diff mbox series

net: ipv4: fix memory leak in netlbl_cipsov4_add_std

Message ID 20210608015158.3848878-1-sunnanyong@huawei.com (mailing list archive)
State New
Headers show
Series net: ipv4: fix memory leak in netlbl_cipsov4_add_std | expand

Commit Message

Reported by syzkaller:
BUG: memory leak
unreferenced object 0xffff888105df7000 (size 64):
comm "syz-executor842", pid 360, jiffies 4294824824 (age 22.546s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<00000000e67ed558>] kmalloc include/linux/slab.h:590 [inline]
[<00000000e67ed558>] kzalloc include/linux/slab.h:720 [inline]
[<00000000e67ed558>] netlbl_cipsov4_add_std net/netlabel/netlabel_cipso_v4.c:145 [inline]
[<00000000e67ed558>] netlbl_cipsov4_add+0x390/0x2340 net/netlabel/netlabel_cipso_v4.c:416
[<0000000006040154>] genl_family_rcv_msg_doit.isra.0+0x20e/0x320 net/netlink/genetlink.c:739
[<00000000204d7a1c>] genl_family_rcv_msg net/netlink/genetlink.c:783 [inline]
[<00000000204d7a1c>] genl_rcv_msg+0x2bf/0x4f0 net/netlink/genetlink.c:800
[<00000000c0d6a995>] netlink_rcv_skb+0x134/0x3d0 net/netlink/af_netlink.c:2504
[<00000000d78b9d2c>] genl_rcv+0x24/0x40 net/netlink/genetlink.c:811
[<000000009733081b>] netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline]
[<000000009733081b>] netlink_unicast+0x4a0/0x6a0 net/netlink/af_netlink.c:1340
[<00000000d5fd43b8>] netlink_sendmsg+0x789/0xc70 net/netlink/af_netlink.c:1929
[<000000000a2d1e40>] sock_sendmsg_nosec net/socket.c:654 [inline]
[<000000000a2d1e40>] sock_sendmsg+0x139/0x170 net/socket.c:674
[<00000000321d1969>] ____sys_sendmsg+0x658/0x7d0 net/socket.c:2350
[<00000000964e16bc>] ___sys_sendmsg+0xf8/0x170 net/socket.c:2404
[<000000001615e288>] __sys_sendmsg+0xd3/0x190 net/socket.c:2433
[<000000004ee8b6a5>] do_syscall_64+0x37/0x90 arch/x86/entry/common.c:47
[<00000000171c7cee>] entry_SYSCALL_64_after_hwframe+0x44/0xae

The memory of doi_def->map.std pointing is allocated in
netlbl_cipsov4_add_std, but no place has freed it. It should be
freed in cipso_v4_doi_free which frees the cipso DOI resource.

Fixes: 96cb8e3313c7a ("[NetLabel]: CIPSOv4 and Unlabeled packet integration")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Nanyong Sun <sunnanyong@huawei.com>
---
 net/ipv4/cipso_ipv4.c | 1 +
 1 file changed, 1 insertion(+)

