[BUG] staging: r8188eu: KASAN: slab-out-of-bounds in rtw_cmd_thread

[BUG] staging: r8188eu: KASAN: slab-out-of-bounds in rtw_cmd_thread

[Michael Straube]

Hi,

It looks like
commit 0afaa121813e ("staging: r8188eu: use in-kernel ieee channel")
intoduced a. See KASAN output below.

That commit replaced the use of struct rtw_ieee80211_channel with struct
ieee80211_channel.

There are several calls to memcpy that used sizeof(struct 
rtw_ieee80211_channel)
and now use sizeof(struct ieee80211_channel) but the sizes of these two 
structures are not equal.

regards,
Michael

dmesg:

  ==================================================================
[  422.214237] BUG: KASAN: slab-out-of-bounds in 
rtw_cmd_thread+0x1e8/0x430 [r8188eu]
[  422.214277] Write of size 3600 at addr ffff8881e149d200 by task 
RTW_CMD_THREAD/2563

[  422.214289] CPU: 11 PID: 2563 Comm: RTW_CMD_THREAD Tainted: G 
C OE     5.18.0-rc2-staging+ #47 94e3ca73bebf5b7fec506721475e4fff2a023bb9
[  422.214301] Hardware name: Gigabyte Technology Co., Ltd. B550M 
S2H/B550M S2H, BIOS F15a 02/16/2022
[  422.214309] Call Trace:
[  422.214313]  <TASK>
[  422.214317]  dump_stack_lvl+0x45/0x5b
[  422.214327]  print_report.cold+0x5e/0x5dc
[  422.214335]  ? kasan_set_track+0x21/0x30
[  422.214342]  ? kasan_set_free_info+0x20/0x40
[  422.214349]  ? rtw_cmd_thread+0x1e8/0x430 [r8188eu 
91924fe1575bf49b9b37985ffde2c585d847446d]
[  422.214386]  kasan_report+0xab/0x120
[  422.214394]  ? rtw_cmd_thread+0x1e8/0x430 [r8188eu 
91924fe1575bf49b9b37985ffde2c585d847446d]
[  422.214430]  kasan_check_range+0xf6/0x1d0
[  422.214436]  memcpy+0x39/0x60
[  422.214442]  rtw_cmd_thread+0x1e8/0x430 [r8188eu 
91924fe1575bf49b9b37985ffde2c585d847446d]
[  422.214479]  ? rtw_setassocsta_cmdrsp_callback+0xd0/0xd0 [r8188eu 
91924fe1575bf49b9b37985ffde2c585d847446d]
[  422.214516]  kthread+0x15d/0x190
[  422.214523]  ? kthread_complete_and_exit+0x20/0x20
[  422.214531]  ret_from_fork+0x22/0x30
[  422.214540]  </TASK>

[  422.214546] Allocated by task 2522:
[  422.214551]  kasan_save_stack+0x1e/0x40
[  422.214555]  __kasan_kmalloc+0xa9/0xe0
[  422.214559]  rtw_init_cmd_priv+0xd6/0x1b0 [r8188eu]
[  422.214589]  rtw_init_drv_sw+0x21/0x370 [r8188eu]
[  422.214619]  rtw_drv_init+0x3a6/0x4f0 [r8188eu]
[  422.214649]  usb_probe_interface+0x155/0x340 [usbcore]
[  422.214705]  really_probe.part.0+0x11f/0x320
[  422.214709]  __driver_probe_device+0xe0/0x180
[  422.214712]  driver_probe_device+0x4d/0x170
[  422.214715]  __driver_attach+0x110/0x250
[  422.214718]  bus_for_each_dev+0xe7/0x140
[  422.214721]  bus_add_driver+0x25a/0x2b0
[  422.214723]  driver_register+0x10f/0x190
[  422.214726]  usb_register_driver+0x10e/0x1e0 [usbcore]
[  422.214780]  do_one_initcall+0x8a/0x2a0
[  422.214784]  do_init_module+0xe4/0x3b0
[  422.214787]  load_module+0x41c4/0x4650
[  422.214789]  __do_sys_finit_module+0x111/0x190
[  422.214791]  do_syscall_64+0x5c/0x80
[  422.214795]  entry_SYSCALL_64_after_hwframe+0x44/0xae

