* [PATCH net 2/5] netdevsim: fix stack-out-of-bounds in nsim_dev_debugfs_init()
@ 2020-01-11 16:37 Taehee Yoo
2020-01-12 13:47 ` Jakub Kicinski
0 siblings, 1 reply; 3+ messages in thread
From: Taehee Yoo @ 2020-01-11 16:37 UTC (permalink / raw)
To: davem, jakub.kicinski, netdev; +Cc: ap420073
When netdevsim dev is being created, a debugfs directory is created.
The variable "dev_ddir_name" is 16bytes device name pointer and device
name is "netdevsim<dev id>".
The maximum dev id length is 10.
So, 16bytes for device name isn't enough.
Test commands:
modprobe netdevsim
echo "1000000000 0" > /sys/bus/netdevsim/new_device
Splat looks like:
[ 90.624922][ T1000] BUG: KASAN: stack-out-of-bounds in number+0x824/0x880
[ 90.626999][ T1000] Write of size 1 at addr ffff8880b7f47988 by task bash/1000
[ 90.627798][ T1000]
[ 90.628076][ T1000] CPU: 0 PID: 1000 Comm: bash Not tainted 5.5.0-rc5+ #270
[ 90.628806][ T1000] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
[ 90.629752][ T1000] Call Trace:
[ 90.630080][ T1000] dump_stack+0x96/0xdb
[ 90.630512][ T1000] ? number+0x824/0x880
[ 90.630939][ T1000] print_address_description.constprop.5+0x1be/0x360
[ 90.631610][ T1000] ? number+0x824/0x880
[ 90.632038][ T1000] ? number+0x824/0x880
[ 90.632469][ T1000] __kasan_report+0x12a/0x16f
[ 90.632939][ T1000] ? number+0x824/0x880
[ 90.633397][ T1000] kasan_report+0xe/0x20
[ 90.633954][ T1000] number+0x824/0x880
[ 90.634513][ T1000] ? put_dec+0xa0/0xa0
[ 90.635047][ T1000] ? rcu_read_lock_sched_held+0x90/0xc0
[ 90.636469][ T1000] vsnprintf+0x63c/0x10b0
[ 90.637187][ T1000] ? pointer+0x5b0/0x5b0
[ 90.637871][ T1000] ? mark_lock+0x11d/0xc40
[ 90.638591][ T1000] sprintf+0x9b/0xd0
[ 90.639164][ T1000] ? scnprintf+0xe0/0xe0
[ 90.639802][ T1000] nsim_dev_probe+0x63c/0xbf0 [netdevsim]
[ ... ]
Fixes: 83c9e13aa39a ("netdevsim: add software driver for testing offloads")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
---
drivers/net/netdevsim/dev.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/netdevsim/dev.c b/drivers/net/netdevsim/dev.c
index 634eb5cdcbbe..a0c80a70bb23 100644
--- a/drivers/net/netdevsim/dev.c
+++ b/drivers/net/netdevsim/dev.c
@@ -88,7 +88,7 @@ static const struct file_operations nsim_dev_take_snapshot_fops = {
static int nsim_dev_debugfs_init(struct nsim_dev *nsim_dev)
{
- char dev_ddir_name[16];
+ char dev_ddir_name[32];
sprintf(dev_ddir_name, DRV_NAME "%u", nsim_dev->nsim_bus_dev->dev.id);
nsim_dev->ddir = debugfs_create_dir(dev_ddir_name, nsim_dev_ddir);
--
2.17.1
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH net 2/5] netdevsim: fix stack-out-of-bounds in nsim_dev_debugfs_init()
2020-01-11 16:37 [PATCH net 2/5] netdevsim: fix stack-out-of-bounds in nsim_dev_debugfs_init() Taehee Yoo
@ 2020-01-12 13:47 ` Jakub Kicinski
2020-01-13 13:57 ` Taehee Yoo
0 siblings, 1 reply; 3+ messages in thread
From: Jakub Kicinski @ 2020-01-12 13:47 UTC (permalink / raw)
To: Taehee Yoo; +Cc: davem, netdev
On Sat, 11 Jan 2020 16:37:09 +0000, Taehee Yoo wrote:
> When netdevsim dev is being created, a debugfs directory is created.
