[syzbot] KASAN: use-after-free Read in r871xu_dev_remove

[syzbot] KASAN: use-after-free Read in r871xu_dev_remove

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    92510a7f Add linux-next specific files for 20210709
git tree:       linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=16c50180300000
kernel config:  https://syzkaller.appspot.com/x/.config?x=505de2716f052686
dashboard link: https://syzkaller.appspot.com/bug?extid=5872a520e0ce0a7c7230
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1639a73c300000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=15fcd5e4300000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+5872a520e0ce0a7c7230@syzkaller.appspotmail.com

usb 1-1: USB disconnect, device number 14
==================================================================
BUG: KASAN: use-after-free in __lock_acquire+0x3d86/0x54a0 kernel/locking/lockdep.c:4885
Read of size 8 at addr ffff888038bbce28 by task kworker/1:2/4393

CPU: 1 PID: 4393 Comm: kworker/1:2 Not tainted 5.13.0-next-20210709-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: usb_hub_wq hub_event
Call Trace:
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:105
 print_address_description.constprop.0.cold+0x6c/0x309 mm/kasan/report.c:233
 __kasan_report mm/kasan/report.c:419 [inline]
 kasan_report.cold+0x83/0xdf mm/kasan/report.c:436
 __lock_acquire+0x3d86/0x54a0 kernel/locking/lockdep.c:4885
 lock_acquire kernel/locking/lockdep.c:5625 [inline]
 lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5590
 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline]
 _raw_spin_lock_irq+0x32/0x50 kernel/locking/spinlock.c:167
 do_wait_for_common kernel/sched/completion.c:86 [inline]
 __wait_for_common kernel/sched/completion.c:106 [inline]
 wait_for_common kernel/sched/completion.c:117 [inline]
 wait_for_completion+0x181/0x280 kernel/sched/completion.c:138
 r871xu_dev_remove+0x80/0x320 drivers/staging/rtl8712/usb_intf.c:599
 usb_unbind_interface+0x1d8/0x8d0 drivers/usb/core/driver.c:458
 __device_release_driver+0x3bd/0x6f0 drivers/base/dd.c:1201
 device_release_driver_internal drivers/base/dd.c:1232 [inline]
 device_release_driver+0x26/0x40 drivers/base/dd.c:1255
 bus_remove_device+0x2eb/0x5a0 drivers/base/bus.c:529
 device_del+0x502/0xd40 drivers/base/core.c:3544
 usb_disable_device+0x35b/0x7b0 drivers/usb/core/message.c:1419
 usb_disconnect.cold+0x27a/0x78e drivers/usb/core/hub.c:2221
 hub_port_connect drivers/usb/core/hub.c:5151 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5440 [inline]
 port_event drivers/usb/core/hub.c:5586 [inline]
 hub_event+0x1c9c/0x4330 drivers/usb/core/hub.c:5668
 process_one_work+0x98d/0x1630 kernel/workqueue.c:2276
 worker_thread+0x658/0x11f0 kernel/workqueue.c:2422
 kthread+0x3e5/0x4d0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

Allocated by task 4860:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 __kasan_slab_alloc+0x84/0xa0 mm/kasan/common.c:467
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slab.h:512 [inline]
 slab_alloc_node mm/slub.c:2981 [inline]
 slab_alloc mm/slub.c:2989 [inline]
 kmem_cache_alloc+0x216/0x3a0 mm/slub.c:2994
 getname_flags.part.0+0x50/0x4f0 fs/namei.c:138
 getname_flags fs/namei.c:2747 [inline]
 user_path_at_empty+0xa1/0x100 fs/namei.c:2747
 user_path_at include/linux/namei.h:57 [inline]
 vfs_statx+0x142/0x390 fs/stat.c:203
 vfs_fstatat fs/stat.c:225 [inline]
 vfs_lstat include/linux/fs.h:3426 [inline]
 __do_sys_newlstat+0x91/0x110 fs/stat.c:380
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Freed by task 4860:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
 kasan_set_track+0x1c/0x30 mm/kasan/common.c:46
 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:360
 ____kasan_slab_free mm/kasan/common.c:366 [inline]
 ____kasan_slab_free mm/kasan/common.c:328 [inline]
 __kasan_slab_free+0xfb/0x130 mm/kasan/common.c:374
 kasan_slab_free include/linux/kasan.h:229 [inline]
 slab_free_hook mm/slub.c:1650 [inline]
 slab_free_freelist_hook+0xdf/0x240 mm/slub.c:1675
 slab_free mm/slub.c:3235 [inline]
 kmem_cache_free+0x8e/0x5a0 mm/slub.c:3251
 putname+0xe1/0x120 fs/namei.c:259
 filename_lookup+0x3df/0x5b0 fs/namei.c:2477
 user_path_at include/linux/namei.h:57 [inline]
 vfs_statx+0x142/0x390 fs/stat.c:203
 vfs_fstatat fs/stat.c:225 [inline]
 vfs_lstat include/linux/fs.h:3426 [inline]
 __do_sys_newlstat+0x91/0x110 fs/stat.c:380
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

