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

syzbot
2024-06-19T11:23:25Z

syzbot has found a reproducer for the following issue on:

HEAD commit: 2ccbdf43d5e7 Merge tag 'for-linus' of git://git.kernel.org..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=10d61bca980000
kernel config: https://syzkaller.appspot.com/x/.config?x=b8786f381e62940f
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
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=125874ea980000

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7bc7510fe41f/non_bootable_disk-2ccbdf43.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/c40c1cd990d2/vmlinux-2ccbdf43.xz
kernel image: https://storage.googleapis.com/syzbot-assets/a2a94050804e/bzImage-2ccbdf43.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:1131
Free of addr ffff888025dce280 by task kworker/u33:6/5317

CPU: 2 PID: 5317 Comm: kworker/u33:6 Not tainted 6.10.0-rc3-syzkaller-00044-g2ccbdf43d5e7 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Workqueue: hci0 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+0x135/0x160 mm/kasan/common.c:232
__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
kfree_skbmem+0x10e/0x200 net/core/skbuff.c:1131
__kfree_skb net/core/skbuff.c:1188 [inline]
kfree_skb_reason+0x138/0x210 net/core/skbuff.c:1223
kfree_skb include/linux/skbuff.h:1257 [inline]
hci_req_sync_complete+0x16c/0x270 net/bluetooth/hci_request.c:109
hci_event_packet+0x963/0x1170 net/bluetooth/hci_event.c:7479
hci_rx_work+0x2c4/0x1610 net/bluetooth/hci_core.c:4074
process_one_work+0x9fb/0x1b60 kernel/workqueue.c:3231
process_scheduled_works kernel/workqueue.c:3312 [inline]
worker_thread+0x6c8/0xf70 kernel/workqueue.c:3393
kthread+0x2c1/0x3a0 kernel/kthread.c:389
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
</TASK>

Allocated by task 5317:
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_noprof+0x121/0x2f0 mm/slub.c:4008
skb_clone+0x190/0x3f0 net/core/skbuff.c:2052
hci_send_cmd_sync net/bluetooth/hci_core.c:4123 [inline]
hci_cmd_work+0x66a/0x710 net/bluetooth/hci_core.c:4143
process_one_work+0x9fb/0x1b60 kernel/workqueue.c:3231
process_scheduled_works kernel/workqueue.c:3312 [inline]
worker_thread+0x6c8/0xf70 kernel/workqueue.c:3393
kthread+0x2c1/0x3a0 kernel/kthread.c:389
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Freed by task 5306:
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
kfree_skbmem+0x10e/0x200 net/core/skbuff.c:1131
__kfree_skb net/core/skbuff.c:1188 [inline]
kfree_skb_reason+0x138/0x210 net/core/skbuff.c:1223
kfree_skb include/linux/skbuff.h:1257 [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+0x634/0x960 net/bluetooth/hci_core.c:787
hci_sock_ioctl+0x4f3/0x880 net/bluetooth/hci_sock.c:1150
sock_do_ioctl+0x116/0x280 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:907 [inline]
__se_sys_ioctl fs/ioctl.c:893 [inline]
__x64_sys_ioctl+0x193/0x220 fs/ioctl.c:893
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

The buggy address belongs to the object at ffff888025dce280
which belongs to the cache skbuff_head_cache of size 240
The buggy address is located 0 bytes inside of
240-byte region [ffff888025dce280, ffff888025dce370)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x25dce
head: order:1 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 ffff888018ed8780 dead000000000122 0000000000000000
raw: 0000000000000000 0000000080190019 00000001ffffefff 0000000000000000
head: 00fff00000000040 ffff888018ed8780 dead000000000122 0000000000000000
head: 0000000000000000 0000000080190019 00000001ffffefff 0000000000000000
head: 00fff00000000001 ffffea0000977381 ffffffffffffffff 0000000000000000
head: 0000000000000002 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 1, migratetype Unmovable, gfp_mask 0x152820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_HARDWALL), pid 5306, tgid 5306 (syz-executor.3), ts 70131626595, free_ts 69503653671
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_node_noprof+0xed/0x310 mm/slub.c:4044
__alloc_skb+0x2b1/0x380 net/core/skbuff.c:656
alloc_skb include/linux/skbuff.h:1308 [inline]
bt_skb_alloc include/net/bluetooth/bluetooth.h:489 [inline]
hci_prepare_cmd+0x32/0x2b0 net/bluetooth/hci_request.c:221
hci_req_add_ev+0x11b/0x2b0 net/bluetooth/hci_request.c:255
hci_scan_req+0x87/0x150 net/bluetooth/hci_core.c:73
__hci_req_sync+0x142/0x980 net/bluetooth/hci_request.c:130
hci_req_sync+0x97/0xd0 net/bluetooth/hci_request.c:206
hci_dev_cmd+0x634/0x960 net/bluetooth/hci_core.c:787
hci_sock_ioctl+0x4f3/0x880 net/bluetooth/hci_sock.c:1150
page last free pid 4688 tgid 4688 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1088 [inline]
free_unref_page+0x64a/0xe40 mm/page_alloc.c:2583
__put_partials+0x14c/0x170 mm/slub.c:2995
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x4e/0x140 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x192/0x1e0 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x69/0x90 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+0x121/0x2f0 mm/slub.c:4008
getname_flags.part.0+0x50/0x4f0 fs/namei.c:139
getname_flags+0x9b/0xf0 include/linux/audit.h:322
vfs_fstatat+0x9a/0x150 fs/stat.c:303
__do_sys_newfstatat+0xa6/0x130 fs/stat.c:468
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

Memory state around the buggy address:
ffff888025dce180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff888025dce200: 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc
>ffff888025dce280: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888025dce300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc
ffff888025dce380: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00
==================================================================

---
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