diff mbox series

[net,v1] drivers/net/bonding: Fix out-of-bounds read in bond_option_arp_ip_targets_set()

Message ID CAEkJfYPYF-nNB2oiXfXwjPG0VVB2Bd8Q8kAq+74J=R+4HkngWw@mail.gmail.com (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series [net,v1] drivers/net/bonding: Fix out-of-bounds read in bond_option_arp_ip_targets_set() | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for net
netdev/apply fail Patch does not apply to net-0

Commit Message

Sam Sun April 15, 2024, 3:40 a.m. UTC
In function bond_option_arp_ip_targets_set(), if newval->string is an
empty string, newval->string+1 will point to the byte after the
string, causing an out-of-bound read.

BUG: KASAN: slab-out-of-bounds in strlen+0x7d/0xa0 lib/string.c:418
Read of size 1 at addr ffff8881119c4781 by task syz-executor665/8107
CPU: 1 PID: 8107 Comm: syz-executor665 Not tainted 6.7.0-rc7 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:364 [inline]
 print_report+0xc1/0x5e0 mm/kasan/report.c:475
 kasan_report+0xbe/0xf0 mm/kasan/report.c:588
 strlen+0x7d/0xa0 lib/string.c:418
 __fortify_strlen include/linux/fortify-string.h:210 [inline]
 in4_pton+0xa3/0x3f0 net/core/utils.c:130
 bond_option_arp_ip_targets_set+0xc2/0x910
drivers/net/bonding/bond_options.c:1201
 __bond_opt_set+0x2a4/0x1030 drivers/net/bonding/bond_options.c:767
 __bond_opt_set_notify+0x48/0x150 drivers/net/bonding/bond_options.c:792
 bond_opt_tryset_rtnl+0xda/0x160 drivers/net/bonding/bond_options.c:817
 bonding_sysfs_store_option+0xa1/0x120 drivers/net/bonding/bond_sysfs.c:156
 dev_attr_store+0x54/0x80 drivers/base/core.c:2366
 sysfs_kf_write+0x114/0x170 fs/sysfs/file.c:136
 kernfs_fop_write_iter+0x337/0x500 fs/kernfs/file.c:334
 call_write_iter include/linux/fs.h:2020 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x96a/0xd80 fs/read_write.c:584
 ksys_write+0x122/0x250 fs/read_write.c:637
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x40/0x110 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b
---[ end trace ]---

Fix it by adding a check of string length before using it.

Reported-by: Yue Sun <samsun1006219@gmail.com>
Signed-off-by: Yue Sun <samsun1006219@gmail.com>
---
 drivers/net/bonding/bond_options.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

             return ret;