Comments

Paul Moore June 8, 2021, 1:53 a.m. UTC | #1
On Mon, Jun 7, 2021 at 9:19 PM Nanyong Sun <sunnanyong@huawei.com> wrote:
>
> Reported by syzkaller:
> BUG: memory leak
> unreferenced object 0xffff888105df7000 (size 64):
> comm "syz-executor842", pid 360, jiffies 4294824824 (age 22.546s)
> hex dump (first 32 bytes):
> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
> backtrace:
> [<00000000e67ed558>] kmalloc include/linux/slab.h:590 [inline]
> [<00000000e67ed558>] kzalloc include/linux/slab.h:720 [inline]
> [<00000000e67ed558>] netlbl_cipsov4_add_std net/netlabel/netlabel_cipso_v4.c:145 [inline]
> [<00000000e67ed558>] netlbl_cipsov4_add+0x390/0x2340 net/netlabel/netlabel_cipso_v4.c:416
> [<0000000006040154>] genl_family_rcv_msg_doit.isra.0+0x20e/0x320 net/netlink/genetlink.c:739
> [<00000000204d7a1c>] genl_family_rcv_msg net/netlink/genetlink.c:783 [inline]
> [<00000000204d7a1c>] genl_rcv_msg+0x2bf/0x4f0 net/netlink/genetlink.c:800
> [<00000000c0d6a995>] netlink_rcv_skb+0x134/0x3d0 net/netlink/af_netlink.c:2504
> [<00000000d78b9d2c>] genl_rcv+0x24/0x40 net/netlink/genetlink.c:811
> [<000000009733081b>] netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline]
> [<000000009733081b>] netlink_unicast+0x4a0/0x6a0 net/netlink/af_netlink.c:1340
> [<00000000d5fd43b8>] netlink_sendmsg+0x789/0xc70 net/netlink/af_netlink.c:1929
> [<000000000a2d1e40>] sock_sendmsg_nosec net/socket.c:654 [inline]
> [<000000000a2d1e40>] sock_sendmsg+0x139/0x170 net/socket.c:674
> [<00000000321d1969>] ____sys_sendmsg+0x658/0x7d0 net/socket.c:2350
> [<00000000964e16bc>] ___sys_sendmsg+0xf8/0x170 net/socket.c:2404
> [<000000001615e288>] __sys_sendmsg+0xd3/0x190 net/socket.c:2433
> [<000000004ee8b6a5>] do_syscall_64+0x37/0x90 arch/x86/entry/common.c:47
> [<00000000171c7cee>] entry_SYSCALL_64_after_hwframe+0x44/0xae
>
> The memory of doi_def->map.std pointing is allocated in
> netlbl_cipsov4_add_std, but no place has freed it. It should be
> freed in cipso_v4_doi_free which frees the cipso DOI resource.
>
> Fixes: 96cb8e3313c7a ("[NetLabel]: CIPSOv4 and Unlabeled packet integration")
> Reported-by: Hulk Robot <hulkci@huawei.com>
> Signed-off-by: Nanyong Sun <sunnanyong@huawei.com>
> ---
>  net/ipv4/cipso_ipv4.c | 1 +
>  1 file changed, 1 insertion(+)

Nice catch, thanks for fixing this.