[  422.214802] Last potentially related work creation:
[  422.214807]  kasan_save_stack+0x1e/0x40
[  422.214810]  __kasan_record_aux_stack+0xb1/0xc0
[  422.214813]  call_rcu+0xb5/0xfc0
[  422.214817]  netlink_release+0x791/0xa40
[  422.214820]  __sock_release+0x72/0x120
[  422.214824]  sock_close+0x11/0x20
[  422.214828]  __fput+0x10c/0x400
[  422.214831]  task_work_run+0x8b/0xc0
[  422.214834]  do_exit+0x5a4/0x10e0
[  422.214837]  do_group_exit+0x58/0x100
[  422.214840]  __x64_sys_exit_group+0x28/0x30
[  422.214843]  do_syscall_64+0x5c/0x80
[  422.214846]  entry_SYSCALL_64_after_hwframe+0x44/0xae

[  422.214852] The buggy address belongs to the object at ffff8881e149d000
                 which belongs to the cache kmalloc-2k of size 2048
[  422.214862] The buggy address is located 512 bytes inside of
                 2048-byte region [ffff8881e149d000, ffff8881e149d800)

[  422.214874] The buggy address belongs to the physical page:
[  422.214879] page:000000003f187866 refcount:1 mapcount:0 
mapping:0000000000000000 index:0x0 pfn:0x1e1498
[  422.214883] head:000000003f187866 order:3 compound_mapcount:0 
compound_pincount:0
[  422.214885] flags: 
0x17ffffc0010200(slab|head|node=0|zone=2|lastcpupid=0x1fffff)
[  422.214891] raw: 0017ffffc0010200 ffffea0004f1ca00 dead000000000002 
ffff888100042f00
[  422.214894] raw: 0000000000000000 0000000000080008 00000001ffffffff 
0000000000000000
[  422.214896] page dumped because: kasan: bad access detected

[  422.214900] Memory state around the buggy address:
[  422.214905]  ffff8881e149d500: 00 00 00 00 00 00 00 00 00 00 00 00 00 
00 00 00
[  422.214914]  ffff8881e149d580: 00 00 00 00 00 00 00 00 00 00 00 00 00 
00 00 00
[  422.214921] >ffff8881e149d600: fc fc fc fc fc fc fc fc fc fc fc fc fc 
fc fc fc
[  422.214927]                    ^
[  422.214932]  ffff8881e149d680: fc fc fc fc fc fc fc fc fc fc fc fc fc 
fc fc fc
[  422.214939]  ffff8881e149d700: fc fc fc fc fc fc fc fc fc fc fc fc fc 
fc fc fc
[  422.214946] 
==================================================================

Re: [BUG] staging: r8188eu: KASAN: slab-out-of-bounds in rtw_cmd_thread

[Solomon Tan]

On Sun, Apr 24, 2022 at 12:00:12PM +0200, Michael Straube wrote:
> Hi,
> 
> It looks like
> commit 0afaa121813e ("staging: r8188eu: use in-kernel ieee channel")
> intoduced a. See KASAN output below.
> 
> That commit replaced the use of struct rtw_ieee80211_channel with struct
> ieee80211_channel.
> 
> There are several calls to memcpy that used sizeof(struct
> rtw_ieee80211_channel)
> and now use sizeof(struct ieee80211_channel) but the sizes of these two
> structures are not equal.
> 

Oh no. When does this issue get triggered?

