[syzbot] [kernel?] KASAN: slab-use-after-free Read in binder_release_work

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: ad46e8f95e93 Merge tag 'pm-6.12-rc1-2' of git://git.kernel..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=16415e80580000
kernel config: https://syzkaller.appspot.com/x/.config?x=4a1ec17f68be97c
dashboard link: https://syzkaller.appspot.com/bug?extid=9ba7a8cdae0440edd57b
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=13f24d9f980000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=10ff3507980000

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7feb34a89c2a/non_bootable_disk-ad46e8f9.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/fc370c55f9af/vmlinux-ad46e8f9.xz
kernel image: https://storage.googleapis.com/syzbot-assets/faf0e295018c/bzImage-ad46e8f9.xz

The issue was bisected to:

commit de79583ffe794663c53b77f97be814522d4edc4f
Author: Nuno Sa <nun...@analog.com>
Date: Tue Jul 2 16:02:33 2024 +0000

iio: core: add accessors 'masklength'

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=11e42d9f980000
final oops: https://syzkaller.appspot.com/x/report.txt?x=13e42d9f980000
console output: https://syzkaller.appspot.com/x/log.txt?x=15e42d9f980000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9ba7a8...@syzkaller.appspotmail.com
Fixes: de79583ffe79 ("iio: core: add accessors 'masklength'")

BUG: KASAN: slab-use-after-free in __list_del_entry_valid_or_report+0x14c/0x1c0 lib/list_debug.c:49
Read of size 8 at addr ffff8880241da108 by task kworker/2:1/69

CPU: 2 UID: 0 PID: 69 Comm: kworker/2:1 Not tainted 6.11.0-syzkaller-11728-gad46e8f95e93 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Workqueue: events binder_deferred_func
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:377 [inline]
print_report+0xc3/0x620 mm/kasan/report.c:488
kasan_report+0xd9/0x110 mm/kasan/report.c:601
__list_del_entry_valid_or_report+0x14c/0x1c0 lib/list_debug.c:49
__list_del_entry_valid include/linux/list.h:124 [inline]
__list_del_entry include/linux/list.h:215 [inline]
list_del_init include/linux/list.h:287 [inline]
binder_dequeue_work_head_ilocked drivers/android/binder.c:540 [inline]
binder_release_work+0x9b/0x490 drivers/android/binder.c:5110
binder_deferred_release drivers/android/binder.c:6261 [inline]
binder_deferred_func+0xe6e/0x12e0 drivers/android/binder.c:6296
process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3229
process_scheduled_works kernel/workqueue.c:3310 [inline]
worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391
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 5330:
kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
kasan_save_track+0x14/0x30 mm/kasan/common.c:68
poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
__kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394
kmalloc_noprof include/linux/slab.h:878 [inline]
kzalloc_noprof include/linux/slab.h:1014 [inline]
binder_request_freeze_notification drivers/android/binder.c:3855 [inline]
binder_thread_write+0xe19/0x4c60 drivers/android/binder.c:4485
binder_ioctl_write_read drivers/android/binder.c:5387 [inline]
binder_ioctl+0x265b/0x6fa0 drivers/android/binder.c:5718
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+0x18f/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

Freed by task 69:
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 mm/kasan/common.c:247 [inline]
__kasan_slab_free+0x51/0x70 mm/kasan/common.c:264
kasan_slab_free include/linux/kasan.h:230 [inline]
slab_free_hook mm/slub.c:2343 [inline]
slab_free mm/slub.c:4580 [inline]
kfree+0x14f/0x4b0 mm/slub.c:4728
binder_free_ref drivers/android/binder.c:1355 [inline]
binder_deferred_release drivers/android/binder.c:6256 [inline]
binder_deferred_func+0xdd7/0x12e0 drivers/android/binder.c:6296
process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3229
process_scheduled_works kernel/workqueue.c:3310 [inline]
worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391
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

