[syzbot] [pm?] KASAN: use-after-free Read in netdev_unregister_kobject

[syzbot] [pm?] KASAN: use-after-free Read in netdev_unregister_kobject

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    3cdb45594619 Merge tag 's390-6.9-4' of git://git.kernel.or..
git tree:       upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=13d23353180000
kernel config:  https://syzkaller.appspot.com/x/.config?x=d239903bd07761e5
dashboard link: https://syzkaller.appspot.com/bug?extid=6cf5652d3df49fae2e3f
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=172afcbf180000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=144067cb180000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/5135044ea611/disk-3cdb4559.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/3c5a5ab80ba8/vmlinux-3cdb4559.xz
kernel image: https://storage.googleapis.com/syzbot-assets/e215eb6531dd/bzImage-3cdb4559.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+6cf5652d3df49fae2e3f@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: use-after-free in device_for_each_child+0xa7/0x170 drivers/base/core.c:4044
Read of size 8 at addr ffff88807bee95f8 by task kbnepd bnep0/5202

CPU: 0 PID: 5202 Comm: kbnepd bnep0 Not tainted 6.9.0-rc4-syzkaller-00173-g3cdb45594619 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:488
 kasan_report+0x143/0x180 mm/kasan/report.c:601
 device_for_each_child+0xa7/0x170 drivers/base/core.c:4044
 pm_runtime_set_memalloc_noio+0x114/0x260 drivers/base/power/runtime.c:248
 netdev_unregister_kobject+0x178/0x250 net/core/net-sysfs.c:2106
 unregister_netdevice_many_notify+0x11dd/0x16e0 net/core/dev.c:11135
 unregister_netdevice_many net/core/dev.c:11163 [inline]
 unregister_netdevice_queue+0x303/0x370 net/core/dev.c:11042
 unregister_netdevice include/linux/netdevice.h:3115 [inline]
 unregister_netdev+0x1c/0x30 net/core/dev.c:11181
 bnep_session+0x2e09/0x3000 net/bluetooth/bnep/core.c:525
 kthread+0x2f2/0x390 kernel/kthread.c:388
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x400000000 pfn:0x7bee9
flags: 0xfff80000000000(node=0|zone=1|lastcpupid=0xfff)
page_type: 0xffffffff()
raw: 00fff80000000000 0000000000000000 dead000000000122 0000000000000000
raw: 0000000400000000 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 0x40dc0(GFP_KERNEL|__GFP_COMP|__GFP_ZERO), pid 5095, tgid -432259438 (syz-executor223), ts 5095, free_ts 96070220809
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1ea/0x210 mm/page_alloc.c:1534
 prep_new_page mm/page_alloc.c:1541 [inline]
 get_page_from_freelist+0x3410/0x35b0 mm/page_alloc.c:3317
 __alloc_pages+0x256/0x6c0 mm/page_alloc.c:4575
 __alloc_pages_node include/linux/gfp.h:238 [inline]
 alloc_pages_node include/linux/gfp.h:261 [inline]
 __kmalloc_large_node+0x91/0x1f0 mm/slub.c:3911
 __do_kmalloc_node mm/slub.c:3954 [inline]
 __kmalloc+0x320/0x4a0 mm/slub.c:3979
 kmalloc include/linux/slab.h:632 [inline]
 kzalloc include/linux/slab.h:749 [inline]
 hci_alloc_dev_priv+0x27/0x2030 net/bluetooth/hci_core.c:2500
 hci_alloc_dev include/net/bluetooth/hci_core.h:1672 [inline]
 __vhci_create_device drivers/bluetooth/hci_vhci.c:406 [inline]
 vhci_create_device+0x12e/0x720 drivers/bluetooth/hci_vhci.c:480
 vhci_get_user drivers/bluetooth/hci_vhci.c:537 [inline]
 vhci_write+0x3cb/0x480 drivers/bluetooth/hci_vhci.c:617
 call_write_iter include/linux/fs.h:2110 [inline]
 new_sync_write fs/read_write.c:497 [inline]
 vfs_write+0xa86/0xcb0 fs/read_write.c:590
 ksys_write+0x1a0/0x2c0 fs/read_write.c:643
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 5095 tgid 5095 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1141 [inline]
 free_unref_page_prepare+0x986/0xab0 mm/page_alloc.c:2347
 free_unref_page+0x37/0x3f0 mm/page_alloc.c:2487
 __folio_put_large+0x13f/0x190 mm/swap.c:132
 __folio_put+0x299/0x390 mm/swap.c:140
 folio_put include/linux/mm.h:1506 [inline]
 free_large_kmalloc+0x105/0x1c0 mm/slub.c:4361
 kfree+0x1ca/0x3a0 mm/slub.c:4384
 hci_release_dev+0x1516/0x16a0 net/bluetooth/hci_core.c:2833
 bt_host_release+0x83/0x90 net/bluetooth/hci_sysfs.c:94
 device_release+0x9b/0x1c0
 kobject_cleanup lib/kobject.c:689 [inline]
 kobject_release lib/kobject.c:720 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x231/0x480 lib/kobject.c:737
 vhci_release+0x8b/0xd0 drivers/bluetooth/hci_vhci.c:675
 __fput+0x42b/0x8a0 fs/file_table.c:422
 task_work_run+0x251/0x310 kernel/task_work.c:180
 exit_task_work include/linux/task_work.h:38 [inline]
 do_exit+0xa1b/0x27e0 kernel/exit.c:878
 do_group_exit+0x207/0x2c0 kernel/exit.c:1027
 __do_sys_exit_group kernel/exit.c:1038 [inline]
 __se_sys_exit_group kernel/exit.c:1036 [inline]
 __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1036

