* Re: [PATCHv3] dvb: usb: fix use after free in dvb_usb_device_exit
2019-04-30 12:16 [PATCHv3] dvb: usb: fix use after free in dvb_usb_device_exit Oliver Neukum
@ 2019-04-30 12:32 ` Mauro Carvalho Chehab
2019-05-03 5:10 ` kbuild test robot
1 sibling, 0 replies; 3+ messages in thread
From: Mauro Carvalho Chehab @ 2019-04-30 12:32 UTC (permalink / raw)
To: Oliver Neukum; +Cc: linux-media
Em Tue, 30 Apr 2019 14:16:07 +0200
Oliver Neukum <oneukum@suse.com> escreveu:
> dvb_usb_device_exit() frees and uses the device name in that order
> Fix by storing the name in a buffer before freeing it
>
> v2: fixed style issues
> v3: strscpy used and variable names changed
>
> Signed-off-by: Oliver Neukum <oneukum@suse.com>
> Reported-by: syzbot+26ec41e9f788b3eba396@syzkaller.appspotmail.com
> ---
> drivers/media/usb/dvb-usb/dvb-usb-init.c | 7 +++++--
> 1 file changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/media/usb/dvb-usb/dvb-usb-init.c b/drivers/media/usb/dvb-usb/dvb-usb-init.c
> index 99951e02a880..48d17736db5d 100644
> --- a/drivers/media/usb/dvb-usb/dvb-usb-init.c
> +++ b/drivers/media/usb/dvb-usb/dvb-usb-init.c
> @@ -287,12 +287,15 @@ EXPORT_SYMBOL(dvb_usb_device_init);
> void dvb_usb_device_exit(struct usb_interface *intf)
> {
> struct dvb_usb_device *d = usb_get_intfdata(intf);
> - const char *name = "generic DVB-USB module";
> + const char *default_name = "generic DVB-USB module";
> + char name[40];
>
> usb_set_intfdata(intf, NULL);
> if (d != NULL && d->desc != NULL) {
> - name = d->desc->name;
> + strscpy(name, d->desc->name, sizeof(name));
> dvb_usb_exit(d);
> + } else {
> + memcpy(name, default_name, sizeof(name));
Please use strscpy() here too, as we're using it everywhere
when a string requires copy inside media.
> }
> info("%s successfully deinitialized and disconnected.", name);
>
Thanks,
Mauro
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCHv3] dvb: usb: fix use after free in dvb_usb_device_exit
2019-04-30 12:16 [PATCHv3] dvb: usb: fix use after free in dvb_usb_device_exit Oliver Neukum
2019-04-30 12:32 ` Mauro Carvalho Chehab
@ 2019-05-03 5:10 ` kbuild test robot
1 sibling, 0 replies; 3+ messages in thread
From: kbuild test robot @ 2019-05-03 5:10 UTC (permalink / raw)
To: Oliver Neukum; +Cc: kbuild-all, mchehab, linux-media, Oliver Neukum
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Hi Oliver,
I love your patch! Yet something to improve:
[auto build test ERROR on linuxtv-media/master]
[also build test ERROR on v5.1-rc7 next-20190502]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
url: https://github.com/0day-ci/linux/commits/Oliver-Neukum/dvb-usb-fix-use-after-free-in-dvb_usb_device_exit/20190503-112248
base: git://linuxtv.org/media_tree.git master
config: i386-randconfig-x003-201917 (attached as .config)
compiler: gcc-7 (Debian 7.3.0-1) 7.3.0
reproduce:
# save the attached .config to linux build tree
make ARCH=i386
If you fix the issue, kindly add following tag
Reported-by: kbuild test robot <lkp@intel.com>
All errors (new ones prefixed by >>):
Cyclomatic Complexity 1 arch/x86/include/asm/bitops.h:fls
