KASAN: use-after-free Write in tun_free_netdev

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: 93dc81bb ANDROID: GKI: scripts: Makefile: update the lz4 c..
git tree: android-5.4
console output: https://syzkaller.appspot.com/x/log.txt?x=16321cd5100000
kernel config: https://syzkaller.appspot.com/x/.config?x=ca0e7e103262f74f
dashboard link: https://syzkaller.appspot.com/bug?extid=b87a1e46946f6c65c622
compiler: Android (6032204 based on r370808) clang version 10.0.1 (https://android.googlesource.com/toolchain/llvm-project 6e765c10313d15c02ab29977a82938f66742c3a9)

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+b87a1e...@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: use-after-free in __hlist_del include/linux/list.h:764 [inline]
BUG: KASAN: use-after-free in detach_timer kernel/time/timer.c:815 [inline]
BUG: KASAN: use-after-free in detach_if_pending kernel/time/timer.c:832 [inline]
BUG: KASAN: use-after-free in try_to_del_timer_sync+0x3ee/0x480 kernel/time/timer.c:1226
Write of size 8 at addr ffff88816a0ef188 by task syz-executor.0/31594

CPU: 0 PID: 31594 Comm: syz-executor.0 Not tainted 5.4.50-syzkaller-01107-g93dc81bbbde5 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x14a/0x1ce lib/dump_stack.c:118
print_address_description+0x93/0x620 mm/kasan/report.c:374
__kasan_report+0x16d/0x1e0 mm/kasan/report.c:506
kasan_report+0x36/0x60 mm/kasan/common.c:634
__hlist_del include/linux/list.h:764 [inline]
detach_timer kernel/time/timer.c:815 [inline]
detach_if_pending kernel/time/timer.c:832 [inline]
try_to_del_timer_sync+0x3ee/0x480 kernel/time/timer.c:1226
del_timer_sync+0x74/0xe0 kernel/time/timer.c:1365
tun_flow_uninit drivers/net/tun.c:1374 [inline]
tun_free_netdev+0x99/0x3a0 drivers/net/tun.c:2307
netdev_run_todo+0xbe3/0xe90 net/core/dev.c:9351
tun_detach drivers/net/tun.c:743 [inline]
tun_chr_close+0xc0/0xd0 drivers/net/tun.c:3461
__fput+0x27d/0x6c0 fs/file_table.c:280
task_work_run+0x176/0x1a0 kernel/task_work.c:113
tracehook_notify_resume include/linux/tracehook.h:188 [inline]
exit_to_usermode_loop arch/x86/entry/common.c:163 [inline]
prepare_exit_to_usermode+0x286/0x2e0 arch/x86/entry/common.c:194
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x416721
Code: 75 14 b8 03 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 04 1b 00 00 c3 48 83 ec 08 e8 0a fc ff ff 48 89 04 24 b8 03 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 53 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01
RSP: 002b:00007ffcbd551570 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000005 RCX: 0000000000416721
RDX: 0000000000000000 RSI: 0000000000790418 RDI: 0000000000000004
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 00007ffcbd551660 R11: 0000000000000293 R12: 0000000000791590
R13: 00000000002304f2 R14: ffffffffffffffff R15: 000000000078c04c

The buggy address belongs to the page:
page:ffffea0005a83bc0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0
flags: 0x8000000000000000()
raw: 8000000000000000 ffffea00061d3608 ffffea0005a83b88 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
ffff88816a0ef080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff88816a0ef100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88816a0ef180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
^
ffff88816a0ef200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff88816a0ef280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================


---
This bug is generated by a bot. It may contain errors.
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[syzbot]

syzbot has found a reproducer for the following crash on:

HEAD commit: 45217b91 UPSTREAM: net: bpf: Make bpf_ktime_get_ns() avail..
git tree: android-5.4
console output: https://syzkaller.appspot.com/x/log.txt?x=1373a66d100000

kernel config: https://syzkaller.appspot.com/x/.config?x=ca0e7e103262f74f
dashboard link: https://syzkaller.appspot.com/bug?extid=b87a1e46946f6c65c622
compiler: Android (6032204 based on r370808) clang version 10.0.1 (https://android.googlesource.com/toolchain/llvm-project 6e765c10313d15c02ab29977a82938f66742c3a9)