Memory state around the buggy address:
 ffff88807bee9480: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88807bee9500: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88807bee9580: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                                                ^
 ffff88807bee9600: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88807bee9680: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup

Re: [syzbot] [pm?] KASAN: use-after-free Read in netdev_unregister_kobject

[Hillf Danton]

On Mon, 22 Apr 2024 08:35:25 -0700
> syzbot found the following issue on:
> 
> HEAD commit:    3cdb45594619 Merge tag 's390-6.9-4' of git://git.kernel.or..
> git tree:       upstream
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=144067cb180000

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git  3cdb45594619

--- x/net/bluetooth/bnep/core.c
+++ y/net/bluetooth/bnep/core.c
@@ -659,7 +659,7 @@ int bnep_del_connection(struct bnep_conn
 	if (req->flags & ~valid_flags)
 		return -EINVAL;
 
-	down_read(&bnep_session_sem);
+	down_write(&bnep_session_sem);
 
 	s = __bnep_get_session(req->dst);
 	if (s) {
@@ -668,7 +668,7 @@ int bnep_del_connection(struct bnep_conn
 	} else
 		err = -ENOENT;
 
-	up_read(&bnep_session_sem);
+	up_write(&bnep_session_sem);
 	return err;
 }
 
--

Re: [syzbot] [pm?] KASAN: use-after-free Read in netdev_unregister_kobject

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KASAN: use-after-free Read in netdev_unregister_kobject

==================================================================
BUG: KASAN: use-after-free in device_for_each_child+0xa7/0x170 drivers/base/core.c:4044
Read of size 8 at addr ffff8880293555f8 by task kbnepd bnep0/5664