The buggy address belongs to the object at ffff888038bbc400
 which belongs to the cache names_cache of size 4096
The buggy address is located 2600 bytes inside of
 4096-byte region [ffff888038bbc400, ffff888038bbd400)
The buggy address belongs to the page:
page:ffffea0000e2ee00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x38bb8
head:ffffea0000e2ee00 order:3 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 0000000000000000 dead000000000122 ffff8880109c43c0
raw: 0000000000000000 0000000000070007 00000001ffffffff 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 4860, ts 1160993662069, free_ts 1160991389825
 prep_new_page mm/page_alloc.c:2444 [inline]
 get_page_from_freelist+0xa72/0x2f80 mm/page_alloc.c:4177
 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5385
 alloc_pages+0x18c/0x2a0 mm/mempolicy.c:2244
 alloc_slab_page mm/slub.c:1713 [inline]
 allocate_slab+0x32b/0x4c0 mm/slub.c:1853
 new_slab mm/slub.c:1916 [inline]
 new_slab_objects mm/slub.c:2662 [inline]
 ___slab_alloc+0x4ba/0x820 mm/slub.c:2825
 __slab_alloc.constprop.0+0xa7/0xf0 mm/slub.c:2865
 slab_alloc_node mm/slub.c:2947 [inline]
 slab_alloc mm/slub.c:2989 [inline]
 kmem_cache_alloc+0x372/0x3a0 mm/slub.c:2994
 getname_flags.part.0+0x50/0x4f0 fs/namei.c:138
 getname_flags fs/namei.c:2747 [inline]
 user_path_at_empty+0xa1/0x100 fs/namei.c:2747
 user_path_at include/linux/namei.h:57 [inline]
 vfs_statx+0x142/0x390 fs/stat.c:203
 vfs_fstatat fs/stat.c:225 [inline]
 vfs_lstat include/linux/fs.h:3426 [inline]
 __do_sys_newlstat+0x91/0x110 fs/stat.c:380
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1354 [inline]
 free_pcp_prepare+0x312/0x7d0 mm/page_alloc.c:1405
 free_unref_page_prepare mm/page_alloc.c:3340 [inline]
 free_unref_page+0x19/0x690 mm/page_alloc.c:3419
 kvfree+0x42/0x50 mm/util.c:616
 netdev_freemem net/core/dev.c:10778 [inline]
 free_netdev+0x495/0x5b0 net/core/dev.c:10956
 rtl871x_load_fw_cb drivers/staging/rtl8712/hal_init.c:46 [inline]
 rtl871x_load_fw_cb.cold+0xf7/0x117 drivers/staging/rtl8712/hal_init.c:32
 request_firmware_work_func+0x12c/0x230 drivers/base/firmware_loader/main.c:1081
 process_one_work+0x98d/0x1630 kernel/workqueue.c:2276
 worker_thread+0x658/0x11f0 kernel/workqueue.c:2422
 kthread+0x3e5/0x4d0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

Memory state around the buggy address:
 ffff888038bbcd00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888038bbcd80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888038bbce00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                  ^
 ffff888038bbce80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888038bbcf00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
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syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
syzbot can test patches for this issue, for details see:
https://goo.gl/tpsmEJ#testing-patches

Re: [syzbot] KASAN: use-after-free Read in r871xu_dev_remove

[Pavel Skripkin]

[-- Attachment #1: Type: text/plain, Size: 1065 bytes --]

On Mon, 12 Jul 2021 20:14:24 -0700
syzbot <syzbot+5872a520e0ce0a7c7230@syzkaller.appspotmail.com> wrote:

> Hello,
> 
> syzbot found the following issue on:
> 
> HEAD commit:    92510a7f Add linux-next specific files for 20210709
> git tree:       linux-next
> console output:
> https://syzkaller.appspot.com/x/log.txt?x=16c50180300000 kernel
> config:  https://syzkaller.appspot.com/x/.config?x=505de2716f052686
> dashboard link:
> https://syzkaller.appspot.com/bug?extid=5872a520e0ce0a7c7230 syz
> repro:
> https://syzkaller.appspot.com/x/repro.syz?x=1639a73c300000 C
> reproducer:   https://syzkaller.appspot.com/x/repro.c?x=15fcd5e4300000
> 
> IMPORTANT: if you fix the issue, please add the following tag to the
> commit: Reported-by:
> syzbot+5872a520e0ce0a7c7230@syzkaller.appspotmail.com
> 

Hmm, bisection is wrong this time. It should be
e02a3b945816 ("staging: rtl8712: fix memory leak in rtl871x_load_fw_cb")