Cyclomatic Complexity 1 include/linux/log2.h:__ilog2_u32
Cyclomatic Complexity 4 include/linux/string.h:memcpy
Cyclomatic Complexity 1 include/asm-generic/getorder.h:__get_order
Cyclomatic Complexity 1 include/linux/device.h:dev_get_drvdata
Cyclomatic Complexity 1 include/linux/device.h:dev_set_drvdata
Cyclomatic Complexity 1 include/linux/usb.h:usb_get_intfdata
Cyclomatic Complexity 1 include/linux/usb.h:usb_set_intfdata
Cyclomatic Complexity 1 include/linux/usb.h:interface_to_usbdev
Cyclomatic Complexity 1 include/linux/usb.h:__create_pipe
Cyclomatic Complexity 3 include/linux/slab.h:kmalloc_type
Cyclomatic Complexity 28 include/linux/slab.h:kmalloc_index
Cyclomatic Complexity 67 include/linux/slab.h:kmalloc_large
Cyclomatic Complexity 4 include/linux/slab.h:kmalloc
Cyclomatic Complexity 1 include/linux/slab.h:kzalloc
Cyclomatic Complexity 15 drivers/media/usb/dvb-usb/dvb-usb-init.c:dvb_usb_find_device
Cyclomatic Complexity 20 drivers/media/usb/dvb-usb/dvb-usb-init.c:dvb_usb_adapter_init
Cyclomatic Complexity 2 drivers/media/usb/dvb-usb/dvb-usb-init.c:dvb_usb_adapter_exit
Cyclomatic Complexity 3 drivers/media/usb/dvb-usb/dvb-usb-init.c:dvb_usb_exit
Cyclomatic Complexity 3 drivers/media/usb/dvb-usb/dvb-usb-init.c:dvb_usb_device_exit
Cyclomatic Complexity 7 drivers/media/usb/dvb-usb/dvb-usb-init.c:dvb_usb_device_power_ctrl
Cyclomatic Complexity 6 drivers/media/usb/dvb-usb/dvb-usb-init.c:dvb_usb_init
Cyclomatic Complexity 10 drivers/media/usb/dvb-usb/dvb-usb-init.c:dvb_usb_device_init
In file included from arch/x86/include/asm/page_32.h:35:0,
from arch/x86/include/asm/page.h:14,
from arch/x86/include/asm/thread_info.h:12,
from include/linux/thread_info.h:38,
from arch/x86/include/asm/preempt.h:7,
from include/linux/preempt.h:78,
from include/linux/spinlock.h:51,
from include/linux/seqlock.h:36,
from include/linux/time.h:6,
from include/linux/input.h:11,
from drivers/media/usb/dvb-usb/dvb-usb.h:14,
from drivers/media/usb/dvb-usb/dvb-usb-common.h:13,
from drivers/media/usb/dvb-usb/dvb-usb-init.c:14:
In function 'memcpy',
inlined from 'dvb_usb_device_exit' at drivers/media/usb/dvb-usb/dvb-usb-init.c:298:3:
>> include/linux/string.h:348:4: error: call to '__read_overflow2' declared with attribute error: detected read beyond size of object passed as 2nd parameter
__read_overflow2();
^~~~~~~~~~~~~~~~~~
--
Cyclomatic Complexity 1 arch/x86/include/asm/bitops.h:fls
Cyclomatic Complexity 1 include/linux/log2.h:__ilog2_u32
Cyclomatic Complexity 4 include/linux/string.h:memcpy
Cyclomatic Complexity 1 include/asm-generic/getorder.h:__get_order
Cyclomatic Complexity 1 include/linux/device.h:dev_get_drvdata
Cyclomatic Complexity 1 include/linux/device.h:dev_set_drvdata
Cyclomatic Complexity 1 include/linux/usb.h:usb_get_intfdata
Cyclomatic Complexity 1 include/linux/usb.h:usb_set_intfdata
Cyclomatic Complexity 1 include/linux/usb.h:interface_to_usbdev
Cyclomatic Complexity 1 include/linux/usb.h:__create_pipe
Cyclomatic Complexity 3 include/linux/slab.h:kmalloc_type
Cyclomatic Complexity 28 include/linux/slab.h:kmalloc_index
Cyclomatic Complexity 67 include/linux/slab.h:kmalloc_large