The buggy address belongs to the object at ffff8880241da100
which belongs to the cache kmalloc-64 of size 64
The buggy address is located 8 bytes inside of
freed 64-byte region [ffff8880241da100, ffff8880241da140)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x241da
ksm flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000000 ffff88801b0428c0 ffffea00009e6c40 dead000000000003
raw: 0000000000000000 0000000080200020 00000001f5000000 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x52cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 11, tgid 11 (kworker/u32:0), ts 6002017763, free_ts 5976749714
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x2d1/0x350 mm/page_alloc.c:1537
prep_new_page mm/page_alloc.c:1545 [inline]
get_page_from_freelist+0x101e/0x3070 mm/page_alloc.c:3457
__alloc_pages_noprof+0x223/0x25c0 mm/page_alloc.c:4733
alloc_pages_mpol_noprof+0x2c9/0x610 mm/mempolicy.c:2265
alloc_slab_page mm/slub.c:2413 [inline]
allocate_slab mm/slub.c:2579 [inline]
new_slab+0x2ba/0x3f0 mm/slub.c:2632
___slab_alloc+0xdac/0x1880 mm/slub.c:3819
__slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3909
__slab_alloc_node mm/slub.c:3962 [inline]
slab_alloc_node mm/slub.c:4123 [inline]
__kmalloc_cache_node_noprof+0xf1/0x350 mm/slub.c:4304
kmalloc_node_noprof include/linux/slab.h:901 [inline]
__get_vm_area_node+0xe1/0x2d0 mm/vmalloc.c:3106
__vmalloc_node_range_noprof+0x26a/0x15a0 mm/vmalloc.c:3788
alloc_thread_stack_node kernel/fork.c:314 [inline]
dup_task_struct kernel/fork.c:1115 [inline]
copy_process+0x2f12/0x8dc0 kernel/fork.c:2206
kernel_clone+0xfd/0x960 kernel/fork.c:2787
user_mode_thread+0xb4/0xf0 kernel/fork.c:2865
call_usermodehelper_exec_work kernel/umh.c:172 [inline]
call_usermodehelper_exec_work+0xcb/0x170 kernel/umh.c:158
process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3229
process_scheduled_works kernel/workqueue.c:3310 [inline]
worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391
page last free pid 9 tgid 9 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1108 [inline]
free_unref_page+0x5f4/0xdc0 mm/page_alloc.c:2638
vfree+0x17a/0x890 mm/vmalloc.c:3361
delayed_vfree_work+0x56/0x70 mm/vmalloc.c:3282
process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3229
process_scheduled_works kernel/workqueue.c:3310 [inline]
worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391
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

Memory state around the buggy address:
ffff8880241da000: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
ffff8880241da080: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
>ffff8880241da100: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
^
ffff8880241da180: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
ffff8880241da200: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
==================================================================


---
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[Hillf Danton]

On Wed, 02 Oct 2024 14:10:22 -0700

> syzbot found the following issue on:
>
> HEAD commit: ad46e8f95e93 Merge tag 'pm-6.12-rc1-2' of git://git.kernel..
> git tree: upstream

> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=10ff3507980000

#syz test

--- x/drivers/android/binder.c
+++ y/drivers/android/binder.c
@@ -6252,6 +6252,7 @@ static void binder_deferred_release(stru
ref = rb_entry(n, struct binder_ref, rb_node_desc);
outgoing_refs++;
binder_cleanup_ref_olocked(ref);
+ binder_dequeue_work(proc, &ref->freeze->work);
binder_proc_unlock(proc);
binder_free_ref(ref);
binder_proc_lock(proc);
--

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-by: syzbot+9ba7a8...@syzkaller.appspotmail.com
Tested-by: syzbot+9ba7a8...@syzkaller.appspotmail.com

Tested on:

commit: 7ec46210 Merge tag 'pull-work.unaligned' of git://git...
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=13f22307980000
kernel config: https://syzkaller.appspot.com/x/.config?x=6248f0ab12f33349

dashboard link: https://syzkaller.appspot.com/bug?extid=9ba7a8cdae0440edd57b
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40

patch: https://syzkaller.appspot.com/x/patch.diff?x=1005339f980000

Note: testing is done by a robot and is best-effort only.