#syz test:
git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master


I guess, this should work


With regards,
Pavel Skripkin

[-- Attachment #2: 0001-staging-rtl8712-fix-UAF-in-r871xu_dev_remove.patch --]
[-- Type: text/x-patch, Size: 901 bytes --]

From 954ffa9067907a5f6d4d6d2b72a98b8773cac11e Mon Sep 17 00:00:00 2001
From: Pavel Skripkin <paskripkin@gmail.com>
Date: Tue, 13 Jul 2021 11:52:17 +0300
Subject: [PATCH] staging: rtl8712: fix UAF in r871xu_dev_remove

/* .... */

Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
---
 drivers/staging/rtl8712/hal_init.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/staging/rtl8712/hal_init.c b/drivers/staging/rtl8712/hal_init.c
index 22974277afa0..c06d31784cd4 100644
--- a/drivers/staging/rtl8712/hal_init.c
+++ b/drivers/staging/rtl8712/hal_init.c
@@ -43,6 +43,7 @@ static void rtl871x_load_fw_cb(const struct firmware *firmware, void *context)
 		r8712_free_drv_sw(adapter);
 		adapter->dvobj_deinit(adapter);
 		complete(&adapter->rtl8712_fw_ready);
+		shedule();				/* to not trigger UAF in wait_for_completion() */
 		free_netdev(adapter->pnetdev);
 		return;
 	}
-- 
2.32.0

Re: [syzbot] KASAN: use-after-free Read in r871xu_dev_remove

[Dongliang Mu]

On Tue, Jul 13, 2021 at 4:55 PM Pavel Skripkin <paskripkin@gmail.com> wrote:
>
> On Mon, 12 Jul 2021 20:14:24 -0700
> syzbot <syzbot+5872a520e0ce0a7c7230@syzkaller.appspotmail.com> wrote:
>
> > Hello,
> >
> > syzbot found the following issue on:
> >
> > HEAD commit:    92510a7f Add linux-next specific files for 20210709
> > git tree:       linux-next
> > console output:
> > https://syzkaller.appspot.com/x/log.txt?x=16c50180300000 kernel
> > config:  https://syzkaller.appspot.com/x/.config?x=505de2716f052686
> > dashboard link:
> > https://syzkaller.appspot.com/bug?extid=5872a520e0ce0a7c7230 syz
> > repro:
> > https://syzkaller.appspot.com/x/repro.syz?x=1639a73c300000 C
> > reproducer:   https://syzkaller.appspot.com/x/repro.c?x=15fcd5e4300000
> >
> > IMPORTANT: if you fix the issue, please add the following tag to the
> > commit: Reported-by:
> > syzbot+5872a520e0ce0a7c7230@syzkaller.appspotmail.com
> >
>
> Hmm, bisection is wrong this time. It should be
> e02a3b945816 ("staging: rtl8712: fix memory leak in rtl871x_load_fw_cb")

Hi Paval,

can you share more details about why the patch e02a3b945816 causes
this UAF problem?

>
> #syz test:
> git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
>
>
> I guess, this should work
>
>
> With regards,
> Pavel Skripkin
>
> --
> You received this message because you are subscribed to the Google Groups "syzkaller-bugs" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller-bugs+unsubscribe@googlegroups.com.
> To view this discussion on the web visit https://groups.google.com/d/msgid/syzkaller-bugs/20210713115546.34c99ea8%40gmail.com.

Re: [syzbot] KASAN: use-after-free Read in r871xu_dev_remove

[Pavel Skripkin]

[-- Attachment #1: Type: text/plain, Size: 2337 bytes --]

On Tue, 13 Jul 2021 17:04:28 +0800
Dongliang Mu <mudongliangabcd@gmail.com> wrote:

> On Tue, Jul 13, 2021 at 4:55 PM Pavel Skripkin <paskripkin@gmail.com>
> wrote:
> >
> > On Mon, 12 Jul 2021 20:14:24 -0700
> > syzbot <syzbot+5872a520e0ce0a7c7230@syzkaller.appspotmail.com>
> > wrote:
> >
> > > Hello,
> > >
> > > syzbot found the following issue on:
> > >
> > > HEAD commit:    92510a7f Add linux-next specific files for
> > > 20210709 git tree:       linux-next
> > > console output:
> > > https://syzkaller.appspot.com/x/log.txt?x=16c50180300000 kernel
> > > config:
> > > https://syzkaller.appspot.com/x/.config?x=505de2716f052686
> > > dashboard link:
> > > https://syzkaller.appspot.com/bug?extid=5872a520e0ce0a7c7230 syz
> > > repro: https://syzkaller.appspot.com/x/repro.syz?x=1639a73c300000
> > > C reproducer:
> > > https://syzkaller.appspot.com/x/repro.c?x=15fcd5e4300000
> > >
> > > IMPORTANT: if you fix the issue, please add the following tag to
> > > the commit: Reported-by:
> > > syzbot+5872a520e0ce0a7c7230@syzkaller.appspotmail.com
> > >
> >
> > Hmm, bisection is wrong this time. It should be
> > e02a3b945816 ("staging: rtl8712: fix memory leak in
> > rtl871x_load_fw_cb")
> 
> Hi Paval,
> 
    ^^^^^
    Pavel :)

> can you share more details about why the patch e02a3b945816 causes
> this UAF problem?
> 

I am not sure, but I think, that free_netdev() call rigth after
complete() can cause use-after-free bug in wait_for_completion() since
rtl8712_fw_ready is allocated as netdev private data.

