2023-11-16 11:20:43

by syzbot

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Subject: [syzbot] [bluetooth?] KASAN: slab-use-after-free Write in sco_sock_timeout

Hello,

syzbot found the following issue on:

HEAD commit: 8de1e7afcc1c Merge branch 'for-next/core' into for-kernelci
git tree: git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci
console output: https://syzkaller.appspot.com/x/log.txt?x=1126f190e80000
kernel config: https://syzkaller.appspot.com/x/.config?x=3e6feaeda5dcbc27
dashboard link: https://syzkaller.appspot.com/bug?extid=4c0d0c4cde787116d465
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: arm64
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=122a2560e80000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=136e08df680000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/0f00907f9764/disk-8de1e7af.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/0502fe78c60d/vmlinux-8de1e7af.xz
kernel image: https://storage.googleapis.com/syzbot-assets/192135168cc0/Image-8de1e7af.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: [email protected]

==================================================================
BUG: KASAN: slab-use-after-free in instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
BUG: KASAN: slab-use-after-free in atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:252 [inline]
BUG: KASAN: slab-use-after-free in __refcount_add include/linux/refcount.h:193 [inline]
BUG: KASAN: slab-use-after-free in __refcount_inc include/linux/refcount.h:250 [inline]
BUG: KASAN: slab-use-after-free in refcount_inc include/linux/refcount.h:267 [inline]
BUG: KASAN: slab-use-after-free in sock_hold include/net/sock.h:777 [inline]
BUG: KASAN: slab-use-after-free in sco_sock_timeout+0x64/0x25c net/bluetooth/sco.c:88
Write of size 4 at addr ffff0000dba59080 by task kworker/0:1/10

CPU: 0 PID: 10 Comm: kworker/0:1 Not tainted 6.6.0-rc7-syzkaller-g8de1e7afcc1c #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023
Workqueue: events sco_sock_timeout
Call trace:
dump_backtrace+0x1b8/0x1e4 arch/arm64/kernel/stacktrace.c:233
show_stack+0x2c/0x44 arch/arm64/kernel/stacktrace.c:240
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xd0/0x124 lib/dump_stack.c:106
print_address_description mm/kasan/report.c:364 [inline]
print_report+0x174/0x514 mm/kasan/report.c:475
kasan_report+0xd8/0x138 mm/kasan/report.c:588
kasan_check_range+0x254/0x294 mm/kasan/generic.c:187
__kasan_check_write+0x20/0x30 mm/kasan/shadow.c:37
instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:252 [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:777 [inline]
sco_sock_timeout+0x64/0x25c net/bluetooth/sco.c:88
process_one_work+0x694/0x1204 kernel/workqueue.c:2630
process_scheduled_works kernel/workqueue.c:2703 [inline]
worker_thread+0x938/0xef4 kernel/workqueue.c:2784
kthread+0x288/0x310 kernel/kthread.c:388
ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:857

Allocated by task 6180:
kasan_save_stack mm/kasan/common.c:45 [inline]
kasan_set_track+0x4c/0x7c mm/kasan/common.c:52
kasan_save_alloc_info+0x24/0x30 mm/kasan/generic.c:511
____kasan_kmalloc mm/kasan/common.c:374 [inline]
__kasan_kmalloc+0xac/0xc4 mm/kasan/common.c:383
kasan_kmalloc include/linux/kasan.h:198 [inline]
__do_kmalloc_node mm/slab_common.c:1026 [inline]
__kmalloc+0xcc/0x1b8 mm/slab_common.c:1039
kmalloc include/linux/slab.h:603 [inline]
sk_prot_alloc+0xc4/0x1f0 net/core/sock.c:2090
sk_alloc+0x44/0x3f4 net/core/sock.c:2143
bt_sock_alloc+0x4c/0x32c net/bluetooth/af_bluetooth.c:148
sco_sock_alloc net/bluetooth/sco.c:495 [inline]
sco_sock_create+0xbc/0x31c net/bluetooth/sco.c:526
bt_sock_create+0x14c/0x248 net/bluetooth/af_bluetooth.c:132
__sock_create+0x43c/0x884 net/socket.c:1569
sock_create net/socket.c:1620 [inline]
__sys_socket_create net/socket.c:1657 [inline]
__sys_socket+0x134/0x340 net/socket.c:1708
__do_sys_socket net/socket.c:1722 [inline]
__se_sys_socket net/socket.c:1720 [inline]
__arm64_sys_socket+0x7c/0x94 net/socket.c:1720
__invoke_syscall arch/arm64/kernel/syscall.c:37 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:51
el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:136
do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:155
el0_svc+0x54/0x158 arch/arm64/kernel/entry-common.c:678
el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:696
el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:595