> regards,
> Michael
> 
> dmesg:
> 
>  ==================================================================
> [  422.214237] BUG: KASAN: slab-out-of-bounds in rtw_cmd_thread+0x1e8/0x430
> [r8188eu]
> [  422.214277] Write of size 3600 at addr ffff8881e149d200 by task
> RTW_CMD_THREAD/2563
> 
> [  422.214289] CPU: 11 PID: 2563 Comm: RTW_CMD_THREAD Tainted: G C OE
> 5.18.0-rc2-staging+ #47 94e3ca73bebf5b7fec506721475e4fff2a023bb9
> [  422.214301] Hardware name: Gigabyte Technology Co., Ltd. B550M S2H/B550M
> S2H, BIOS F15a 02/16/2022
> [  422.214309] Call Trace:
> [  422.214313]  <TASK>
> [  422.214317]  dump_stack_lvl+0x45/0x5b
> [  422.214327]  print_report.cold+0x5e/0x5dc
> [  422.214335]  ? kasan_set_track+0x21/0x30
> [  422.214342]  ? kasan_set_free_info+0x20/0x40
> [  422.214349]  ? rtw_cmd_thread+0x1e8/0x430 [r8188eu
> 91924fe1575bf49b9b37985ffde2c585d847446d]
> [  422.214386]  kasan_report+0xab/0x120
> [  422.214394]  ? rtw_cmd_thread+0x1e8/0x430 [r8188eu
> 91924fe1575bf49b9b37985ffde2c585d847446d]
> [  422.214430]  kasan_check_range+0xf6/0x1d0
> [  422.214436]  memcpy+0x39/0x60
> [  422.214442]  rtw_cmd_thread+0x1e8/0x430 [r8188eu
> 91924fe1575bf49b9b37985ffde2c585d847446d]
> [  422.214479]  ? rtw_setassocsta_cmdrsp_callback+0xd0/0xd0 [r8188eu
> 91924fe1575bf49b9b37985ffde2c585d847446d]
> [  422.214516]  kthread+0x15d/0x190
> [  422.214523]  ? kthread_complete_and_exit+0x20/0x20
> [  422.214531]  ret_from_fork+0x22/0x30
> [  422.214540]  </TASK>

Sorry, I am not familiar with KASAN. How should I interpret this output?
I see the paragraph above has references to rtw_cmd_thread. I assume
that is its way of indicating that rtw_cmd_thread is the cause of the
problem, but the one below refers to other functions. I'm not sure where
I should start looking. I would start looking at `rtw_sitesurvey_cmd` and
`rtw_scan_ch_decision`, which call the memcpy on the
rtw_ieee80211_channel structure, but they are not on the call trace.

> 
> [  422.214546] Allocated by task 2522:
> [  422.214551]  kasan_save_stack+0x1e/0x40
> [  422.214555]  __kasan_kmalloc+0xa9/0xe0
> [  422.214559]  rtw_init_cmd_priv+0xd6/0x1b0 [r8188eu]
> [  422.214589]  rtw_init_drv_sw+0x21/0x370 [r8188eu]
> [  422.214619]  rtw_drv_init+0x3a6/0x4f0 [r8188eu]
> [  422.214649]  usb_probe_interface+0x155/0x340 [usbcore]
> [  422.214705]  really_probe.part.0+0x11f/0x320
> [  422.214709]  __driver_probe_device+0xe0/0x180
> [  422.214712]  driver_probe_device+0x4d/0x170
> [  422.214715]  __driver_attach+0x110/0x250
> [  422.214718]  bus_for_each_dev+0xe7/0x140
> [  422.214721]  bus_add_driver+0x25a/0x2b0
> [  422.214723]  driver_register+0x10f/0x190
> [  422.214726]  usb_register_driver+0x10e/0x1e0 [usbcore]
> [  422.214780]  do_one_initcall+0x8a/0x2a0
> [  422.214784]  do_init_module+0xe4/0x3b0
> [  422.214787]  load_module+0x41c4/0x4650
> [  422.214789]  __do_sys_finit_module+0x111/0x190
> [  422.214791]  do_syscall_64+0x5c/0x80
> [  422.214795]  entry_SYSCALL_64_after_hwframe+0x44/0xae
> 
> [  422.214802] Last potentially related work creation:
> [  422.214807]  kasan_save_stack+0x1e/0x40
> [  422.214810]  __kasan_record_aux_stack+0xb1/0xc0
> [  422.214813]  call_rcu+0xb5/0xfc0
> [  422.214817]  netlink_release+0x791/0xa40
> [  422.214820]  __sock_release+0x72/0x120
> [  422.214824]  sock_close+0x11/0x20
> [  422.214828]  __fput+0x10c/0x400
> [  422.214831]  task_work_run+0x8b/0xc0
> [  422.214834]  do_exit+0x5a4/0x10e0
> [  422.214837]  do_group_exit+0x58/0x100
> [  422.214840]  __x64_sys_exit_group+0x28/0x30
> [  422.214843]  do_syscall_64+0x5c/0x80
> [  422.214846]  entry_SYSCALL_64_after_hwframe+0x44/0xae
> 
> [  422.214852] The buggy address belongs to the object at ffff8881e149d000
>                 which belongs to the cache kmalloc-2k of size 2048
> [  422.214862] The buggy address is located 512 bytes inside of
>                 2048-byte region [ffff8881e149d000, ffff8881e149d800)
> 
> [  422.214874] The buggy address belongs to the physical page:
> [  422.214879] page:000000003f187866 refcount:1 mapcount:0
> mapping:0000000000000000 index:0x0 pfn:0x1e1498
> [  422.214883] head:000000003f187866 order:3 compound_mapcount:0
> compound_pincount:0
> [  422.214885] flags:
> 0x17ffffc0010200(slab|head|node=0|zone=2|lastcpupid=0x1fffff)
> [  422.214891] raw: 0017ffffc0010200 ffffea0004f1ca00 dead000000000002
> ffff888100042f00
> [  422.214894] raw: 0000000000000000 0000000000080008 00000001ffffffff
> 0000000000000000
> [  422.214896] page dumped because: kasan: bad access detected
> 
> [  422.214900] Memory state around the buggy address:
> [  422.214905]  ffff8881e149d500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> 00 00
> [  422.214914]  ffff8881e149d580: 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> 00 00
> [  422.214921] >ffff8881e149d600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc
> fc fc
> [  422.214927]                    ^
> [  422.214932]  ffff8881e149d680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc
> fc fc
> [  422.214939]  ffff8881e149d700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc
> fc fc
> [  422.214946]
> ==================================================================