CPU: 0 PID: 5664 Comm: kbnepd bnep0 Not tainted 6.9.0-rc4-syzkaller-00173-g3cdb45594619-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:488
 kasan_report+0x143/0x180 mm/kasan/report.c:601
 device_for_each_child+0xa7/0x170 drivers/base/core.c:4044
 pm_runtime_set_memalloc_noio+0x114/0x260 drivers/base/power/runtime.c:248
 netdev_unregister_kobject+0x178/0x250 net/core/net-sysfs.c:2106
 unregister_netdevice_many_notify+0x11dd/0x16e0 net/core/dev.c:11135
 unregister_netdevice_many net/core/dev.c:11163 [inline]
 unregister_netdevice_queue+0x303/0x370 net/core/dev.c:11042
 unregister_netdevice include/linux/netdevice.h:3115 [inline]
 unregister_netdev+0x1c/0x30 net/core/dev.c:11181
 bnep_session+0x2e09/0x3000 net/bluetooth/bnep/core.c:525
 kthread+0x2f2/0x390 kernel/kthread.c:388
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x29355
flags: 0xfff80000000000(node=0|zone=1|lastcpupid=0xfff)
page_type: 0xffffffff()
raw: 00fff80000000000 ffffea0000a4d588 ffffea0000a4d508 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 0x140dc0(GFP_USER|__GFP_COMP|__GFP_ZERO), pid 5470, tgid 1627921193 (syz-executor.4), ts 5470, free_ts 128431373442
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1ea/0x210 mm/page_alloc.c:1534
 prep_new_page mm/page_alloc.c:1541 [inline]
 get_page_from_freelist+0x3410/0x35b0 mm/page_alloc.c:3317
 __alloc_pages+0x256/0x6c0 mm/page_alloc.c:4575
 __alloc_pages_node include/linux/gfp.h:238 [inline]
 alloc_pages_node include/linux/gfp.h:261 [inline]
 __kmalloc_large_node+0x91/0x1f0 mm/slub.c:3911
 __do_kmalloc_node mm/slub.c:3954 [inline]
 __kmalloc+0x320/0x4a0 mm/slub.c:3979
 kmalloc include/linux/slab.h:632 [inline]
 kzalloc include/linux/slab.h:749 [inline]
 hci_alloc_dev_priv+0x27/0x2030 net/bluetooth/hci_core.c:2500
 hci_alloc_dev include/net/bluetooth/hci_core.h:1672 [inline]
 __vhci_create_device drivers/bluetooth/hci_vhci.c:406 [inline]
 vhci_create_device+0x12e/0x720 drivers/bluetooth/hci_vhci.c:480
 vhci_get_user drivers/bluetooth/hci_vhci.c:537 [inline]
 vhci_write+0x3cb/0x480 drivers/bluetooth/hci_vhci.c:617
 call_write_iter include/linux/fs.h:2110 [inline]
 new_sync_write fs/read_write.c:497 [inline]
 vfs_write+0xa86/0xcb0 fs/read_write.c:590
 ksys_write+0x1a0/0x2c0 fs/read_write.c:643
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 5470 tgid 5470 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1141 [inline]
 free_unref_page_prepare+0x986/0xab0 mm/page_alloc.c:2347
 free_unref_page+0x37/0x3f0 mm/page_alloc.c:2487
 __folio_put_large+0x13f/0x190 mm/swap.c:132
 __folio_put+0x299/0x390 mm/swap.c:140
 folio_put include/linux/mm.h:1506 [inline]
 free_large_kmalloc+0x105/0x1c0 mm/slub.c:4361
 kfree+0x1ca/0x3a0 mm/slub.c:4384
 hci_release_dev+0x1516/0x16a0 net/bluetooth/hci_core.c:2833
 bt_host_release+0x83/0x90 net/bluetooth/hci_sysfs.c:94
 device_release+0x9b/0x1c0
 kobject_cleanup lib/kobject.c:689 [inline]
 kobject_release lib/kobject.c:720 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x231/0x480 lib/kobject.c:737
 vhci_release+0x8b/0xd0 drivers/bluetooth/hci_vhci.c:675
 __fput+0x42b/0x8a0 fs/file_table.c:422
 task_work_run+0x251/0x310 kernel/task_work.c:180
 exit_task_work include/linux/task_work.h:38 [inline]
 do_exit+0xa1b/0x27e0 kernel/exit.c:878
 do_group_exit+0x207/0x2c0 kernel/exit.c:1027
 __do_sys_exit_group kernel/exit.c:1038 [inline]
 __se_sys_exit_group kernel/exit.c:1036 [inline]
 __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1036

Memory state around the buggy address:
 ffff888029355480: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888029355500: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888029355580: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                                                ^
 ffff888029355600: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888029355680: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================


Tested on:

commit:         3cdb4559 Merge tag 's390-6.9-4' of git://git.kernel.or..
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=10c3d0d3180000
kernel config:  https://syzkaller.appspot.com/x/.config?x=d239903bd07761e5
dashboard link: https://syzkaller.appspot.com/bug?extid=6cf5652d3df49fae2e3f
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=105d6b20980000

Re: [syzbot] [pm?] KASAN: use-after-free Read in netdev_unregister_kobject

[Hillf Danton]

On Mon, 22 Apr 2024 08:35:25 -0700
> syzbot found the following issue on:
> 
> HEAD commit:    3cdb45594619 Merge tag 's390-6.9-4' of git://git.kernel.or..
> git tree:       upstream
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=144067cb180000