Cyclomatic Complexity 4 include/linux/slab.h:kmalloc
Cyclomatic Complexity 1 include/linux/slab.h:kzalloc
Cyclomatic Complexity 15 drivers/media//usb/dvb-usb/dvb-usb-init.c:dvb_usb_find_device
Cyclomatic Complexity 20 drivers/media//usb/dvb-usb/dvb-usb-init.c:dvb_usb_adapter_init
Cyclomatic Complexity 2 drivers/media//usb/dvb-usb/dvb-usb-init.c:dvb_usb_adapter_exit
Cyclomatic Complexity 3 drivers/media//usb/dvb-usb/dvb-usb-init.c:dvb_usb_exit
Cyclomatic Complexity 3 drivers/media//usb/dvb-usb/dvb-usb-init.c:dvb_usb_device_exit
Cyclomatic Complexity 7 drivers/media//usb/dvb-usb/dvb-usb-init.c:dvb_usb_device_power_ctrl
Cyclomatic Complexity 6 drivers/media//usb/dvb-usb/dvb-usb-init.c:dvb_usb_init
Cyclomatic Complexity 10 drivers/media//usb/dvb-usb/dvb-usb-init.c:dvb_usb_device_init
In file included from arch/x86/include/asm/page_32.h:35:0,
from arch/x86/include/asm/page.h:14,
from arch/x86/include/asm/thread_info.h:12,
from include/linux/thread_info.h:38,
from arch/x86/include/asm/preempt.h:7,
from include/linux/preempt.h:78,
from include/linux/spinlock.h:51,
from include/linux/seqlock.h:36,
from include/linux/time.h:6,
from include/linux/input.h:11,
from drivers/media//usb/dvb-usb/dvb-usb.h:14,
from drivers/media//usb/dvb-usb/dvb-usb-common.h:13,
from drivers/media//usb/dvb-usb/dvb-usb-init.c:14:
In function 'memcpy',
inlined from 'dvb_usb_device_exit' at drivers/media//usb/dvb-usb/dvb-usb-init.c:298:3:
>> include/linux/string.h:348:4: error: call to '__read_overflow2' declared with attribute error: detected read beyond size of object passed as 2nd parameter
__read_overflow2();
^~~~~~~~~~~~~~~~~~
vim +/__read_overflow2 +348 include/linux/string.h
6974f0c4 Daniel Micay 2017-07-12 339
6974f0c4 Daniel Micay 2017-07-12 340 __FORTIFY_INLINE void *memcpy(void *p, const void *q, __kernel_size_t size)
6974f0c4 Daniel Micay 2017-07-12 341 {
6974f0c4 Daniel Micay 2017-07-12 342 size_t p_size = __builtin_object_size(p, 0);
6974f0c4 Daniel Micay 2017-07-12 343 size_t q_size = __builtin_object_size(q, 0);
6974f0c4 Daniel Micay 2017-07-12 344 if (__builtin_constant_p(size)) {
6974f0c4 Daniel Micay 2017-07-12 345 if (p_size < size)
6974f0c4 Daniel Micay 2017-07-12 346 __write_overflow();
6974f0c4 Daniel Micay 2017-07-12 347 if (q_size < size)
6974f0c4 Daniel Micay 2017-07-12 @348 __read_overflow2();
6974f0c4 Daniel Micay 2017-07-12 349 }
6974f0c4 Daniel Micay 2017-07-12 350 if (p_size < size || q_size < size)
6974f0c4 Daniel Micay 2017-07-12 351 fortify_panic(__func__);
6974f0c4 Daniel Micay 2017-07-12 352 return __builtin_memcpy(p, q, size);
6974f0c4 Daniel Micay 2017-07-12 353 }
6974f0c4 Daniel Micay 2017-07-12 354
:::::: The code at line 348 was first introduced by commit
:::::: 6974f0c4555e285ab217cee58b6e874f776ff409 include/linux/string.h: add the option of fortified string.h functions
:::::: TO: Daniel Micay <danielmicay@gmail.com>
:::::: CC: Linus Torvalds <torvalds@linux-foundation.org>
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
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^ permalink raw reply [flat|nested] 3+ messages in thread