Re: [BUG] staging: r8188eu: KASAN: slab-out-of-bounds in rtw_cmd_thread

[Pavel Skripkin]

Hi Solomon,

On 4/24/22 15:11, Solomon Tan wrote:
> On Sun, Apr 24, 2022 at 12:00:12PM +0200, Michael Straube wrote:
>> Hi,
>> 
>> It looks like
>> commit 0afaa121813e ("staging: r8188eu: use in-kernel ieee channel")
>> intoduced a. See KASAN output below.
>> 
>> That commit replaced the use of struct rtw_ieee80211_channel with struct
>> ieee80211_channel.
>> 
>> There are several calls to memcpy that used sizeof(struct
>> rtw_ieee80211_channel)
>> and now use sizeof(struct ieee80211_channel) but the sizes of these two
>> structures are not equal.
>> 
> 
> Oh no. When does this issue get triggered?
> 
>> regards,
>> Michael
>> 
>> dmesg:
>> 
>>  ==================================================================
>> [  422.214237] BUG: KASAN: slab-out-of-bounds in rtw_cmd_thread+0x1e8/0x430
>> [r8188eu]
>> [  422.214277] Write of size 3600 at addr ffff8881e149d200 by task
>> RTW_CMD_THREAD/2563
>> 
>> [  422.214289] CPU: 11 PID: 2563 Comm: RTW_CMD_THREAD Tainted: G C OE
>> 5.18.0-rc2-staging+ #47 94e3ca73bebf5b7fec506721475e4fff2a023bb9
>> [  422.214301] Hardware name: Gigabyte Technology Co., Ltd. B550M S2H/B550M
>> S2H, BIOS F15a 02/16/2022
>> [  422.214309] Call Trace:
>> [  422.214313]  <TASK>
>> [  422.214317]  dump_stack_lvl+0x45/0x5b
>> [  422.214327]  print_report.cold+0x5e/0x5dc
>> [  422.214335]  ? kasan_set_track+0x21/0x30
>> [  422.214342]  ? kasan_set_free_info+0x20/0x40
>> [  422.214349]  ? rtw_cmd_thread+0x1e8/0x430 [r8188eu
>> 91924fe1575bf49b9b37985ffde2c585d847446d]
>> [  422.214386]  kasan_report+0xab/0x120
>> [  422.214394]  ? rtw_cmd_thread+0x1e8/0x430 [r8188eu
>> 91924fe1575bf49b9b37985ffde2c585d847446d]
>> [  422.214430]  kasan_check_range+0xf6/0x1d0
>> [  422.214436]  memcpy+0x39/0x60
>> [  422.214442]  rtw_cmd_thread+0x1e8/0x430 [r8188eu
>> 91924fe1575bf49b9b37985ffde2c585d847446d]
>> [  422.214479]  ? rtw_setassocsta_cmdrsp_callback+0xd0/0xd0 [r8188eu
>> 91924fe1575bf49b9b37985ffde2c585d847446d]
>> [  422.214516]  kthread+0x15d/0x190
>> [  422.214523]  ? kthread_complete_and_exit+0x20/0x20
>> [  422.214531]  ret_from_fork+0x22/0x30
>> [  422.214540]  </TASK>
> 
> Sorry, I am not familiar with KASAN. How should I interpret this output?
> I see the paragraph above has references to rtw_cmd_thread. I assume
> that is its way of indicating that rtw_cmd_thread is the cause of the
> problem, but the one below refers to other functions. I'm not sure where
> I should start looking. I would start looking at `rtw_sitesurvey_cmd` and
> `rtw_scan_ch_decision`, which call the memcpy on the
> rtw_ieee80211_channel structure, but they are not on the call trace.
> 