> The variable "dev_ddir_name" is 16bytes device name pointer and device
> name is "netdevsim<dev id>".
> The maximum dev id length is 10.
> So, 16bytes for device name isn't enough.
>
> Test commands:
> modprobe netdevsim
> echo "1000000000 0" > /sys/bus/netdevsim/new_device
>
> Splat looks like:
> [ 90.624922][ T1000] BUG: KASAN: stack-out-of-bounds in number+0x824/0x880
> [ 90.626999][ T1000] Write of size 1 at addr ffff8880b7f47988 by task bash/1000
> [ 90.627798][ T1000]
> [ 90.628076][ T1000] CPU: 0 PID: 1000 Comm: bash Not tainted 5.5.0-rc5+ #270
> [ 90.628806][ T1000] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
> [ 90.629752][ T1000] Call Trace:
> [ 90.630080][ T1000] dump_stack+0x96/0xdb
> [ 90.630512][ T1000] ? number+0x824/0x880
> [ 90.630939][ T1000] print_address_description.constprop.5+0x1be/0x360
> [ 90.631610][ T1000] ? number+0x824/0x880
> [ 90.632038][ T1000] ? number+0x824/0x880
> [ 90.632469][ T1000] __kasan_report+0x12a/0x16f
> [ 90.632939][ T1000] ? number+0x824/0x880
> [ 90.633397][ T1000] kasan_report+0xe/0x20
> [ 90.633954][ T1000] number+0x824/0x880
> [ 90.634513][ T1000] ? put_dec+0xa0/0xa0
> [ 90.635047][ T1000] ? rcu_read_lock_sched_held+0x90/0xc0
> [ 90.636469][ T1000] vsnprintf+0x63c/0x10b0
> [ 90.637187][ T1000] ? pointer+0x5b0/0x5b0
> [ 90.637871][ T1000] ? mark_lock+0x11d/0xc40
> [ 90.638591][ T1000] sprintf+0x9b/0xd0
> [ 90.639164][ T1000] ? scnprintf+0xe0/0xe0
> [ 90.639802][ T1000] nsim_dev_probe+0x63c/0xbf0 [netdevsim]
> [ ... ]
>
> Fixes: 83c9e13aa39a ("netdevsim: add software driver for testing offloads")
The correct Fixes tag is:
Fixes: ab1d0cc004d7 ("netdevsim: change debugfs tree topology")
> Signed-off-by: Taehee Yoo <ap420073@gmail.com>
> ---
> drivers/net/netdevsim/dev.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/netdevsim/dev.c b/drivers/net/netdevsim/dev.c
> index 634eb5cdcbbe..a0c80a70bb23 100644
> --- a/drivers/net/netdevsim/dev.c
> +++ b/drivers/net/netdevsim/dev.c
> @@ -88,7 +88,7 @@ static const struct file_operations nsim_dev_take_snapshot_fops = {
>
> static int nsim_dev_debugfs_init(struct nsim_dev *nsim_dev)
> {
> - char dev_ddir_name[16];
> + char dev_ddir_name[32];
nit: it'd be tempting to size this to the correct value
(20? or sizeof(DRV_NAME) + 10) rather than the arbitrary 32,
perhaps?
> sprintf(dev_ddir_name, DRV_NAME "%u", nsim_dev->nsim_bus_dev->dev.id);
> nsim_dev->ddir = debugfs_create_dir(dev_ddir_name, nsim_dev_ddir);
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH net 2/5] netdevsim: fix stack-out-of-bounds in nsim_dev_debugfs_init()
2020-01-12 13:47 ` Jakub Kicinski
@ 2020-01-13 13:57 ` Taehee Yoo
0 siblings, 0 replies; 3+ messages in thread
From: Taehee Yoo @ 2020-01-13 13:57 UTC (permalink / raw)
To: Jakub Kicinski; +Cc: David Miller, Netdev
On Sun, 12 Jan 2020 at 22:47, Jakub Kicinski <kubakici@wp.pl> wrote:
>
Hi Jakub,
Thank you for your review!