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git  3cdb45594619

--- x/net/bluetooth/bnep/core.c
+++ y/net/bluetooth/bnep/core.c
@@ -535,6 +535,7 @@ static int bnep_session(void *arg)
 	__bnep_unlink_session(s);
 
 	up_write(&bnep_session_sem);
+	put_device(dev->dev.parent);
 	free_netdev(dev);
 	module_put_and_kthread_exit(0);
 	return 0;
@@ -618,7 +619,7 @@ int bnep_add_connection(struct bnep_conn
 	bnep_set_default_proto_filter(s);
 #endif
 
-	SET_NETDEV_DEV(dev, bnep_get_device(s));
+	SET_NETDEV_DEV(dev, get_device(bnep_get_device(s)));
 	SET_NETDEV_DEVTYPE(dev, &bnep_type);
 
 	err = register_netdev(dev);
--

Re: [syzbot] [pm?] KASAN: use-after-free Read in netdev_unregister_kobject

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KASAN: out-of-bounds Read in netdev_unregister_kobject

==================================================================
BUG: KASAN: out-of-bounds in device_for_each_child+0xa7/0x170 drivers/base/core.c:4044
Read of size 8 at addr ffff88806e92d5f8 by task kbnepd bnep0/5637

CPU: 0 PID: 5637 Comm: kbnepd bnep0 Not tainted 6.9.0-rc4-syzkaller-00173-g3cdb45594619-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:488
 kasan_report+0x143/0x180 mm/kasan/report.c:601
 device_for_each_child+0xa7/0x170 drivers/base/core.c:4044
 pm_runtime_set_memalloc_noio+0x114/0x260 drivers/base/power/runtime.c:248
 netdev_unregister_kobject+0x178/0x250 net/core/net-sysfs.c:2106
 unregister_netdevice_many_notify+0x11dd/0x16e0 net/core/dev.c:11135
 unregister_netdevice_many net/core/dev.c:11163 [inline]
 unregister_netdevice_queue+0x303/0x370 net/core/dev.c:11042
 unregister_netdevice include/linux/netdevice.h:3115 [inline]
 unregister_netdev+0x1c/0x30 net/core/dev.c:11181
 bnep_session+0x2e09/0x3030 net/bluetooth/bnep/core.c:525
 kthread+0x2f2/0x390 kernel/kthread.c:388
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x6e92c
head: order:2 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff80000000040(head|node=0|zone=1|lastcpupid=0xfff)
page_type: 0xffffffff()
raw: 00fff80000000040 0000000000000000 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000
head: 00fff80000000040 0000000000000000 dead000000000122 0000000000000000
head: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000
head: 00fff80000000002 ffffea0001ba4b01 dead000000000122 00000000ffffffff
head: 0000000400000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0x140dc0(GFP_USER|__GFP_COMP|__GFP_ZERO), pid 5732, tgid -1102947349 (syz-executor.3), ts 5732, free_ts 127654865274
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1ea/0x210 mm/page_alloc.c:1534
 prep_new_page mm/page_alloc.c:1541 [inline]
 get_page_from_freelist+0x3410/0x35b0 mm/page_alloc.c:3317
 __alloc_pages+0x256/0x6c0 mm/page_alloc.c:4575
 __alloc_pages_node include/linux/gfp.h:238 [inline]
 alloc_pages_node include/linux/gfp.h:261 [inline]
 __kmalloc_large_node+0x91/0x1f0 mm/slub.c:3911
 __do_kmalloc_node mm/slub.c:3954 [inline]
 __kmalloc+0x320/0x4a0 mm/slub.c:3979
 kmalloc include/linux/slab.h:632 [inline]
 kzalloc include/linux/slab.h:749 [inline]
 hci_alloc_dev_priv+0x27/0x2030 net/bluetooth/hci_core.c:2500
 hci_alloc_dev include/net/bluetooth/hci_core.h:1672 [inline]
 __vhci_create_device drivers/bluetooth/hci_vhci.c:406 [inline]
 vhci_create_device+0x12e/0x720 drivers/bluetooth/hci_vhci.c:480
 vhci_get_user drivers/bluetooth/hci_vhci.c:537 [inline]
 vhci_write+0x3cb/0x480 drivers/bluetooth/hci_vhci.c:617
 call_write_iter include/linux/fs.h:2110 [inline]
 new_sync_write fs/read_write.c:497 [inline]
 vfs_write+0xa86/0xcb0 fs/read_write.c:590
 ksys_write+0x1a0/0x2c0 fs/read_write.c:643
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 5462 tgid 5462 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1141 [inline]
 free_unref_page_prepare+0x986/0xab0 mm/page_alloc.c:2347
 free_unref_page+0x37/0x3f0 mm/page_alloc.c:2487
 __folio_put_large+0x13f/0x190 mm/swap.c:132
 __folio_put+0x299/0x390 mm/swap.c:140
 folio_put include/linux/mm.h:1506 [inline]
 free_large_kmalloc+0x105/0x1c0 mm/slub.c:4361
 kfree+0x1ca/0x3a0 mm/slub.c:4384
 hci_release_dev+0x1516/0x16a0 net/bluetooth/hci_core.c:2833
 bt_host_release+0x83/0x90 net/bluetooth/hci_sysfs.c:94
 device_release+0x9b/0x1c0
 kobject_cleanup lib/kobject.c:689 [inline]
 kobject_release lib/kobject.c:720 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x231/0x480 lib/kobject.c:737
 vhci_release+0x8b/0xd0 drivers/bluetooth/hci_vhci.c:675
 __fput+0x42b/0x8a0 fs/file_table.c:422
 task_work_run+0x251/0x310 kernel/task_work.c:180
 exit_task_work include/linux/task_work.h:38 [inline]
 do_exit+0xa1b/0x27e0 kernel/exit.c:878
 do_group_exit+0x207/0x2c0 kernel/exit.c:1027
 __do_sys_exit_group kernel/exit.c:1038 [inline]
 __se_sys_exit_group kernel/exit.c:1036 [inline]
 __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1036