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15784c05100000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+b87a1e...@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: use-after-free in __hlist_del include/linux/list.h:764 [inline]
BUG: KASAN: use-after-free in detach_timer kernel/time/timer.c:815 [inline]
BUG: KASAN: use-after-free in detach_if_pending kernel/time/timer.c:832 [inline]
BUG: KASAN: use-after-free in try_to_del_timer_sync+0x3ee/0x480 kernel/time/timer.c:1226

Write of size 8 at addr ffff8881ca35f188 by task syz-executor.0/22157

CPU: 1 PID: 22157 Comm: syz-executor.0 Not tainted 5.4.50-syzkaller-01110-g45217b91eaaa #0

RSP: 002b:00007ffcbb4b8c80 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000416721
RDX: 0000000000000001 RSI: 0000000000790300 RDI: 0000000000000003

RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000

R10: 00007ffcbb4b8d70 R11: 0000000000000293 R12: 0000000000791548
R13: 00000000000ecb36 R14: ffffffffffffffff R15: 000000000078bfac

The buggy address belongs to the page:

page:ffffea000728d7c0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0
flags: 0x8000000000000000()
raw: 8000000000000000 0000000000000000 ffffea000759ff08 0000000000000000

raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:

ffff8881ca35f080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff8881ca35f100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff8881ca35f180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
^
ffff8881ca35f200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff8881ca35f280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================

[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: f0306959ab7c ANDROID: ABI: Update symbols for unisoc
git tree: android12-5.4
console output: https://syzkaller.appspot.com/x/log.txt?x=137b32b3080000
kernel config: https://syzkaller.appspot.com/x/.config?x=d60ce76287fc97c0
dashboard link: https://syzkaller.appspot.com/bug?extid=b87a1e46946f6c65c622
compiler: Debian clang version 13.0.1-++20220126092033+75e33f71c2da-1~exp1~20220126212112.63, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1004bdb3080000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11eb0fc7080000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+b87a1e...@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: use-after-free in __hlist_del include/linux/list.h:773 [inline]
BUG: KASAN: use-after-free in detach_timer kernel/time/timer.c:824 [inline]
BUG: KASAN: use-after-free in detach_if_pending kernel/time/timer.c:841 [inline]
BUG: KASAN: use-after-free in try_to_del_timer_sync+0x2ad/0x460 kernel/time/timer.c:1238
Write of size 8 at addr ffff8881ea7631c8 by task syz-executor394/5895

CPU: 0 PID: 5895 Comm: syz-executor394 Not tainted 5.4.197-syzkaller-00015-gf0306959ab7c #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022

Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]

dump_stack+0x18e/0x1d5 lib/dump_stack.c:118
print_address_description+0x8c/0x630 mm/kasan/report.c:384
__kasan_report+0xf6/0x130 mm/kasan/report.c:516
kasan_report+0x30/0x60 mm/kasan/common.c:653
__hlist_del include/linux/list.h:773 [inline]
detach_timer kernel/time/timer.c:824 [inline]
detach_if_pending kernel/time/timer.c:841 [inline]
try_to_del_timer_sync+0x2ad/0x460 kernel/time/timer.c:1238
del_timer_sync+0x74/0xd0 kernel/time/timer.c:1379
tun_flow_uninit drivers/net/tun.c:1387 [inline]
tun_free_netdev+0x99/0x3b0 drivers/net/tun.c:2328
netdev_run_todo+0xa3c/0xc80 net/core/dev.c:9445
tun_detach drivers/net/tun.c:751 [inline]
tun_chr_close+0xc0/0xd0 drivers/net/tun.c:3523
__fput+0x261/0x680 fs/file_table.c:281
task_work_run+0x186/0x1b0 kernel/task_work.c:113
exit_task_work include/linux/task_work.h:22 [inline]
do_exit+0xbe1/0x2b40 kernel/exit.c:812
do_group_exit+0x136/0x300 kernel/exit.c:910
get_signal+0xd99/0x13f0 kernel/signal.c:2735
do_signal+0x3b/0x540 arch/x86/kernel/signal.c:809
exit_to_usermode_loop+0xdd/0x1d0 arch/x86/entry/common.c:159
prepare_exit_to_usermode+0x17c/0x1d0 arch/x86/entry/common.c:194
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f9e3b335a59
Code: Bad RIP value.
RSP: 002b:00007f9e3b2e7308 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: 0000000000000000 RBX: 00007f9e3b3bd3e8 RCX: 00007f9e3b335a59
RDX: 0000000020000040 RSI: 00000000400454ca RDI: 0000000000000003
RBP: 00007f9e3b3bd3e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f9e3b38b074
R13: 00007f9e3b3bd3ec R14: 74656e2f7665642f R15: 0000000000022000