Freed by task 6179:
kasan_save_stack mm/kasan/common.c:45 [inline]
kasan_set_track+0x4c/0x7c mm/kasan/common.c:52
kasan_save_free_info+0x38/0x5c mm/kasan/generic.c:522
____kasan_slab_free+0x144/0x1c0 mm/kasan/common.c:236
__kasan_slab_free+0x18/0x28 mm/kasan/common.c:244
kasan_slab_free include/linux/kasan.h:164 [inline]
slab_free_hook mm/slub.c:1800 [inline]
slab_free_freelist_hook mm/slub.c:1826 [inline]
slab_free mm/slub.c:3809 [inline]
__kmem_cache_free+0x2ac/0x480 mm/slub.c:3822
kfree+0xb8/0x19c mm/slab_common.c:1075
sk_prot_free net/core/sock.c:2126 [inline]
__sk_destruct+0x4c0/0x770 net/core/sock.c:2218
sk_destruct net/core/sock.c:2233 [inline]
__sk_free+0x37c/0x4e8 net/core/sock.c:2244
sk_free+0x60/0xc8 net/core/sock.c:2255
sock_put include/net/sock.h:1989 [inline]
sco_sock_kill+0xfc/0x1b4 net/bluetooth/sco.c:426
sco_sock_release+0x1fc/0x2c0 net/bluetooth/sco.c:1256
__sock_release net/socket.c:659 [inline]
sock_close+0xa4/0x1e8 net/socket.c:1419
__fput+0x324/0x7f8 fs/file_table.c:384
__fput_sync+0x60/0x9c fs/file_table.c:465
__do_sys_close fs/open.c:1572 [inline]
__se_sys_close fs/open.c:1557 [inline]
__arm64_sys_close+0x150/0x1e0 fs/open.c:1557
__invoke_syscall arch/arm64/kernel/syscall.c:37 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:51
el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:136
do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:155
el0_svc+0x54/0x158 arch/arm64/kernel/entry-common.c:678
el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:696
el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:595

The buggy address belongs to the object at ffff0000dba59000
which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 128 bytes inside of
freed 2048-byte region [ffff0000dba59000, ffff0000dba59800)