I guess, schedule() call after complete() can help here.


BTW, I send wrong patch in previous email: typo in schedule() :)

#syz test:
git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master




> >
> > #syz test:
> > git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
> > master
> >
> >
> > I guess, this should work
> >
> >
> > With regards,
> > Pavel Skripkin
> >
> > --
> > You received this message because you are subscribed to the Google
> > Groups "syzkaller-bugs" group. To unsubscribe from this group and
> > stop receiving emails from it, send an email to
> > syzkaller-bugs+unsubscribe@googlegroups.com. To view this
> > discussion on the web visit
> > https://groups.google.com/d/msgid/syzkaller-bugs/20210713115546.34c99ea8%40gmail.com.




With regards,
Pavel Skripkin

[-- Attachment #2: 0001-staging-rtl8712-fix-UAF-in-r871xu_dev_remove.patch --]
[-- Type: text/x-patch, Size: 902 bytes --]

From 4c25accd0fc806687142aadeaa5b19805289ac74 Mon Sep 17 00:00:00 2001
From: Pavel Skripkin <paskripkin@gmail.com>
Date: Tue, 13 Jul 2021 11:52:17 +0300
Subject: [PATCH] staging: rtl8712: fix UAF in r871xu_dev_remove

/* .... */

Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
---
 drivers/staging/rtl8712/hal_init.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/staging/rtl8712/hal_init.c b/drivers/staging/rtl8712/hal_init.c
index 22974277afa0..e81c66cc8580 100644
--- a/drivers/staging/rtl8712/hal_init.c
+++ b/drivers/staging/rtl8712/hal_init.c
@@ -43,6 +43,7 @@ static void rtl871x_load_fw_cb(const struct firmware *firmware, void *context)
 		r8712_free_drv_sw(adapter);
 		adapter->dvobj_deinit(adapter);
 		complete(&adapter->rtl8712_fw_ready);
+		schedule();				/* to not trigger UAF in wait_for_completion() */
 		free_netdev(adapter->pnetdev);
 		return;
 	}
-- 
2.32.0

Re: [syzbot] KASAN: use-after-free Read in r871xu_dev_remove

[syzbot]

Hello,

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

drivers/staging/rtl8712/hal_init.c:46:3: error: implicit declaration of function 'shedule'; did you mean 'schedule'? [-Werror=implicit-function-declaration]


Tested on:

commit:         8f0df15b Add linux-next specific files for 20210713
git tree:       linux-next
dashboard link: https://syzkaller.appspot.com/bug?extid=5872a520e0ce0a7c7230
compiler:       
patch:          https://syzkaller.appspot.com/x/patch.diff?x=13a2c06c300000

Re: [syzbot] KASAN: use-after-free Read in r871xu_dev_remove

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KASAN: slab-out-of-bounds Read in r871xu_dev_remove

==================================================================
BUG: KASAN: slab-out-of-bounds in debug_spin_lock_before kernel/locking/spinlock_debug.c:83 [inline]
BUG: KASAN: slab-out-of-bounds in do_raw_spin_lock+0x262/0x2b0 kernel/locking/spinlock_debug.c:112
Read of size 4 at addr ffff88802f7ace14 by task kworker/0:0/5

CPU: 0 PID: 5 Comm: kworker/0:0 Tainted: G        W         5.14.0-rc1-next-20210713-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: usb_hub_wq hub_event
Call Trace:
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:105
 print_address_description.constprop.0.cold+0x6c/0x309 mm/kasan/report.c:233
 __kasan_report mm/kasan/report.c:419 [inline]
 kasan_report.cold+0x83/0xdf mm/kasan/report.c:436
 debug_spin_lock_before kernel/locking/spinlock_debug.c:83 [inline]
 do_raw_spin_lock+0x262/0x2b0 kernel/locking/spinlock_debug.c:112
 do_wait_for_common kernel/sched/completion.c:86 [inline]
 __wait_for_common kernel/sched/completion.c:106 [inline]
 wait_for_common kernel/sched/completion.c:117 [inline]
 wait_for_completion+0x181/0x280 kernel/sched/completion.c:138
 r871xu_dev_remove+0x80/0x320 drivers/staging/rtl8712/usb_intf.c:599
 usb_unbind_interface+0x1d8/0x8d0 drivers/usb/core/driver.c:458
 __device_release_driver+0x3bd/0x6f0 drivers/base/dd.c:1201
 device_release_driver_internal drivers/base/dd.c:1232 [inline]
 device_release_driver+0x26/0x40 drivers/base/dd.c:1255
 bus_remove_device+0x2eb/0x5a0 drivers/base/bus.c:529
 device_del+0x502/0xd40 drivers/base/core.c:3544
 usb_disable_device+0x35b/0x7b0 drivers/usb/core/message.c:1419
 usb_disconnect.cold+0x27a/0x78e drivers/usb/core/hub.c:2221
 hub_port_connect drivers/usb/core/hub.c:5151 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5440 [inline]
 port_event drivers/usb/core/hub.c:5586 [inline]
 hub_event+0x1c9c/0x4330 drivers/usb/core/hub.c:5668
 process_one_work+0x98d/0x1630 kernel/workqueue.c:2276
 worker_thread+0x658/0x11f0 kernel/workqueue.c:2422
 kthread+0x3e5/0x4d0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