Memory state around the buggy address:
 ffff88806e92d500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88806e92d580: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88806e92d600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
                   ^
 ffff88806e92d680: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88806e92d700: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================


Tested on:

commit:         3cdb4559 Merge tag 's390-6.9-4' of git://git.kernel.or..
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=12f4cd9f180000
kernel config:  https://syzkaller.appspot.com/x/.config?x=d239903bd07761e5
dashboard link: https://syzkaller.appspot.com/bug?extid=6cf5652d3df49fae2e3f
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=124cca53180000

Re: [syzbot] [pm?] KASAN: use-after-free Read in netdev_unregister_kobject

[Hillf Danton]

On Mon, 22 Apr 2024 08:35:25 -0700
> syzbot found the following issue on:
> 
> HEAD commit:    3cdb45594619 Merge tag 's390-6.9-4' of git://git.kernel.or..
> git tree:       upstream
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=144067cb180000

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git  3cdb45594619

--- x/net/bluetooth/bnep/core.c
+++ y/net/bluetooth/bnep/core.c
@@ -540,16 +540,6 @@ static int bnep_session(void *arg)
 	return 0;
 }
 
-static struct device *bnep_get_device(struct bnep_session *session)
-{
-	struct l2cap_conn *conn = l2cap_pi(session->sock->sk)->chan->conn;
-
-	if (!conn || !conn->hcon)
-		return NULL;
-
-	return &conn->hcon->dev;
-}
-
 static const struct device_type bnep_type = {
 	.name	= "bluetooth",
 };
@@ -618,7 +608,6 @@ int bnep_add_connection(struct bnep_conn
 	bnep_set_default_proto_filter(s);
 #endif
 
-	SET_NETDEV_DEV(dev, bnep_get_device(s));
 	SET_NETDEV_DEVTYPE(dev, &bnep_type);
 
 	err = register_netdev(dev);
--

Re: [syzbot] [pm?] KASAN: use-after-free Read in netdev_unregister_kobject

[syzbot]

Hello,

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

Reported-and-tested-by: syzbot+6cf5652d3df49fae2e3f@syzkaller.appspotmail.com

Tested on:

commit:         3cdb4559 Merge tag 's390-6.9-4' of git://git.kernel.or..
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=119e4230980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=d239903bd07761e5
dashboard link: https://syzkaller.appspot.com/bug?extid=6cf5652d3df49fae2e3f
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=15e9a8d3180000