Comments

Hangbin Liu April 15, 2024, 7:32 a.m. UTC | #1
On Mon, Apr 15, 2024 at 11:40:31AM +0800, Sam Sun wrote:
> In function bond_option_arp_ip_targets_set(), if newval->string is an
> empty string, newval->string+1 will point to the byte after the
> string, causing an out-of-bound read.
> 
> BUG: KASAN: slab-out-of-bounds in strlen+0x7d/0xa0 lib/string.c:418
> Read of size 1 at addr ffff8881119c4781 by task syz-executor665/8107
> CPU: 1 PID: 8107 Comm: syz-executor665 Not tainted 6.7.0-rc7 #1
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
> Call Trace:
>  <TASK>
>  __dump_stack lib/dump_stack.c:88 [inline]
>  dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106
>  print_address_description mm/kasan/report.c:364 [inline]
>  print_report+0xc1/0x5e0 mm/kasan/report.c:475
>  kasan_report+0xbe/0xf0 mm/kasan/report.c:588
>  strlen+0x7d/0xa0 lib/string.c:418
>  __fortify_strlen include/linux/fortify-string.h:210 [inline]
>  in4_pton+0xa3/0x3f0 net/core/utils.c:130
>  bond_option_arp_ip_targets_set+0xc2/0x910
> drivers/net/bonding/bond_options.c:1201
>  __bond_opt_set+0x2a4/0x1030 drivers/net/bonding/bond_options.c:767
>  __bond_opt_set_notify+0x48/0x150 drivers/net/bonding/bond_options.c:792
>  bond_opt_tryset_rtnl+0xda/0x160 drivers/net/bonding/bond_options.c:817
>  bonding_sysfs_store_option+0xa1/0x120 drivers/net/bonding/bond_sysfs.c:156
>  dev_attr_store+0x54/0x80 drivers/base/core.c:2366
>  sysfs_kf_write+0x114/0x170 fs/sysfs/file.c:136
>  kernfs_fop_write_iter+0x337/0x500 fs/kernfs/file.c:334
>  call_write_iter include/linux/fs.h:2020 [inline]
>  new_sync_write fs/read_write.c:491 [inline]
>  vfs_write+0x96a/0xd80 fs/read_write.c:584
>  ksys_write+0x122/0x250 fs/read_write.c:637
>  do_syscall_x64 arch/x86/entry/common.c:52 [inline]
>  do_syscall_64+0x40/0x110 arch/x86/entry/common.c:83
>  entry_SYSCALL_64_after_hwframe+0x63/0x6b
> ---[ end trace ]---
> 
> Fix it by adding a check of string length before using it.
> 
> Reported-by: Yue Sun <samsun1006219@gmail.com>

Not sure if there is a need to add Reported-by yourself if you are the author.

Also you need a Fixes tag if the patch target is net tree.

> Signed-off-by: Yue Sun <samsun1006219@gmail.com>
> ---
>  drivers/net/bonding/bond_options.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/bonding/bond_options.c
> b/drivers/net/bonding/bond_options.c
> index 4cdbc7e084f4..db8d99ca1de0 100644
> --- a/drivers/net/bonding/bond_options.c
> +++ b/drivers/net/bonding/bond_options.c
> @@ -1214,7 +1214,8 @@ static int bond_option_arp_ip_targets_set(struct
> bonding *bond,
>      __be32 target;
> 
>      if (newval->string) {
> -        if (!in4_pton(newval->string+1, -1, (u8 *)&target, -1, NULL)) {
> +        if (!(strlen(newval->string)) ||
> +            !in4_pton(newval->string + 1, -1, (u8 *)&target, -1, NULL)) {
>              netdev_err(bond->dev, "invalid ARP target %pI4 specified\n",
>                     &target);

Do we need to init target first if !(strlen(newval->string)) ?

