Hello,
syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KASAN: use-after-free Write in sco_sock_timeout
==================================================================
BUG: KASAN: use-after-free in instrument_atomic_read_write include/linux/instrumented.h:101 [inline]
BUG: KASAN: use-after-free in atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:116 [inline]
BUG: KASAN: use-after-free in __refcount_add include/linux/refcount.h:193 [inline]
BUG: KASAN: use-after-free in __refcount_inc include/linux/refcount.h:250 [inline]
BUG: KASAN: use-after-free in refcount_inc include/linux/refcount.h:267 [inline]
BUG: KASAN: use-after-free in sock_hold include/net/sock.h:726 [inline]
BUG: KASAN: use-after-free in sco_sock_timeout+0x64/0x290 net/bluetooth/sco.c:89
Write of size 4 at addr ffff88801d165080 by task kworker/0:1/8
CPU: 0 PID: 8 Comm: kworker/0:1 Not tainted 5.17.0-rc4-syzkaller-01424-g922ea87ff6f2-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events sco_sock_timeout
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
print_address_description.constprop.0.cold+0x8d/0x336 mm/kasan/report.c:255
__kasan_report mm/kasan/report.c:442 [inline]
kasan_report.cold+0x83/0xdf mm/kasan/report.c:459
check_region_inline mm/kasan/generic.c:183 [inline]
kasan_check_range+0x13d/0x180 mm/kasan/generic.c:189
instrument_atomic_read_write include/linux/instrumented.h:101 [inline]
atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:116 [inline]
__refcount_add include/linux/refcount.h:193 [inline]
__refcount_inc include/linux/refcount.h:250 [inline]
refcount_inc include/linux/refcount.h:267 [inline]
sock_hold include/net/sock.h:726 [inline]
sco_sock_timeout+0x64/0x290 net/bluetooth/sco.c:89
process_one_work+0x9ac/0x1650 kernel/workqueue.c:2307
worker_thread+0x657/0x1110 kernel/workqueue.c:2454
kthread+0x2e9/0x3a0 kernel/kthread.c:377
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
</TASK>
Allocated by task 4059:
kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38
kasan_set_track mm/kasan/common.c:45 [inline]
set_alloc_info mm/kasan/common.c:436 [inline]
____kasan_kmalloc mm/kasan/common.c:515 [inline]
____kasan_kmalloc mm/kasan/common.c:474 [inline]
__kasan_kmalloc+0xa9/0xd0 mm/kasan/common.c:524
kmalloc include/linux/slab.h:586 [inline]
sk_prot_alloc+0x110/0x290 net/core/sock.c:1936
sk_alloc+0x32/0xa80 net/core/sock.c:1989
sco_sock_alloc.constprop.0+0x31/0x330 net/bluetooth/sco.c:484
sco_sock_create+0xd5/0x1b0 net/bluetooth/sco.c:523
bt_sock_create+0x17c/0x340 net/bluetooth/af_bluetooth.c:130
__sock_create+0x353/0x790 net/socket.c:1468
sock_create net/socket.c:1519 [inline]
__sys_socket+0xef/0x200 net/socket.c:1561
__do_sys_socket net/socket.c:1570 [inline]
__se_sys_socket net/socket.c:1568 [inline]
__x64_sys_socket+0x6f/0xb0 net/socket.c:1568
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
Freed by task 4060:
kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38
kasan_set_track+0x21/0x30 mm/kasan/common.c:45
kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370
____kasan_slab_free mm/kasan/common.c:366 [inline]
____kasan_slab_free+0x126/0x160 mm/kasan/common.c:328
kasan_slab_free include/linux/kasan.h:236 [inline]
slab_free_hook mm/slub.c:1728 [inline]
slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1754
slab_free mm/slub.c:3509 [inline]
kfree+0xd0/0x390 mm/slub.c:4562
sk_prot_free net/core/sock.c:1972 [inline]
__sk_destruct+0x6c0/0x920 net/core/sock.c:2058
sk_destruct+0x131/0x180 net/core/sock.c:2076
__sk_free+0xef/0x3d0 net/core/sock.c:2087
sk_free+0x78/0xa0 net/core/sock.c:2098
sock_put include/net/sock.h:1926 [inline]
sco_sock_kill+0x18d/0x1b0 net/bluetooth/sco.c:403
sco_sock_release+0x162/0x2d0 net/bluetooth/sco.c:1260
__sock_release+0xcd/0x280 net/socket.c:650
sock_close+0x18/0x20 net/socket.c:1318
__fput+0x286/0x9f0 fs/file_table.c:317
task_work_run+0xdd/0x1a0 kernel/task_work.c:164
get_signal+0x1de2/0x2490 kernel/signal.c:2631
arch_do_signal_or_restart+0x2a9/0x1c40 arch/x86/kernel/signal.c:868
handle_signal_work kernel/entry/common.c:148 [inline]
exit_to_user_mode_loop kernel/entry/common.c:172 [inline]
exit_to_user_mode_prepare+0x17d/0x290 kernel/entry/common.c:207
__syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline]
syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300
