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
==================================================================