The buggy address belongs to the page:

page:ffffea0007a9d8c0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0
flags: 0x8000000000000000()
raw: 8000000000000000 0000000000000000 ffffffff07a90101 0000000000000000

raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected

page_owner tracks the page as freed
page last allocated via order 2, migratetype Unmovable, gfp_mask 0x46dc0(GFP_KERNEL|__GFP_NOWARN|__GFP_RETRY_MAYFAIL|__GFP_COMP|__GFP_ZERO)
set_page_owner include/linux/page_owner.h:31 [inline]
post_alloc_hook mm/page_alloc.c:2165 [inline]
prep_new_page+0x194/0x380 mm/page_alloc.c:2171
get_page_from_freelist+0x524/0x560 mm/page_alloc.c:3794
__alloc_pages_nodemask+0x2ab/0x6f0 mm/page_alloc.c:4857
__alloc_pages include/linux/gfp.h:503 [inline]
__alloc_pages_node include/linux/gfp.h:516 [inline]
alloc_pages_node include/linux/gfp.h:530 [inline]
kmalloc_order mm/slab_common.c:1342 [inline]
kmalloc_order_trace+0x2a/0xf0 mm/slab_common.c:1358
__kmalloc_node include/linux/slab.h:422 [inline]
kmalloc_node include/linux/slab.h:599 [inline]
kvmalloc_node+0x7e/0xf0 mm/util.c:564
kvmalloc include/linux/mm.h:758 [inline]
kvzalloc include/linux/mm.h:766 [inline]
alloc_netdev_mqs+0x86/0xc30 net/core/dev.c:9597
tun_set_iff+0x4f9/0x1050 drivers/net/tun.c:2814
__tun_chr_ioctl+0x6c7/0x1b70 drivers/net/tun.c:3149
do_vfs_ioctl+0x6d1/0x15b0 fs/ioctl.c:47
ksys_ioctl fs/ioctl.c:742 [inline]
__do_sys_ioctl fs/ioctl.c:749 [inline]
__se_sys_ioctl fs/ioctl.c:747 [inline]
__x64_sys_ioctl+0xd4/0x110 fs/ioctl.c:747
do_syscall_64+0xcb/0x1c0 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x44/0xa9
page last free stack trace:
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1176 [inline]
__free_pages_ok+0x7ee/0x920 mm/page_alloc.c:1438
free_the_page mm/page_alloc.c:4919 [inline]
__free_pages+0x45/0x1e0 mm/page_alloc.c:4925
kfree+0x1ef/0x260 mm/slub.c:4068
device_release+0x70/0x1a0 drivers/base/core.c:1776
kobject_cleanup lib/kobject.c:708 [inline]
kobject_release+0x1f3/0x3d0 lib/kobject.c:739
netdev_run_todo+0xae7/0xc80 net/core/dev.c:9456
tun_detach drivers/net/tun.c:751 [inline]
tun_chr_close+0xc0/0xd0 drivers/net/tun.c:3523
__fput+0x261/0x680 fs/file_table.c:281
task_work_run+0x186/0x1b0 kernel/task_work.c:113
exit_task_work include/linux/task_work.h:22 [inline]
do_exit+0xbe1/0x2b40 kernel/exit.c:812
do_group_exit+0x136/0x300 kernel/exit.c:910
get_signal+0xd99/0x13f0 kernel/signal.c:2735
do_signal+0x3b/0x540 arch/x86/kernel/signal.c:809
exit_to_usermode_loop+0xdd/0x1d0 arch/x86/entry/common.c:159
prepare_exit_to_usermode+0x17c/0x1d0 arch/x86/entry/common.c:194
entry_SYSCALL_64_after_hwframe+0x44/0xa9

Memory state around the buggy address:

ffff8881ea763080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff8881ea763100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff8881ea763180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
^
ffff8881ea763200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff8881ea763280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================