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

Re: [syzbot] [pm?] KASAN: use-after-free Read in netdev_unregister_kobject

[syzbot]

Hello,

syzbot tried to test the proposed patch but the build/boot failed:

failed to apply patch:
checking file net/bluetooth/hci_core.c
patch: **** unexpected end of file in patch



Tested on:

commit:         fb456083 Bluetooth: ISO: Fix UAF on iso_sock_timeout
git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth-next
kernel config:  https://syzkaller.appspot.com/x/.config?x=d239903bd07761e5
dashboard link: https://syzkaller.appspot.com/bug?extid=6cf5652d3df49fae2e3f
compiler:       
patch:          https://syzkaller.appspot.com/x/patch.diff?x=12c4f640580000

Re: [syzbot] [pm?] KASAN: use-after-free Read in netdev_unregister_kobject

[syzbot]

Hello,

syzbot tried to test the proposed patch but the build/boot failed:

failed to apply patch:
checking file net/bluetooth/hci_core.c
patch: **** unexpected end of file in patch



Tested on:

commit:         c2ee9f59 KVM: selftests: Fix build on on non-x86 archi..
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel config:  https://syzkaller.appspot.com/x/.config?x=d239903bd07761e5
dashboard link: https://syzkaller.appspot.com/bug?extid=6cf5652d3df49fae2e3f
compiler:       
patch:          https://syzkaller.appspot.com/x/patch.diff?x=1203665f980000

Re: [syzbot] [pm?] KASAN: use-after-free Read in netdev_unregister_kobject

[syzbot]

Hello,

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

Reported-by: syzbot+6cf5652d3df49fae2e3f@syzkaller.appspotmail.com
Tested-by: syzbot+6cf5652d3df49fae2e3f@syzkaller.appspotmail.com

Tested on:

commit:         6c52d4da Merge tag 'for-linus' of git://git.kernel.org..
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=121e5340580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=2cf68159adbdf217
dashboard link: https://syzkaller.appspot.com/bug?extid=6cf5652d3df49fae2e3f
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=107fe6f7980000

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

Re: [syzbot] [pm?] KASAN: use-after-free Read in netdev_unregister_kobject

[syzbot]

Hello,

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

Reported-by: syzbot+6cf5652d3df49fae2e3f@syzkaller.appspotmail.com
Tested-by: syzbot+6cf5652d3df49fae2e3f@syzkaller.appspotmail.com

Tested on:

commit:         dff8a642 Bluetooth: btrtl: Decrease HCI_OP_RESET timeo..
git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth-next
console output: https://syzkaller.appspot.com/x/log.txt?x=144816f7980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=36917d9184c65129
dashboard link: https://syzkaller.appspot.com/bug?extid=6cf5652d3df49fae2e3f
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=161c955f980000

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

Re: [syzbot] [pm?] KASAN: use-after-free Read in netdev_unregister_kobject

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KASAN: slab-use-after-free Read in netdev_unregister_kobject

==================================================================
BUG: KASAN: slab-use-after-free in device_for_each_child+0xbb/0x1b0 drivers/base/core.c:3999
Read of size 8 at addr ffff888021c81308 by task kbnepd bnep0/5597