Acked-by: Paul Moore <paul@paul-moore.com>

> diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c
> index d6e3a92841e3..099259fc826a 100644
> --- a/net/ipv4/cipso_ipv4.c
> +++ b/net/ipv4/cipso_ipv4.c
> @@ -471,6 +471,7 @@ void cipso_v4_doi_free(struct cipso_v4_doi *doi_def)
>                 kfree(doi_def->map.std->lvl.local);
>                 kfree(doi_def->map.std->cat.cipso);
>                 kfree(doi_def->map.std->cat.local);
> +               kfree(doi_def->map.std);
>                 break;
>         }
>         kfree(doi_def);
> --
> 2.18.0.huawei.25
Dongliang Mu June 8, 2021, 2:30 a.m. UTC | #2
On Tue, Jun 8, 2021 at 9:57 AM Paul Moore <paul@paul-moore.com> wrote:
>
> On Mon, Jun 7, 2021 at 9:19 PM Nanyong Sun <sunnanyong@huawei.com> wrote:
> >
> > Reported by syzkaller:
> > BUG: memory leak
> > unreferenced object 0xffff888105df7000 (size 64):
> > comm "syz-executor842", pid 360, jiffies 4294824824 (age 22.546s)
> > hex dump (first 32 bytes):
> > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
> > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
> > backtrace:
> > [<00000000e67ed558>] kmalloc include/linux/slab.h:590 [inline]
> > [<00000000e67ed558>] kzalloc include/linux/slab.h:720 [inline]
> > [<00000000e67ed558>] netlbl_cipsov4_add_std net/netlabel/netlabel_cipso_v4.c:145 [inline]
> > [<00000000e67ed558>] netlbl_cipsov4_add+0x390/0x2340 net/netlabel/netlabel_cipso_v4.c:416
> > [<0000000006040154>] genl_family_rcv_msg_doit.isra.0+0x20e/0x320 net/netlink/genetlink.c:739
> > [<00000000204d7a1c>] genl_family_rcv_msg net/netlink/genetlink.c:783 [inline]
> > [<00000000204d7a1c>] genl_rcv_msg+0x2bf/0x4f0 net/netlink/genetlink.c:800
> > [<00000000c0d6a995>] netlink_rcv_skb+0x134/0x3d0 net/netlink/af_netlink.c:2504
> > [<00000000d78b9d2c>] genl_rcv+0x24/0x40 net/netlink/genetlink.c:811
> > [<000000009733081b>] netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline]
> > [<000000009733081b>] netlink_unicast+0x4a0/0x6a0 net/netlink/af_netlink.c:1340
> > [<00000000d5fd43b8>] netlink_sendmsg+0x789/0xc70 net/netlink/af_netlink.c:1929
> > [<000000000a2d1e40>] sock_sendmsg_nosec net/socket.c:654 [inline]
> > [<000000000a2d1e40>] sock_sendmsg+0x139/0x170 net/socket.c:674
> > [<00000000321d1969>] ____sys_sendmsg+0x658/0x7d0 net/socket.c:2350
> > [<00000000964e16bc>] ___sys_sendmsg+0xf8/0x170 net/socket.c:2404
> > [<000000001615e288>] __sys_sendmsg+0xd3/0x190 net/socket.c:2433
> > [<000000004ee8b6a5>] do_syscall_64+0x37/0x90 arch/x86/entry/common.c:47
> > [<00000000171c7cee>] entry_SYSCALL_64_after_hwframe+0x44/0xae
> >
> > The memory of doi_def->map.std pointing is allocated in
> > netlbl_cipsov4_add_std, but no place has freed it. It should be
> > freed in cipso_v4_doi_free which frees the cipso DOI resource.
> >
> > Fixes: 96cb8e3313c7a ("[NetLabel]: CIPSOv4 and Unlabeled packet integration")
> > Reported-by: Hulk Robot <hulkci@huawei.com>
> > Signed-off-by: Nanyong Sun <sunnanyong@huawei.com>
> > ---
> >  net/ipv4/cipso_ipv4.c | 1 +
> >  1 file changed, 1 insertion(+)
>
> Nice catch, thanks for fixing this.
>
> Acked-by: Paul Moore <paul@paul-moore.com>
>
> > diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c
> > index d6e3a92841e3..099259fc826a 100644
> > --- a/net/ipv4/cipso_ipv4.c
> > +++ b/net/ipv4/cipso_ipv4.c
> > @@ -471,6 +471,7 @@ void cipso_v4_doi_free(struct cipso_v4_doi *doi_def)
> >                 kfree(doi_def->map.std->lvl.local);
> >                 kfree(doi_def->map.std->cat.cipso);
> >                 kfree(doi_def->map.std->cat.local);
> > +               kfree(doi_def->map.std);
> >                 break;
> >         }
> >         kfree(doi_def);

Hi kernel developers,

I doubt this patch may cause invalid free in other functions where
map.std is not allocated or initialized, such as
netlbl_cipsov4_add_local, netlbl_cipsov4_add_pass.

Take netlbl_cipsov4_add_pass as an example, any failure after the
doi_def allocation failure will go to cipso_v4_doi_free, and free
doi_def->map.std.

static int netlbl_cipsov4_add_pass(struct genl_info *info,
  struct netlbl_audit *audit_info)
{
int ret_val;
struct cipso_v4_doi *doi_def = NULL;

if (!info->attrs[NLBL_CIPSOV4_A_TAGLST])
return -EINVAL;

doi_def = kmalloc(sizeof(*doi_def), GFP_KERNEL);
if (doi_def == NULL)
return -ENOMEM;
doi_def->type = CIPSO_V4_MAP_PASS;

ret_val = netlbl_cipsov4_add_common(info, doi_def);
if (ret_val != 0)
goto add_pass_failure;

ret_val = cipso_v4_doi_add(doi_def, audit_info);
if (ret_val != 0)
goto add_pass_failure;
return 0;

add_pass_failure:
cipso_v4_doi_free(doi_def);
return ret_val;
}

[1] https://elixir.bootlin.com/linux/latest/source/net/netlabel/netlabel_cipso_v4.c#L326