> On Sat, 11 Jan 2020 16:37:09 +0000, Taehee Yoo wrote:
> > When netdevsim dev is being created, a debugfs directory is created.
> > The variable "dev_ddir_name" is 16bytes device name pointer and device
> > name is "netdevsim<dev id>".
> > The maximum dev id length is 10.
> > So, 16bytes for device name isn't enough.
> >
> > Test commands:
> > modprobe netdevsim
> > echo "1000000000 0" > /sys/bus/netdevsim/new_device
> >
> > Splat looks like:
> > [ 90.624922][ T1000] BUG: KASAN: stack-out-of-bounds in number+0x824/0x880
> > [ 90.626999][ T1000] Write of size 1 at addr ffff8880b7f47988 by task bash/1000
> > [ 90.627798][ T1000]
> > [ 90.628076][ T1000] CPU: 0 PID: 1000 Comm: bash Not tainted 5.5.0-rc5+ #270
> > [ 90.628806][ T1000] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
> > [ 90.629752][ T1000] Call Trace:
> > [ 90.630080][ T1000] dump_stack+0x96/0xdb
> > [ 90.630512][ T1000] ? number+0x824/0x880
> > [ 90.630939][ T1000] print_address_description.constprop.5+0x1be/0x360
> > [ 90.631610][ T1000] ? number+0x824/0x880
> > [ 90.632038][ T1000] ? number+0x824/0x880
> > [ 90.632469][ T1000] __kasan_report+0x12a/0x16f
> > [ 90.632939][ T1000] ? number+0x824/0x880
> > [ 90.633397][ T1000] kasan_report+0xe/0x20
> > [ 90.633954][ T1000] number+0x824/0x880
> > [ 90.634513][ T1000] ? put_dec+0xa0/0xa0
> > [ 90.635047][ T1000] ? rcu_read_lock_sched_held+0x90/0xc0
> > [ 90.636469][ T1000] vsnprintf+0x63c/0x10b0
> > [ 90.637187][ T1000] ? pointer+0x5b0/0x5b0
> > [ 90.637871][ T1000] ? mark_lock+0x11d/0xc40
> > [ 90.638591][ T1000] sprintf+0x9b/0xd0
> > [ 90.639164][ T1000] ? scnprintf+0xe0/0xe0
> > [ 90.639802][ T1000] nsim_dev_probe+0x63c/0xbf0 [netdevsim]
> > [ ... ]
> >
> > Fixes: 83c9e13aa39a ("netdevsim: add software driver for testing offloads")
>
> The correct Fixes tag is:
>
> Fixes: ab1d0cc004d7 ("netdevsim: change debugfs tree topology")
>
Thank you! I will fix the Fixes tag.
> > Signed-off-by: Taehee Yoo <ap420073@gmail.com>
> > ---
> > drivers/net/netdevsim/dev.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/net/netdevsim/dev.c b/drivers/net/netdevsim/dev.c
> > index 634eb5cdcbbe..a0c80a70bb23 100644
> > --- a/drivers/net/netdevsim/dev.c
> > +++ b/drivers/net/netdevsim/dev.c
> > @@ -88,7 +88,7 @@ static const struct file_operations nsim_dev_take_snapshot_fops = {
> >
> > static int nsim_dev_debugfs_init(struct nsim_dev *nsim_dev)
> > {
> > - char dev_ddir_name[16];
> > + char dev_ddir_name[32];
>
> nit: it'd be tempting to size this to the correct value
> (20? or sizeof(DRV_NAME) + 10) rather than the arbitrary 32,
> perhaps?
>
I agree with this. This is more correct.
I will fix this too.
Thank you
Taehee Yoo.
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2020-01-13 13:57 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2020-01-11 16:37 [PATCH net 2/5] netdevsim: fix stack-out-of-bounds in nsim_dev_debugfs_init() Taehee Yoo
2020-01-12 13:47 ` Jakub Kicinski
2020-01-13 13:57 ` Taehee Yoo
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