drivers/staging/r8188eu/core/rtw_cmd.c:276: memcpy() call.

As Michael said the sizes of structures do not mach and the memcpy 
writes below allocated buffer.



With regards,
Pavel Skripkin

Re: [BUG] staging: r8188eu: KASAN: slab-out-of-bounds in rtw_cmd_thread

[Solomon Tan]

> > > It looks like
> > > commit 0afaa121813e ("staging: r8188eu: use in-kernel ieee channel")
> > > intoduced a. See KASAN output below.
> > > 
> > > That commit replaced the use of struct rtw_ieee80211_channel with struct
> > > ieee80211_channel.
> > > 
> > > There are several calls to memcpy that used sizeof(struct
> > > rtw_ieee80211_channel)
> > > and now use sizeof(struct ieee80211_channel) but the sizes of these two
> > > structures are not equal.
> > > 
> 
> drivers/staging/r8188eu/core/rtw_cmd.c:276: memcpy() call.
> 
> As Michael said the sizes of structures do not mach and the memcpy writes
> below allocated buffer.
> 
Thanks Pavel.

Hi Michael, I could not find the cause of this issue, and I am afraid I
might break even more stuff if I attempt to fix it, so I have submitted
a new patch to revert my changes. Sorry for the inconvenience.

Cheers,
Solomon

Re: [BUG] staging: r8188eu: KASAN: slab-out-of-bounds in rtw_cmd_thread

[Dan Carpenter]