Allocated by task 10657:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 ____kasan_kmalloc mm/kasan/common.c:513 [inline]
 ____kasan_kmalloc mm/kasan/common.c:472 [inline]
 __kasan_kmalloc+0x9b/0xd0 mm/kasan/common.c:522
 kmalloc include/linux/slab.h:596 [inline]
 tomoyo_realpath_from_path+0xc3/0x620 security/tomoyo/realpath.c:254
 tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
 tomoyo_path_number_perm+0x1d5/0x590 security/tomoyo/file.c:723
 security_file_ioctl+0x50/0xb0 security/security.c:1539
 __do_sys_ioctl fs/ioctl.c:1063 [inline]
 __se_sys_ioctl fs/ioctl.c:1055 [inline]
 __x64_sys_ioctl+0xb3/0x200 fs/ioctl.c:1055
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Freed by task 10657:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
 kasan_set_track+0x1c/0x30 mm/kasan/common.c:46
 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:360
 ____kasan_slab_free mm/kasan/common.c:366 [inline]
 ____kasan_slab_free mm/kasan/common.c:328 [inline]
 __kasan_slab_free+0xfb/0x130 mm/kasan/common.c:374
 kasan_slab_free include/linux/kasan.h:229 [inline]
 slab_free_hook mm/slub.c:1650 [inline]
 slab_free_freelist_hook+0xdf/0x240 mm/slub.c:1675
 slab_free mm/slub.c:3235 [inline]
 kfree+0xeb/0x650 mm/slub.c:4295
 tomoyo_realpath_from_path+0x191/0x620 security/tomoyo/realpath.c:291
 tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
 tomoyo_path_number_perm+0x1d5/0x590 security/tomoyo/file.c:723
 security_file_ioctl+0x50/0xb0 security/security.c:1539
 __do_sys_ioctl fs/ioctl.c:1063 [inline]
 __se_sys_ioctl fs/ioctl.c:1055 [inline]
 __x64_sys_ioctl+0xb3/0x200 fs/ioctl.c:1055
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

The buggy address belongs to the object at ffff88802f7ac000
 which belongs to the cache kmalloc-4k of size 4096
The buggy address is located 3604 bytes inside of
 4096-byte region [ffff88802f7ac000, ffff88802f7ad000)
The buggy address belongs to the page:
page:ffffea0000bdea00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2f7a8
head:ffffea0000bdea00 order:3 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 0000000000000000 dead000000000122 ffff888010842140
raw: 0000000000000000 0000000000040004 00000001ffffffff 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 59, ts 93061328154, free_ts 93052725619
 prep_new_page mm/page_alloc.c:2433 [inline]
 get_page_from_freelist+0xa72/0x2f80 mm/page_alloc.c:4166
 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5374
 alloc_pages+0x18c/0x2a0 mm/mempolicy.c:2244
 alloc_slab_page mm/slub.c:1713 [inline]
 allocate_slab+0x32b/0x4c0 mm/slub.c:1853
 new_slab mm/slub.c:1916 [inline]
 new_slab_objects mm/slub.c:2662 [inline]
 ___slab_alloc+0x4ba/0x820 mm/slub.c:2825
 __slab_alloc.constprop.0+0xa7/0xf0 mm/slub.c:2865
 slab_alloc_node mm/slub.c:2947 [inline]
 slab_alloc mm/slub.c:2989 [inline]
 kmem_cache_alloc_trace+0x30f/0x3c0 mm/slub.c:3006
 kmalloc include/linux/slab.h:591 [inline]
 kzalloc include/linux/slab.h:721 [inline]
 kobject_uevent_env+0x240/0x1650 lib/kobject_uevent.c:524
 driver_bound+0x1a8/0x300 drivers/base/dd.c:401
 really_probe+0x3d8/0xcd0 drivers/base/dd.c:643
 __driver_probe_device+0x338/0x4d0 drivers/base/dd.c:747
 driver_probe_device+0x4c/0x1a0 drivers/base/dd.c:777
 __device_attach_driver+0x20b/0x2f0 drivers/base/dd.c:894
 bus_for_each_drv+0x15f/0x1e0 drivers/base/bus.c:427
 __device_attach+0x228/0x4a0 drivers/base/dd.c:965
 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:487
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1343 [inline]
 free_pcp_prepare+0x312/0x7d0 mm/page_alloc.c:1394
 free_unref_page_prepare mm/page_alloc.c:3329 [inline]
 free_unref_page+0x19/0x690 mm/page_alloc.c:3408
 kvfree+0x42/0x50 mm/util.c:616
 netdev_freemem net/core/dev.c:10780 [inline]
 free_netdev+0x495/0x5b0 net/core/dev.c:10958
 rtl871x_load_fw_cb drivers/staging/rtl8712/hal_init.c:47 [inline]
 rtl871x_load_fw_cb.cold+0x100/0x120 drivers/staging/rtl8712/hal_init.c:32
 request_firmware_work_func+0x12c/0x230 drivers/base/firmware_loader/main.c:1081
 process_one_work+0x98d/0x1630 kernel/workqueue.c:2276
 worker_thread+0x658/0x11f0 kernel/workqueue.c:2422
 kthread+0x3e5/0x4d0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