CPU: 0 UID: 0 PID: 5597 Comm: kbnepd bnep0 Not tainted 6.12.0-rc5-syzkaller-00181-g6c52d4da1c74 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:488
 kasan_report+0x143/0x180 mm/kasan/report.c:601
 device_for_each_child+0xbb/0x1b0 drivers/base/core.c:3999
 pm_runtime_set_memalloc_noio+0x114/0x260 drivers/base/power/runtime.c:248
 netdev_unregister_kobject+0x178/0x250 net/core/net-sysfs.c:2109
 unregister_netdevice_many_notify+0x1851/0x1da0 net/core/dev.c:11441
 unregister_netdevice_many net/core/dev.c:11469 [inline]
 unregister_netdevice_queue+0x303/0x370 net/core/dev.c:11343
 unregister_netdevice include/linux/netdevice.h:3118 [inline]
 unregister_netdev+0x1c/0x30 net/core/dev.c:11487
 bnep_session+0x2e0e/0x3000 net/bluetooth/bnep/core.c:525
 kthread+0x2f2/0x390 kernel/kthread.c:389
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Allocated by task 5425:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
 __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394
 kasan_kmalloc include/linux/kasan.h:257 [inline]
 __do_kmalloc_node mm/slub.c:4264 [inline]
 __kmalloc_noprof+0x1fc/0x400 mm/slub.c:4276
 kmalloc_noprof include/linux/slab.h:882 [inline]
 kzalloc_noprof include/linux/slab.h:1014 [inline]
 hci_alloc_dev_priv+0x27/0x2030 net/bluetooth/hci_core.c:2440
 hci_alloc_dev include/net/bluetooth/hci_core.h:1621 [inline]
 __vhci_create_device drivers/bluetooth/hci_vhci.c:399 [inline]
 vhci_create_device+0x116/0x6a0 drivers/bluetooth/hci_vhci.c:470
 vhci_get_user drivers/bluetooth/hci_vhci.c:527 [inline]
 vhci_write+0x3cf/0x490 drivers/bluetooth/hci_vhci.c:607
 new_sync_write fs/read_write.c:590 [inline]
 vfs_write+0xaed/0xd30 fs/read_write.c:683
 ksys_write+0x183/0x2b0 fs/read_write.c:736
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 5425:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:230 [inline]
 slab_free_hook mm/slub.c:2342 [inline]
 slab_free mm/slub.c:4579 [inline]
 kfree+0x1a0/0x440 mm/slub.c:4727
 hci_release_dev+0x1525/0x16b0 net/bluetooth/hci_core.c:2759
 bt_host_release+0x83/0x90 net/bluetooth/hci_sysfs.c:94
 device_release+0x9b/0x1c0
 kobject_cleanup lib/kobject.c:689 [inline]
 kobject_release lib/kobject.c:720 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x231/0x480 lib/kobject.c:737
 vhci_release+0x88/0xd0 drivers/bluetooth/hci_vhci.c:665
 __fput+0x241/0x880 fs/file_table.c:431
 task_work_run+0x251/0x310 kernel/task_work.c:239
 exit_task_work include/linux/task_work.h:43 [inline]
 do_exit+0xa2f/0x28e0 kernel/exit.c:939
 do_group_exit+0x207/0x2c0 kernel/exit.c:1088
 __do_sys_exit_group kernel/exit.c:1099 [inline]
 __se_sys_exit_group kernel/exit.c:1097 [inline]
 __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1097
 x64_sys_call+0x2634/0x2640 arch/x86/include/generated/asm/syscalls_64.h:232
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Last potentially related work creation:
 kasan_save_stack+0x3f/0x60 mm/kasan/common.c:47
 __kasan_record_aux_stack+0xac/0xc0 mm/kasan/generic.c:541
 insert_work+0x3e/0x330 kernel/workqueue.c:2183
 __queue_work+0xb66/0xf50 kernel/workqueue.c:2343
 queue_work_on+0x1c2/0x380 kernel/workqueue.c:2390
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xa65/0x1850 kernel/workqueue.c:3310
 worker_thread+0x870/0xd30 kernel/workqueue.c:3391
 kthread+0x2f2/0x390 kernel/kthread.c:389
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Second to last potentially related work creation:
 kasan_save_stack+0x3f/0x60 mm/kasan/common.c:47
 __kasan_record_aux_stack+0xac/0xc0 mm/kasan/generic.c:541
 insert_work+0x3e/0x330 kernel/workqueue.c:2183
 __queue_work+0xc8b/0xf50 kernel/workqueue.c:2339
 call_timer_fn+0x190/0x650 kernel/time/timer.c:1794
 expire_timers kernel/time/timer.c:1840 [inline]
 __run_timers kernel/time/timer.c:2419 [inline]
 __run_timer_base+0x695/0x8e0 kernel/time/timer.c:2430
 run_timer_base kernel/time/timer.c:2439 [inline]
 run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2449
 handle_softirqs+0x2c7/0x980 kernel/softirq.c:554
 __do_softirq kernel/softirq.c:588 [inline]
 invoke_softirq kernel/softirq.c:428 [inline]
 __irq_exit_rcu+0xf4/0x1c0 kernel/softirq.c:637
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:649
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1049
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702