do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x44/0xae
Last potentially related work creation:
kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38
__kasan_record_aux_stack+0xbe/0xd0 mm/kasan/generic.c:348
__call_rcu kernel/rcu/tree.c:3026 [inline]
call_rcu+0xb1/0x740 kernel/rcu/tree.c:3106
netlink_release+0xf08/0x1db0 net/netlink/af_netlink.c:813
__sock_release+0xcd/0x280 net/socket.c:650
sock_close+0x18/0x20 net/socket.c:1318
__fput+0x286/0x9f0 fs/file_table.c:317
task_work_run+0xdd/0x1a0 kernel/task_work.c:164
tracehook_notify_resume include/linux/tracehook.h:188 [inline]
exit_to_user_mode_loop kernel/entry/common.c:175 [inline]
exit_to_user_mode_prepare+0x27e/0x290 kernel/entry/common.c:207
__syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline]
syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300
do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x44/0xae
Second to last potentially related work creation:
kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38
__kasan_record_aux_stack+0xbe/0xd0 mm/kasan/generic.c:348
__call_rcu kernel/rcu/tree.c:3026 [inline]
call_rcu+0xb1/0x740 kernel/rcu/tree.c:3106
netlink_release+0xf08/0x1db0 net/netlink/af_netlink.c:813
__sock_release+0xcd/0x280 net/socket.c:650
sock_close+0x18/0x20 net/socket.c:1318
__fput+0x286/0x9f0 fs/file_table.c:317
task_work_run+0xdd/0x1a0 kernel/task_work.c:164
tracehook_notify_resume include/linux/tracehook.h:188 [inline]
exit_to_user_mode_loop kernel/entry/common.c:175 [inline]
exit_to_user_mode_prepare+0x27e/0x290 kernel/entry/common.c:207
__syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline]
syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300
do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x44/0xae
The buggy address belongs to the object at ffff88801d165000
which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 128 bytes inside of
2048-byte region [ffff88801d165000, ffff88801d165800)
The buggy address belongs to the page:
page:ffffea0000745800 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1d160
head:ffffea0000745800 order:3 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 ffffea000070c000 dead000000000002 ffff888010c42000
raw: 0000000000000000 0000000000080008 00000001ffffffff 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 54, ts 8464675040, free_ts 0
prep_new_page mm/page_alloc.c:2434 [inline]
get_page_from_freelist+0xa72/0x2f50 mm/page_alloc.c:4165
__alloc_pages+0x1b2/0x500 mm/page_alloc.c:5389
alloc_pages+0x1aa/0x310 mm/mempolicy.c:2271
alloc_slab_page mm/slub.c:1799 [inline]
allocate_slab+0x27f/0x3c0 mm/slub.c:1944
new_slab mm/slub.c:2004 [inline]
___slab_alloc+0xbe1/0x12b0 mm/slub.c:3018
__slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3105
slab_alloc_node mm/slub.c:3196 [inline]
slab_alloc mm/slub.c:3238 [inline]
__kmalloc+0x372/0x450 mm/slub.c:4420
kmalloc include/linux/slab.h:586 [inline]
kzalloc include/linux/slab.h:715 [inline]
scsi_alloc_target+0x132/0xc60 drivers/scsi/scsi_scan.c:498
__scsi_scan_target+0x13a/0xdb0 drivers/scsi/scsi_scan.c:1632
scsi_scan_channel drivers/scsi/scsi_scan.c:1737 [inline]
scsi_scan_channel+0x148/0x1e0 drivers/scsi/scsi_scan.c:1713
scsi_scan_host_selected+0x2df/0x3b0 drivers/scsi/scsi_scan.c:1766
do_scsi_scan_host+0x1e8/0x260 drivers/scsi/scsi_scan.c:1905
do_scan_async+0x3e/0x500 drivers/scsi/scsi_scan.c:1915
async_run_entry_fn+0x9d/0x550 kernel/async.c:127
process_one_work+0x9ac/0x1650 kernel/workqueue.c:2307
worker_thread+0x657/0x1110 kernel/workqueue.c:2454
page_owner free stack trace missing
Memory state around the buggy address:
ffff88801d164f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff88801d165000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88801d165080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88801d165100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88801d165180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
Tested on:
commit: 922ea87f ionic: use vmalloc include
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=144f85da700000
kernel config: https://syzkaller.appspot.com/x/.config?x=d63ad23bb09039e8
dashboard link: https://syzkaller.appspot.com/bug?extid=2bef95d3ab4daa10155b
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
patch: https://syzkaller.appspot.com/x/patch.diff?x=16e9136c700000