Thanks
Hangbin
>              return ret;
> -- 
> 2.34.1
Sam Sun April 15, 2024, 8:46 a.m. UTC | #2
On Mon, Apr 15, 2024 at 3:32 PM Hangbin Liu <liuhangbin@gmail.com> wrote:
>
> On Mon, Apr 15, 2024 at 11:40:31AM +0800, Sam Sun wrote:
> > In function bond_option_arp_ip_targets_set(), if newval->string is an
> > empty string, newval->string+1 will point to the byte after the
> > string, causing an out-of-bound read.
> >
> > BUG: KASAN: slab-out-of-bounds in strlen+0x7d/0xa0 lib/string.c:418
> > Read of size 1 at addr ffff8881119c4781 by task syz-executor665/8107
> > CPU: 1 PID: 8107 Comm: syz-executor665 Not tainted 6.7.0-rc7 #1
> > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
> > Call Trace:
> >  <TASK>
> >  __dump_stack lib/dump_stack.c:88 [inline]
> >  dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106
> >  print_address_description mm/kasan/report.c:364 [inline]
> >  print_report+0xc1/0x5e0 mm/kasan/report.c:475
> >  kasan_report+0xbe/0xf0 mm/kasan/report.c:588
> >  strlen+0x7d/0xa0 lib/string.c:418
> >  __fortify_strlen include/linux/fortify-string.h:210 [inline]
> >  in4_pton+0xa3/0x3f0 net/core/utils.c:130
> >  bond_option_arp_ip_targets_set+0xc2/0x910
> > drivers/net/bonding/bond_options.c:1201
> >  __bond_opt_set+0x2a4/0x1030 drivers/net/bonding/bond_options.c:767
> >  __bond_opt_set_notify+0x48/0x150 drivers/net/bonding/bond_options.c:792
> >  bond_opt_tryset_rtnl+0xda/0x160 drivers/net/bonding/bond_options.c:817
> >  bonding_sysfs_store_option+0xa1/0x120 drivers/net/bonding/bond_sysfs.c:156
> >  dev_attr_store+0x54/0x80 drivers/base/core.c:2366
> >  sysfs_kf_write+0x114/0x170 fs/sysfs/file.c:136
> >  kernfs_fop_write_iter+0x337/0x500 fs/kernfs/file.c:334
> >  call_write_iter include/linux/fs.h:2020 [inline]
> >  new_sync_write fs/read_write.c:491 [inline]
> >  vfs_write+0x96a/0xd80 fs/read_write.c:584
> >  ksys_write+0x122/0x250 fs/read_write.c:637
> >  do_syscall_x64 arch/x86/entry/common.c:52 [inline]
> >  do_syscall_64+0x40/0x110 arch/x86/entry/common.c:83
> >  entry_SYSCALL_64_after_hwframe+0x63/0x6b
> > ---[ end trace ]---
> >
> > Fix it by adding a check of string length before using it.
> >
> > Reported-by: Yue Sun <samsun1006219@gmail.com>
>
> Not sure if there is a need to add Reported-by yourself if you are the author.
>
> Also you need a Fixes tag if the patch target is net tree.

Sorry for missing the Fixes tag, I will add it to patch. I am also not
sure if I should add Reported-by here, since it's my first time to
commit a patch for linux.

> > Signed-off-by: Yue Sun <samsun1006219@gmail.com>
> > ---
> >  drivers/net/bonding/bond_options.c | 3 ++-
> >  1 file changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/net/bonding/bond_options.c
> > b/drivers/net/bonding/bond_options.c
> > index 4cdbc7e084f4..db8d99ca1de0 100644
> > --- a/drivers/net/bonding/bond_options.c
> > +++ b/drivers/net/bonding/bond_options.c
> > @@ -1214,7 +1214,8 @@ static int bond_option_arp_ip_targets_set(struct
> > bonding *bond,
> >      __be32 target;
> >
> >      if (newval->string) {
> > -        if (!in4_pton(newval->string+1, -1, (u8 *)&target, -1, NULL)) {
> > +        if (!(strlen(newval->string)) ||
> > +            !in4_pton(newval->string + 1, -1, (u8 *)&target, -1, NULL)) {
> >              netdev_err(bond->dev, "invalid ARP target %pI4 specified\n",
> >                     &target);
>
> Do we need to init target first if !(strlen(newval->string)) ?
>
Good question. I think we don't need to init target first, since in
original logic in4_pton() also leave target untouched if any error
occurs. If !(strlen(newval->string)), bond_option_arp_ip_targets_set()
just ret and target is still untouched. But I am not sure about it.

If anyone finds other problems, please let me know.

Thanks,
Yue
> Thanks
> Hangbin
> >              return ret;
> > --
> > 2.34.1
Jay Vosburgh April 15, 2024, 3:43 p.m. UTC | #3
Sam Sun <samsun1006219@gmail.com> wrote:

>On Mon, Apr 15, 2024 at 3:32 PM Hangbin Liu <liuhangbin@gmail.com> wrote:
>>
>> On Mon, Apr 15, 2024 at 11:40:31AM +0800, Sam Sun wrote:
>> > In function bond_option_arp_ip_targets_set(), if newval->string is an
>> > empty string, newval->string+1 will point to the byte after the
>> > string, causing an out-of-bound read.
>> >
>> > BUG: KASAN: slab-out-of-bounds in strlen+0x7d/0xa0 lib/string.c:418
>> > Read of size 1 at addr ffff8881119c4781 by task syz-executor665/8107
>> > CPU: 1 PID: 8107 Comm: syz-executor665 Not tainted 6.7.0-rc7 #1
>> > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
>> > Call Trace:
>> >  <TASK>
>> >  __dump_stack lib/dump_stack.c:88 [inline]
>> >  dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106
>> >  print_address_description mm/kasan/report.c:364 [inline]
>> >  print_report+0xc1/0x5e0 mm/kasan/report.c:475
>> >  kasan_report+0xbe/0xf0 mm/kasan/report.c:588
>> >  strlen+0x7d/0xa0 lib/string.c:418
>> >  __fortify_strlen include/linux/fortify-string.h:210 [inline]
>> >  in4_pton+0xa3/0x3f0 net/core/utils.c:130
>> >  bond_option_arp_ip_targets_set+0xc2/0x910
>> > drivers/net/bonding/bond_options.c:1201
>> >  __bond_opt_set+0x2a4/0x1030 drivers/net/bonding/bond_options.c:767
>> >  __bond_opt_set_notify+0x48/0x150 drivers/net/bonding/bond_options.c:792
>> >  bond_opt_tryset_rtnl+0xda/0x160 drivers/net/bonding/bond_options.c:817
>> >  bonding_sysfs_store_option+0xa1/0x120 drivers/net/bonding/bond_sysfs.c:156
>> >  dev_attr_store+0x54/0x80 drivers/base/core.c:2366
>> >  sysfs_kf_write+0x114/0x170 fs/sysfs/file.c:136
>> >  kernfs_fop_write_iter+0x337/0x500 fs/kernfs/file.c:334
>> >  call_write_iter include/linux/fs.h:2020 [inline]
>> >  new_sync_write fs/read_write.c:491 [inline]
>> >  vfs_write+0x96a/0xd80 fs/read_write.c:584
>> >  ksys_write+0x122/0x250 fs/read_write.c:637
>> >  do_syscall_x64 arch/x86/entry/common.c:52 [inline]
>> >  do_syscall_64+0x40/0x110 arch/x86/entry/common.c:83
>> >  entry_SYSCALL_64_after_hwframe+0x63/0x6b
>> > ---[ end trace ]---
>> >
>> > Fix it by adding a check of string length before using it.
>> >
>> > Reported-by: Yue Sun <samsun1006219@gmail.com>
>>
>> Not sure if there is a need to add Reported-by yourself if you are the author.
>>
>> Also you need a Fixes tag if the patch target is net tree.
>
>Sorry for missing the Fixes tag, I will add it to patch. I am also not
>sure if I should add Reported-by here, since it's my first time to
>commit a patch for linux.

	The submitting-patches.rst file in Documentation/ isn't
explicit, but the intent seems to be that Reported-by is for a bug
report from a third party that isn't involved in creating the fix.  I
don't think you need it here, just a Signed-off-by.

>> > Signed-off-by: Yue Sun <samsun1006219@gmail.com>
>> > ---
>> >  drivers/net/bonding/bond_options.c | 3 ++-
>> >  1 file changed, 2 insertions(+), 1 deletion(-)
>> >
>> > diff --git a/drivers/net/bonding/bond_options.c
>> > b/drivers/net/bonding/bond_options.c
>> > index 4cdbc7e084f4..db8d99ca1de0 100644
>> > --- a/drivers/net/bonding/bond_options.c
>> > +++ b/drivers/net/bonding/bond_options.c
>> > @@ -1214,7 +1214,8 @@ static int bond_option_arp_ip_targets_set(struct
>> > bonding *bond,
>> >      __be32 target;
>> >
>> >      if (newval->string) {
>> > -        if (!in4_pton(newval->string+1, -1, (u8 *)&target, -1, NULL)) {
>> > +        if (!(strlen(newval->string)) ||
>> > +            !in4_pton(newval->string + 1, -1, (u8 *)&target, -1, NULL)) {
>> >              netdev_err(bond->dev, "invalid ARP target %pI4 specified\n",
>> >                     &target);
>>
>> Do we need to init target first if !(strlen(newval->string)) ?
>>
>Good question. I think we don't need to init target first, since in
>original logic in4_pton() also leave target untouched if any error
>occurs. If !(strlen(newval->string)), bond_option_arp_ip_targets_set()
>just ret and target is still untouched. But I am not sure about it.