The buggy address belongs to the object at ffff888021c80000
 which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 4872 bytes inside of
 freed 8192-byte region [ffff888021c80000, ffff888021c82000)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x21c80
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
anon flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff888015442280 0000000000000000 0000000000000001
raw: 0000000000000000 0000000000020002 00000001f5000000 0000000000000000
head: 00fff00000000040 ffff888015442280 0000000000000000 0000000000000001
head: 0000000000000000 0000000000020002 00000001f5000000 0000000000000000
head: 00fff00000000003 ffffea0000872001 ffffffffffffffff 0000000000000000
head: 0000000000000008 0000000000000000 00000000ffffffff 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 0xd2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 4752, tgid 4752 (S40network), ts 32094841667, free_ts 32026397912
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1537
 prep_new_page mm/page_alloc.c:1545 [inline]
 get_page_from_freelist+0x303f/0x3190 mm/page_alloc.c:3457
 __alloc_pages_noprof+0x292/0x710 mm/page_alloc.c:4733
 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265
 alloc_slab_page+0x6a/0x120 mm/slub.c:2412
 allocate_slab+0x5a/0x2f0 mm/slub.c:2578
 new_slab mm/slub.c:2631 [inline]
 ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3818
 __slab_alloc+0x58/0xa0 mm/slub.c:3908
 __slab_alloc_node mm/slub.c:3961 [inline]
 slab_alloc_node mm/slub.c:4122 [inline]
 __kmalloc_cache_noprof+0x1d5/0x2c0 mm/slub.c:4290
 kmalloc_noprof include/linux/slab.h:878 [inline]
 kzalloc_noprof include/linux/slab.h:1014 [inline]
 tomoyo_print_bprm security/tomoyo/audit.c:26 [inline]
 tomoyo_init_log+0x11cd/0x2050 security/tomoyo/audit.c:264
 tomoyo_supervisor+0x38a/0x11f0 security/tomoyo/common.c:2089
 tomoyo_audit_env_log security/tomoyo/environ.c:36 [inline]
 tomoyo_env_perm+0x178/0x210 security/tomoyo/environ.c:63
 tomoyo_environ security/tomoyo/domain.c:672 [inline]
 tomoyo_find_next_domain+0x146e/0x1d40 security/tomoyo/domain.c:881
 tomoyo_bprm_check_security+0x114/0x180 security/tomoyo/tomoyo.c:102
 security_bprm_check+0x86/0x250 security/security.c:1297
 search_binary_handler fs/exec.c:1740 [inline]
 exec_binprm fs/exec.c:1794 [inline]
 bprm_execve+0xa56/0x1770 fs/exec.c:1845
page last free pid 4751 tgid 4751 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1108 [inline]
 free_unref_page+0xcfb/0xf20 mm/page_alloc.c:2638
 __slab_free+0x31b/0x3d0 mm/slub.c:4490
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329
 kasan_slab_alloc include/linux/kasan.h:247 [inline]
 slab_post_alloc_hook mm/slub.c:4085 [inline]
 slab_alloc_node mm/slub.c:4134 [inline]
 kmem_cache_alloc_noprof+0x135/0x2a0 mm/slub.c:4141
 vm_area_alloc+0x24/0x1d0 kernel/fork.c:472
 mmap_region+0x1134/0x2940 mm/mmap.c:1436
 do_mmap+0x8f0/0x1000 mm/mmap.c:496
 vm_mmap_pgoff+0x1dd/0x3d0 mm/util.c:588
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff888021c81200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888021c81280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888021c81300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                      ^
 ffff888021c81380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888021c81400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


Tested on:

commit:         6c52d4da Merge tag 'for-linus' of git://git.kernel.org..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=15e81630580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=2cf68159adbdf217
dashboard link: https://syzkaller.appspot.com/bug?extid=6cf5652d3df49fae2e3f
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

Note: no patches were applied.

Re: [syzbot] [pm?] KASAN: use-after-free Read in netdev_unregister_kobject

[syzbot]

Hello,

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

Reported-by: syzbot+6cf5652d3df49fae2e3f@syzkaller.appspotmail.com
Tested-by: syzbot+6cf5652d3df49fae2e3f@syzkaller.appspotmail.com

Tested on:

commit:         c4264568 Merge tag 'acpi-6.12-rc6' of git://git.kernel..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=148ad340580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=2cf68159adbdf217
dashboard link: https://syzkaller.appspot.com/bug?extid=6cf5652d3df49fae2e3f
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=1122d340580000

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