On Sun, Apr 24, 2022 at 06:06:32PM +0300, Pavel Skripkin wrote:
> Hi Solomon,
> 
> On 4/24/22 15:11, Solomon Tan wrote:
> > On Sun, Apr 24, 2022 at 12:00:12PM +0200, Michael Straube wrote:
> > > Hi,
> > > 
> > > It looks like
> > > commit 0afaa121813e ("staging: r8188eu: use in-kernel ieee channel")
> > > intoduced a. See KASAN output below.
> > > 
> > > That commit replaced the use of struct rtw_ieee80211_channel with struct
> > > ieee80211_channel.
> > > 
> > > There are several calls to memcpy that used sizeof(struct
> > > rtw_ieee80211_channel)
> > > and now use sizeof(struct ieee80211_channel) but the sizes of these two
> > > structures are not equal.
> > > 
> > 
> > Oh no. When does this issue get triggered?
> > 
> > > regards,
> > > Michael
> > > 
> > > dmesg:
> > > 
> > >  ==================================================================
> > > [  422.214237] BUG: KASAN: slab-out-of-bounds in rtw_cmd_thread+0x1e8/0x430
> > > [r8188eu]
> > > [  422.214277] Write of size 3600 at addr ffff8881e149d200 by task
> > > RTW_CMD_THREAD/2563
> > > 
> > > [  422.214289] CPU: 11 PID: 2563 Comm: RTW_CMD_THREAD Tainted: G C OE
> > > 5.18.0-rc2-staging+ #47 94e3ca73bebf5b7fec506721475e4fff2a023bb9
> > > [  422.214301] Hardware name: Gigabyte Technology Co., Ltd. B550M S2H/B550M
> > > S2H, BIOS F15a 02/16/2022
> > > [  422.214309] Call Trace:
> > > [  422.214313]  <TASK>
> > > [  422.214317]  dump_stack_lvl+0x45/0x5b
> > > [  422.214327]  print_report.cold+0x5e/0x5dc
> > > [  422.214335]  ? kasan_set_track+0x21/0x30
> > > [  422.214342]  ? kasan_set_free_info+0x20/0x40
> > > [  422.214349]  ? rtw_cmd_thread+0x1e8/0x430 [r8188eu
> > > 91924fe1575bf49b9b37985ffde2c585d847446d]
> > > [  422.214386]  kasan_report+0xab/0x120
> > > [  422.214394]  ? rtw_cmd_thread+0x1e8/0x430 [r8188eu
> > > 91924fe1575bf49b9b37985ffde2c585d847446d]
> > > [  422.214430]  kasan_check_range+0xf6/0x1d0
> > > [  422.214436]  memcpy+0x39/0x60
> > > [  422.214442]  rtw_cmd_thread+0x1e8/0x430 [r8188eu
> > > 91924fe1575bf49b9b37985ffde2c585d847446d]
> > > [  422.214479]  ? rtw_setassocsta_cmdrsp_callback+0xd0/0xd0 [r8188eu
> > > 91924fe1575bf49b9b37985ffde2c585d847446d]
> > > [  422.214516]  kthread+0x15d/0x190
> > > [  422.214523]  ? kthread_complete_and_exit+0x20/0x20
> > > [  422.214531]  ret_from_fork+0x22/0x30
> > > [  422.214540]  </TASK>
> > 
> > Sorry, I am not familiar with KASAN. How should I interpret this output?
> > I see the paragraph above has references to rtw_cmd_thread. I assume
> > that is its way of indicating that rtw_cmd_thread is the cause of the
> > problem, but the one below refers to other functions. I'm not sure where
> > I should start looking. I would start looking at `rtw_sitesurvey_cmd` and
> > `rtw_scan_ch_decision`, which call the memcpy on the
> > rtw_ieee80211_channel structure, but they are not on the call trace.
> > 
> 
> drivers/staging/r8188eu/core/rtw_cmd.c:276: memcpy() call.
> 

What git hash are you on?  Is that the line:

	memcpy(&psurveyPara->ch[i], &ch[i], sizeof(struct ieee80211_channel));

Are you sure that's the line which crashes?  According to Smatch and my
simple grep that's dead code because "ch" is always NULL.

> As Michael said the sizes of structures do not mach and the memcpy writes
> below allocated buffer.

I feel a bit bad for not spotting this in review because I was looking
for that kind of bug.  I still don't immediately spot where the bug is.

regards,
dan carpenter

Re: [BUG] staging: r8188eu: KASAN: slab-out-of-bounds in rtw_cmd_thread

[Solomon Tan]

