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 <[email protected]>
Signed-off-by: Yue Sun <[email protected]>
---
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);
return ret;
--
2.34.1
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 <[email protected]>
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 <[email protected]>
> ---
> 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
On Mon, Apr 15, 2024 at 3:32 PM Hangbin Liu <[email protected]> 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 <[email protected]>
>
> 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 <[email protected]>
> > ---
> > 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
Sam Sun <[email protected]> wrote:
>On Mon, Apr 15, 2024 at 3:32 PM Hangbin Liu <[email protected]> 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 <[email protected]>
>>
>> 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 <[email protected]>
>> > ---
>> > 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, [email protected]
On Mon, Apr 15, 2024 at 11:43 PM Jay Vosburgh
<[email protected]> 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 <[email protected]>
> >> > ---
> >> > 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