The buggy address belongs to the physical page:
page:00000000f24a79df refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11ba58
head:00000000f24a79df order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x5ffc00000000840(slab|head|node=0|zone=2|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 05ffc00000000840 ffff0000c0002000 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000080008 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
ffff0000dba58f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff0000dba59000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff0000dba59080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff0000dba59100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff0000dba59180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
------------[ cut here ]------------
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 0 PID: 10 at lib/refcount.c:25 refcount_warn_saturate+0x1a8/0x20c lib/refcount.c:25
Modules linked in:
CPU: 0 PID: 10 Comm: kworker/0:1 Tainted: G B 6.6.0-rc7-syzkaller-g8de1e7afcc1c #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023
Workqueue: events sco_sock_timeout
pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : refcount_warn_saturate+0x1a8/0x20c lib/refcount.c:25
lr : refcount_warn_saturate+0x1a8/0x20c lib/refcount.c:25
sp : ffff800092d57af0
x29: ffff800092d57af0 x28: 1fffe0001a9b5a4a x27: dfff800000000000
x26: ffff0000c1084008 x25: ffff0000d4dad250 x24: ffff0001b418b500
x23: dfff800000000000 x22: 0000000000000000 x21: 0000000000000002
x20: ffff0000dba59080 x19: ffff8000910a2000 x18: ffff800092d57800
x17: 0000000000000000 x16: ffff80008a71b23c x15: 0000000000000001
x14: 1ffff000125aaeb0 x13: 0000000000000000 x12: 0000000000000000
x11: 0000000000000001 x10: 0000000000000000 x9 : c0b0806111008b00
x8 : c0b0806111008b00 x7 : 0000000000000001 x6 : 0000000000000001
x5 : ffff800092d573d8 x4 : ffff80008e4210a0 x3 : ffff800082b180c4
x2 : 0000000000000001 x1 : 0000000000000001 x0 : 0000000000000000
Call trace:
refcount_warn_saturate+0x1a8/0x20c lib/refcount.c:25
__refcount_inc include/linux/refcount.h:250 [inline]
refcount_inc include/linux/refcount.h:267 [inline]
sock_hold include/net/sock.h:777 [inline]
sco_sock_timeout+0x19c/0x25c net/bluetooth/sco.c:88
process_one_work+0x694/0x1204 kernel/workqueue.c:2630
process_scheduled_works kernel/workqueue.c:2703 [inline]
worker_thread+0x938/0xef4 kernel/workqueue.c:2784
kthread+0x288/0x310 kernel/kthread.c:388
ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:857
irq event stamp: 29659
hardirqs last enabled at (29659): [<ffff80008a719090>] __exit_to_kernel_mode arch/arm64/kernel/entry-common.c:84 [inline]
hardirqs last enabled at (29659): [<ffff80008a719090>] exit_to_kernel_mode+0xdc/0x10c arch/arm64/kernel/entry-common.c:94
hardirqs last disabled at (29658): [<ffff800080021724>] __do_softirq+0x950/0xd54 kernel/softirq.c:569
softirqs last enabled at (19646): [<ffff800080021894>] softirq_handle_end kernel/softirq.c:399 [inline]
softirqs last enabled at (19646): [<ffff800080021894>] __do_softirq+0xac0/0xd54 kernel/softirq.c:582
softirqs last disabled at (19597): [<ffff80008002aadc>] ____do_softirq+0x14/0x20 arch/arm64/kernel/irq.c:80
---[ end trace 0000000000000000 ]---
------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: CPU: 0 PID: 10 at lib/refcount.c:28 refcount_warn_saturate+0x1c8/0x20c lib/refcount.c:28
Modules linked in:
CPU: 0 PID: 10 Comm: kworker/0:1 Tainted: G B W 6.6.0-rc7-syzkaller-g8de1e7afcc1c #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023
Workqueue: events sco_sock_timeout
pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : refcount_warn_saturate+0x1c8/0x20c lib/refcount.c:28
lr : refcount_warn_saturate+0x1c8/0x20c lib/refcount.c:28
sp : ffff800092d57af0
x29: ffff800092d57af0 x28: 1fffe0001a9b5a4a x27: dfff800000000000
x26: ffff0000c1084008 x25: ffff0000d4dad250 x24: ffff0001b418b500
x23: dfff800000000000 x22: 0000000000000000 x21: 0000000000000003
x20: ffff0000dba59080 x19: ffff8000910a2000 x18: ffff800092d57800
x17: 0000000000000000 x16: ffff80008a71b23c x15: 0000000000000001
x14: 1fffe0003682f032 x13: 0000000000000000 x12: 0000000000000000
x11: 0000000000000000 x10: 0000000000000000 x9 : c0b0806111008b00
x8 : c0b0806111008b00 x7 : 0000000000000001 x6 : 0000000000000001
x5 : ffff800092d573d8 x4 : ffff80008e4210a0 x3 : ffff8000805a359c
x2 : 0000000000000001 x1 : 0000000100000000 x0 : 0000000000000000
Call trace:
refcount_warn_saturate+0x1c8/0x20c lib/refcount.c:28
__refcount_sub_and_test include/linux/refcount.h:283 [inline]
__refcount_dec_and_test include/linux/refcount.h:315 [inline]
refcount_dec_and_test include/linux/refcount.h:333 [inline]
sock_put include/net/sock.h:1988 [inline]
sco_sock_timeout+0x1b0/0x25c net/bluetooth/sco.c:100
process_one_work+0x694/0x1204 kernel/workqueue.c:2630
process_scheduled_works kernel/workqueue.c:2703 [inline]
worker_thread+0x938/0xef4 kernel/workqueue.c:2784
kthread+0x288/0x310 kernel/kthread.c:388
ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:857
irq event stamp: 29659
hardirqs last enabled at (29659): [<ffff80008a719090>] __exit_to_kernel_mode arch/arm64/kernel/entry-common.c:84 [inline]
hardirqs last enabled at (29659): [<ffff80008a719090>] exit_to_kernel_mode+0xdc/0x10c arch/arm64/kernel/entry-common.c:94
hardirqs last disabled at (29658): [<ffff800080021724>] __do_softirq+0x950/0xd54 kernel/softirq.c:569
softirqs last enabled at (19646): [<ffff800080021894>] softirq_handle_end kernel/softirq.c:399 [inline]
softirqs last enabled at (19646): [<ffff800080021894>] __do_softirq+0xac0/0xd54 kernel/softirq.c:582
softirqs last disabled at (19597): [<ffff80008002aadc>] ____do_softirq+0x14/0x20 arch/arm64/kernel/irq.c:80
---[ end trace 0000000000000000 ]---


---
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