Memory state around the buggy address:
 ffff88802f7acd00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88802f7acd80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88802f7ace00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                         ^
 ffff88802f7ace80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88802f7acf00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


Tested on:

commit:         8f0df15b Add linux-next specific files for 20210713
git tree:       linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=12ef886c300000
kernel config:  https://syzkaller.appspot.com/x/.config?x=5ef73f190e4b0b9a
dashboard link: https://syzkaller.appspot.com/bug?extid=5872a520e0ce0a7c7230
compiler:       
patch:          https://syzkaller.appspot.com/x/patch.diff?x=164561d2300000

Re: [syzbot] KASAN: use-after-free Read in r871xu_dev_remove

[Pavel Skripkin]

[-- Attachment #1: Type: text/plain, Size: 1234 bytes --]

On Mon, 12 Jul 2021 20:14:24 -0700
syzbot <syzbot+5872a520e0ce0a7c7230@syzkaller.appspotmail.com> wrote:

> Hello,
> 
> syzbot found the following issue on:
> 
> HEAD commit:    92510a7f Add linux-next specific files for 20210709
> git tree:       linux-next
> console output:
> https://syzkaller.appspot.com/x/log.txt?x=16c50180300000 kernel
> config:  https://syzkaller.appspot.com/x/.config?x=505de2716f052686
> dashboard link:
> https://syzkaller.appspot.com/bug?extid=5872a520e0ce0a7c7230 syz
> repro:
> https://syzkaller.appspot.com/x/repro.syz?x=1639a73c300000 C
> reproducer:   https://syzkaller.appspot.com/x/repro.c?x=15fcd5e4300000
> 
> IMPORTANT: if you fix the issue, please add the following tag to the
> commit: Reported-by:
> syzbot+5872a520e0ce0a7c7230@syzkaller.appspotmail.com
> 
> usb 1-1: USB disconnect, device number 14
> ==================================================================
> BUG: KASAN: use-after-free in __lock_acquire+0x3d86/0x54a0
> kernel/locking/lockdep.c:4885 Read of size 8 at addr ffff888038bbce28
> by task kworker/1:2/4393
> 

And let's test it with this repro as well.


#syz test
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master


With regards,
Pavel Skripkin

[-- Attachment #2: 2patches.patch --]
[-- Type: text/x-patch, Size: 7388 bytes --]

diff --git a/drivers/staging/rtl8712/hal_init.c b/drivers/staging/rtl8712/hal_init.c
index 22974277afa0..4eff3fdecdb8 100644
--- a/drivers/staging/rtl8712/hal_init.c
+++ b/drivers/staging/rtl8712/hal_init.c
@@ -29,21 +29,31 @@
 #define FWBUFF_ALIGN_SZ 512
 #define MAX_DUMP_FWSZ (48 * 1024)
 