On Mon, Apr 25, 2022 at 06:41:38PM +0300, Dan Carpenter wrote:
> On Sun, Apr 24, 2022 at 06:06:32PM +0300, Pavel Skripkin wrote:
> > Hi Solomon,
> > 
> > On 4/24/22 15:11, Solomon Tan wrote:
> > > On Sun, Apr 24, 2022 at 12:00:12PM +0200, Michael Straube wrote:
> > > > Hi,
> > > > 
> > > > It looks like
> > > > commit 0afaa121813e ("staging: r8188eu: use in-kernel ieee channel")
> > > > intoduced a. See KASAN output below.
> > > > 
> > > > That commit replaced the use of struct rtw_ieee80211_channel with struct
> > > > ieee80211_channel.
> > > > 
> > > > There are several calls to memcpy that used sizeof(struct
> > > > rtw_ieee80211_channel)
> > > > and now use sizeof(struct ieee80211_channel) but the sizes of these two
> > > > structures are not equal.
> > > > 
> > > 
> > > Oh no. When does this issue get triggered?
> > > 
> > > > regards,
> > > > Michael
> > > > 
> > > > dmesg:
> > > > 
> > > >  ==================================================================
> > > > [  422.214237] BUG: KASAN: slab-out-of-bounds in rtw_cmd_thread+0x1e8/0x430
> > > > [r8188eu]
> > > > [  422.214277] Write of size 3600 at addr ffff8881e149d200 by task
> > > > RTW_CMD_THREAD/2563
> > > > 
> > > > [  422.214289] CPU: 11 PID: 2563 Comm: RTW_CMD_THREAD Tainted: G C OE
> > > > 5.18.0-rc2-staging+ #47 94e3ca73bebf5b7fec506721475e4fff2a023bb9
> > > > [  422.214301] Hardware name: Gigabyte Technology Co., Ltd. B550M S2H/B550M
> > > > S2H, BIOS F15a 02/16/2022
> > > > [  422.214309] Call Trace:
> > > > [  422.214313]  <TASK>
> > > > [  422.214317]  dump_stack_lvl+0x45/0x5b
> > > > [  422.214327]  print_report.cold+0x5e/0x5dc
> > > > [  422.214335]  ? kasan_set_track+0x21/0x30
> > > > [  422.214342]  ? kasan_set_free_info+0x20/0x40
> > > > [  422.214349]  ? rtw_cmd_thread+0x1e8/0x430 [r8188eu
> > > > 91924fe1575bf49b9b37985ffde2c585d847446d]
> > > > [  422.214386]  kasan_report+0xab/0x120
> > > > [  422.214394]  ? rtw_cmd_thread+0x1e8/0x430 [r8188eu
> > > > 91924fe1575bf49b9b37985ffde2c585d847446d]
> > > > [  422.214430]  kasan_check_range+0xf6/0x1d0
> > > > [  422.214436]  memcpy+0x39/0x60
> > > > [  422.214442]  rtw_cmd_thread+0x1e8/0x430 [r8188eu
> > > > 91924fe1575bf49b9b37985ffde2c585d847446d]
> > > > [  422.214479]  ? rtw_setassocsta_cmdrsp_callback+0xd0/0xd0 [r8188eu
> > > > 91924fe1575bf49b9b37985ffde2c585d847446d]
> > > > [  422.214516]  kthread+0x15d/0x190
> > > > [  422.214523]  ? kthread_complete_and_exit+0x20/0x20
> > > > [  422.214531]  ret_from_fork+0x22/0x30
> > > > [  422.214540]  </TASK>
> > > 
> > > Sorry, I am not familiar with KASAN. How should I interpret this output?
> > > I see the paragraph above has references to rtw_cmd_thread. I assume
> > > that is its way of indicating that rtw_cmd_thread is the cause of the
> > > problem, but the one below refers to other functions. I'm not sure where
> > > I should start looking. I would start looking at `rtw_sitesurvey_cmd` and
> > > `rtw_scan_ch_decision`, which call the memcpy on the
> > > rtw_ieee80211_channel structure, but they are not on the call trace.
> > > 
> > 
> > drivers/staging/r8188eu/core/rtw_cmd.c:276: memcpy() call.
> > 
> 
> What git hash are you on?  Is that the line:
> 
> 	memcpy(&psurveyPara->ch[i], &ch[i], sizeof(struct ieee80211_channel));
> 
> Are you sure that's the line which crashes?  According to Smatch and my
> simple grep that's dead code because "ch" is always NULL.
>

I don't think Pavel is referring to that line as it belongs to the
`rtw_sitesurvey_cmd` function. That func didnt appear in the dmesg output.
Rather I think Pavel refers to line 267, which is
`memcpy(pcmdbuf, pcmd->parmbuf, pcmd->cmdsz);` from function
`rtw_cmd_thread`. Changing rtw_ieee80211_channel to ieee80211_channel
must have messed up that line somewhere but I just can't figure out what
or why.
 
> > As Michael said the sizes of structures do not mach and the memcpy writes
> > below allocated buffer.
> 
> I feel a bit bad for not spotting this in review because I was looking
> for that kind of bug.  I still don't immediately spot where the bug is.

Sorry I put you in this position, Dan.

> 
> regards,
> dan carpenter