	I think the original code is incorrect, as target will be
uninitialized if in4_pton() fails.  The netdev_err() message shouldn't
include target at all, it will never contain useful information.

	-J

>If anyone finds other problems, please let me know.
>
>Thanks,
>Yue
>> Thanks
>> Hangbin
>> >              return ret;
>> > --
>> > 2.34.1
>

---
	-Jay Vosburgh, jay.vosburgh@canonical.com
Sam Sun April 16, 2024, 6:42 a.m. UTC | #4
On Mon, Apr 15, 2024 at 11:43 PM Jay Vosburgh
<jay.vosburgh@canonical.com> wrote:
>         The submitting-patches.rst file in Documentation/ isn't
> explicit, but the intent seems to be that Reported-by is for a bug
> report from a third party that isn't involved in creating the fix.  I
> don't think you need it here, just a Signed-off-by.
>

Sure, I will change it in my next submission.

> >> > Signed-off-by: Yue Sun <samsun1006219@gmail.com>
> >> > ---
> >> >  drivers/net/bonding/bond_options.c | 3 ++-
> >> >  1 file changed, 2 insertions(+), 1 deletion(-)
> >> >
> >> > diff --git a/drivers/net/bonding/bond_options.c
> >> > b/drivers/net/bonding/bond_options.c
> >> > index 4cdbc7e084f4..db8d99ca1de0 100644
> >> > --- a/drivers/net/bonding/bond_options.c
> >> > +++ b/drivers/net/bonding/bond_options.c
> >> > @@ -1214,7 +1214,8 @@ static int bond_option_arp_ip_targets_set(struct
> >> > bonding *bond,
> >> >      __be32 target;
> >> >
> >> >      if (newval->string) {
> >> > -        if (!in4_pton(newval->string+1, -1, (u8 *)&target, -1, NULL)) {
> >> > +        if (!(strlen(newval->string)) ||
> >> > +            !in4_pton(newval->string + 1, -1, (u8 *)&target, -1, NULL)) {
> >> >              netdev_err(bond->dev, "invalid ARP target %pI4 specified\n",
> >> >                     &target);
> >>
> >> Do we need to init target first if !(strlen(newval->string)) ?
> >>
> >Good question. I think we don't need to init target first, since in
> >original logic in4_pton() also leave target untouched if any error
> >occurs. If !(strlen(newval->string)), bond_option_arp_ip_targets_set()
> >just ret and target is still untouched. But I am not sure about it.
>
>         I think the original code is incorrect, as target will be
> uninitialized if in4_pton() fails.  The netdev_err() message shouldn't
> include target at all, it will never contain useful information.
>
>         -J

Yes I think you are right. I will remove the target address in fmt
string in my next submission.

Best,
Yue
diff mbox series

Patch

diff --git a/drivers/net/bonding/bond_options.c
b/drivers/net/bonding/bond_options.c
index 4cdbc7e084f4..db8d99ca1de0 100644
--- a/drivers/net/bonding/bond_options.c
+++ b/drivers/net/bonding/bond_options.c
@@ -1214,7 +1214,8 @@  static int bond_option_arp_ip_targets_set(struct
bonding *bond,
     __be32 target;

     if (newval->string) {
-        if (!in4_pton(newval->string+1, -1, (u8 *)&target, -1, NULL)) {
+        if (!(strlen(newval->string)) ||
+            !in4_pton(newval->string + 1, -1, (u8 *)&target, -1, NULL)) {
             netdev_err(bond->dev, "invalid ARP target %pI4 specified\n",
                    &target);