/read_write.c:1018
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcf/0x260 arch/x86/entry/common.c:83
page last free pid 8963 tgid 8961 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1141 [inline]
free_unref_page_prepare+0x527/0xb10 mm/page_alloc.c:2347
free_unref_page+0x33/0x3c0 mm/page_alloc.c:2487
tlb_batch_list_free mm/mmu_gather.c:159 [inline]
tlb_finish_mmu+0x237/0x7b0 mm/mmu_gather.c:468
exit_mmap+0x3da/0xb90 mm/mmap.c:3280
__mmput+0x12a/0x4d0 kernel/fork.c:1346
mmput+0x62/0x70 kernel/fork.c:1368
exit_mm kernel/exit.c:569 [inline]
do_exit+0x999/0x2c10 kernel/exit.c:865
do_group_exit+0xd3/0x2a0 kernel/exit.c:1027
get_signal+0x2616/0x2710 kernel/signal.c:2911
arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:310
exit_to_user_mode_loop kernel/entry/common.c:111 [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+0x14a/0x2a0 kernel/entry/common.c:218
do_syscall_64+0xdc/0x260 arch/x86/entry/common.c:89
entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
ffff8880114bcc80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff8880114bcd00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 fc fc
>ffff8880114bcd80: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb
^
ffff8880114bce00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8880114bce80: fb fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc
==================================================================

---
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