+static void rtl871x_load_fw_fail(struct _adapter *adapter)
+{
+	struct usb_device *udev = adapter->dvobjpriv.pusbdev;
+	struct device *dev = &udev->dev;
+	struct device *parent = dev->parent;
+
+	complete(&adapter->rtl8712_fw_ready);
+
+	dev_err(&udev->dev, "r8712u: Firmware request failed\n");
+
+	if (parent)
+		device_lock(parent);
+
+	device_release_driver(dev);
+
+	if (parent)
+		device_unlock(parent);
+}
+
 static void rtl871x_load_fw_cb(const struct firmware *firmware, void *context)
 {
 	struct _adapter *adapter = context;
 
 	if (!firmware) {
-		struct usb_device *udev = adapter->dvobjpriv.pusbdev;
-		struct usb_interface *usb_intf = adapter->pusb_intf;
-
-		dev_err(&udev->dev, "r8712u: Firmware request failed\n");
-		usb_put_dev(udev);
-		usb_set_intfdata(usb_intf, NULL);
-		r8712_free_drv_sw(adapter);
-		adapter->dvobj_deinit(adapter);
-		complete(&adapter->rtl8712_fw_ready);
-		free_netdev(adapter->pnetdev);
+		rtl871x_load_fw_fail(adapter);
 		return;
 	}
 	adapter->fw = firmware;
diff --git a/drivers/staging/rtl8712/rtl8712_led.c b/drivers/staging/rtl8712/rtl8712_led.c
index 5901026949f2..d5fc9026b036 100644
--- a/drivers/staging/rtl8712/rtl8712_led.c
+++ b/drivers/staging/rtl8712/rtl8712_led.c
@@ -1820,3 +1820,11 @@ void LedControl871x(struct _adapter *padapter, enum LED_CTL_MODE LedAction)
 		break;
 	}
 }
+
+void r8712_flush_led_works(struct _adapter *padapter)
+{
+	struct led_priv *pledpriv = &padapter->ledpriv;
+
+	flush_work(&pledpriv->SwLed0.BlinkWorkItem);
+	flush_work(&pledpriv->SwLed1.BlinkWorkItem);
+}
diff --git a/drivers/staging/rtl8712/rtl871x_led.h b/drivers/staging/rtl8712/rtl871x_led.h
index ee19c873cf01..2f0768132ad8 100644
--- a/drivers/staging/rtl8712/rtl871x_led.h
+++ b/drivers/staging/rtl8712/rtl871x_led.h
@@ -112,6 +112,7 @@ struct led_priv {
 void r8712_InitSwLeds(struct _adapter *padapter);
 void r8712_DeInitSwLeds(struct _adapter *padapter);
 void LedControl871x(struct _adapter *padapter, enum LED_CTL_MODE LedAction);
+void r8712_flush_led_works(struct _adapter *padapter);
 
 #endif
 
diff --git a/drivers/staging/rtl8712/rtl871x_pwrctrl.c b/drivers/staging/rtl8712/rtl871x_pwrctrl.c
index 23cff43437e2..cd6d9ff0bebc 100644
--- a/drivers/staging/rtl8712/rtl871x_pwrctrl.c
+++ b/drivers/staging/rtl8712/rtl871x_pwrctrl.c
@@ -224,3 +224,11 @@ void r8712_unregister_cmd_alive(struct _adapter *padapter)
 	}
 	mutex_unlock(&pwrctrl->mutex_lock);
 }
+
+void r8712_flush_rwctrl_works(struct _adapter *padapter)
+{
+	struct pwrctrl_priv *pwrctrl = &padapter->pwrctrlpriv;
+
+	flush_work(&pwrctrl->SetPSModeWorkItem);
+	flush_work(&pwrctrl->rpwm_workitem);
+}
diff --git a/drivers/staging/rtl8712/rtl871x_pwrctrl.h b/drivers/staging/rtl8712/rtl871x_pwrctrl.h
index bf6623cfaf27..b35b9c7920eb 100644
--- a/drivers/staging/rtl8712/rtl871x_pwrctrl.h
+++ b/drivers/staging/rtl8712/rtl871x_pwrctrl.h
@@ -108,5 +108,6 @@ void r8712_cpwm_int_hdl(struct _adapter *padapter,
 void r8712_set_ps_mode(struct _adapter *padapter, uint ps_mode,
 			uint smart_ps);
 void r8712_set_rpwm(struct _adapter *padapter, u8 val8);
+void r8712_flush_rwctrl_works(struct _adapter *padapter);
 
 #endif  /* __RTL871X_PWRCTRL_H_ */
diff --git a/drivers/staging/rtl8712/usb_intf.c b/drivers/staging/rtl8712/usb_intf.c
index 2434b13c8b12..505ebeb643dc 100644
--- a/drivers/staging/rtl8712/usb_intf.c
+++ b/drivers/staging/rtl8712/usb_intf.c
@@ -591,35 +591,30 @@ static void r871xu_dev_remove(struct usb_interface *pusb_intf)
 {
 	struct net_device *pnetdev = usb_get_intfdata(pusb_intf);
 	struct usb_device *udev = interface_to_usbdev(pusb_intf);
+	struct _adapter *padapter = netdev_priv(pnetdev);
+
+	/* never exit with a firmware callback pending */
+	wait_for_completion(&padapter->rtl8712_fw_ready);
+	usb_set_intfdata(pusb_intf, NULL);
+	release_firmware(padapter->fw);
+	if (drvpriv.drv_registered)
+		padapter->surprise_removed = true;
+	if (pnetdev->reg_state != NETREG_UNINITIALIZED)
+		unregister_netdev(pnetdev); /* will call netdev_close() */
+	r8712_flush_rwctrl_works(padapter);
+	r8712_flush_led_works(padapter);
+	udelay(1);
+	/* Stop driver mlme relation timer */
+	r8712_stop_drv_timers(padapter);
+	r871x_dev_unload(padapter);
+	r8712_free_drv_sw(padapter);
+	free_netdev(pnetdev);
+
+	/* decrease the reference count of the usb device structure
+	 * when disconnect
+	 */
+	usb_put_dev(udev);
 
-	if (pnetdev) {
-		struct _adapter *padapter = netdev_priv(pnetdev);
-
-		/* never exit with a firmware callback pending */
-		wait_for_completion(&padapter->rtl8712_fw_ready);
-		pnetdev = usb_get_intfdata(pusb_intf);
-		usb_set_intfdata(pusb_intf, NULL);
-		if (!pnetdev)
-			goto firmware_load_fail;
-		release_firmware(padapter->fw);
-		if (drvpriv.drv_registered)
-			padapter->surprise_removed = true;
-		if (pnetdev->reg_state != NETREG_UNINITIALIZED)
-			unregister_netdev(pnetdev); /* will call netdev_close() */
-		flush_scheduled_work();
-		udelay(1);
-		/* Stop driver mlme relation timer */
-		r8712_stop_drv_timers(padapter);
-		r871x_dev_unload(padapter);
-		r8712_free_drv_sw(padapter);
-		free_netdev(pnetdev);
-
-		/* decrease the reference count of the usb device structure
-		 * when disconnect
-		 */
-		usb_put_dev(udev);
-	}
-firmware_load_fail:
 	/* If we didn't unplug usb dongle and remove/insert module, driver
 	 * fails on sitesurvey for the first time when device is up.
 	 * Reset usb port for sitesurvey fail issue.
diff --git a/net/bluetooth/hci_sock.c b/net/bluetooth/hci_sock.c
index b04a5a02ecf3..786a06a232fd 100644
--- a/net/bluetooth/hci_sock.c
+++ b/net/bluetooth/hci_sock.c
@@ -760,10 +760,18 @@ void hci_sock_dev_event(struct hci_dev *hdev, int event)
 		struct sock *sk;
 
 		/* Detach sockets from device */
+restart:
 		read_lock(&hci_sk_list.lock);
 		sk_for_each(sk, &hci_sk_list.head) {
+			/* This sock_hold(sk) is safe, for bt_sock_unlink(sk)
+			 * is not called yet.
+			 */
+			sock_hold(sk);
+			read_unlock(&hci_sk_list.lock);
 			lock_sock(sk);
-			if (hci_pi(sk)->hdev == hdev) {
+			write_lock(&hci_sk_list.lock);
+			/* Check that bt_sock_unlink(sk) is not called yet. */
+			if (sk_hashed(sk) && hci_pi(sk)->hdev == hdev) {
 				hci_pi(sk)->hdev = NULL;
 				sk->sk_err = EPIPE;
 				sk->sk_state = BT_OPEN;
@@ -771,7 +779,27 @@ void hci_sock_dev_event(struct hci_dev *hdev, int event)
 
 				hci_dev_put(hdev);
 			}
+			write_unlock(&hci_sk_list.lock);
 			release_sock(sk);
+			read_lock(&hci_sk_list.lock);
+			/* If bt_sock_unlink(sk) is not called yet, we can
+			 * continue iteration. We can use __sock_put(sk) here
+			 * because hci_sock_release() will call sock_put(sk)
+			 * after bt_sock_unlink(sk).
+			 */
+			if (sk_hashed(sk)) {
+				__sock_put(sk);
+				continue;
+			}
+			/* Otherwise, we need to restart iteration, for the
+			 * next socket pointed by sk->next might be already
+			 * gone. We can't use __sock_put(sk) here because
+			 * hci_sock_release() might have already called
+			 * sock_put(sk) after bt_sock_unlink(sk).
+			 */
+			read_unlock(&hci_sk_list.lock);
+			sock_put(sk);
+			goto restart;
 		}
 		read_unlock(&hci_sk_list.lock);
 	}

Re: [syzbot] KASAN: use-after-free Read in r871xu_dev_remove

[syzbot]

Hello,

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

Reported-and-tested-by: syzbot+5872a520e0ce0a7c7230@syzkaller.appspotmail.com

Tested on:

commit:         8cae8cd8 seq_file: disallow extremely large seq buffer..
git tree:       upstream
kernel config:  https://syzkaller.appspot.com/x/.config?x=f7dfeb6dfc05ea19
dashboard link: https://syzkaller.appspot.com/bug?extid=5872a520e0ce0a7c7230
compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.1
patch:          https://syzkaller.appspot.com/x/patch.diff?x=11291aa2300000

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