> > --
> > 2.18.0.huawei.25
>
> --
> paul moore
> www.paul-moore.com
Dongliang Mu June 8, 2021, 2:56 a.m. UTC | #3
On Tue, Jun 8, 2021 at 10:30 AM Dongliang Mu <mudongliangabcd@gmail.com> wrote:
>
> On Tue, Jun 8, 2021 at 9:57 AM Paul Moore <paul@paul-moore.com> wrote:
> >
> > On Mon, Jun 7, 2021 at 9:19 PM Nanyong Sun <sunnanyong@huawei.com> wrote:
> > >
> > > Reported by syzkaller:
> > > BUG: memory leak
> > > unreferenced object 0xffff888105df7000 (size 64):
> > > comm "syz-executor842", pid 360, jiffies 4294824824 (age 22.546s)
> > > hex dump (first 32 bytes):
> > > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
> > > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
> > > backtrace:
> > > [<00000000e67ed558>] kmalloc include/linux/slab.h:590 [inline]
> > > [<00000000e67ed558>] kzalloc include/linux/slab.h:720 [inline]
> > > [<00000000e67ed558>] netlbl_cipsov4_add_std net/netlabel/netlabel_cipso_v4.c:145 [inline]
> > > [<00000000e67ed558>] netlbl_cipsov4_add+0x390/0x2340 net/netlabel/netlabel_cipso_v4.c:416
> > > [<0000000006040154>] genl_family_rcv_msg_doit.isra.0+0x20e/0x320 net/netlink/genetlink.c:739
> > > [<00000000204d7a1c>] genl_family_rcv_msg net/netlink/genetlink.c:783 [inline]
> > > [<00000000204d7a1c>] genl_rcv_msg+0x2bf/0x4f0 net/netlink/genetlink.c:800
> > > [<00000000c0d6a995>] netlink_rcv_skb+0x134/0x3d0 net/netlink/af_netlink.c:2504
> > > [<00000000d78b9d2c>] genl_rcv+0x24/0x40 net/netlink/genetlink.c:811
> > > [<000000009733081b>] netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline]
> > > [<000000009733081b>] netlink_unicast+0x4a0/0x6a0 net/netlink/af_netlink.c:1340
> > > [<00000000d5fd43b8>] netlink_sendmsg+0x789/0xc70 net/netlink/af_netlink.c:1929
> > > [<000000000a2d1e40>] sock_sendmsg_nosec net/socket.c:654 [inline]
> > > [<000000000a2d1e40>] sock_sendmsg+0x139/0x170 net/socket.c:674
> > > [<00000000321d1969>] ____sys_sendmsg+0x658/0x7d0 net/socket.c:2350
> > > [<00000000964e16bc>] ___sys_sendmsg+0xf8/0x170 net/socket.c:2404
> > > [<000000001615e288>] __sys_sendmsg+0xd3/0x190 net/socket.c:2433
> > > [<000000004ee8b6a5>] do_syscall_64+0x37/0x90 arch/x86/entry/common.c:47
> > > [<00000000171c7cee>] entry_SYSCALL_64_after_hwframe+0x44/0xae
> > >
> > > The memory of doi_def->map.std pointing is allocated in
> > > netlbl_cipsov4_add_std, but no place has freed it. It should be
> > > freed in cipso_v4_doi_free which frees the cipso DOI resource.
> > >
> > > Fixes: 96cb8e3313c7a ("[NetLabel]: CIPSOv4 and Unlabeled packet integration")
> > > Reported-by: Hulk Robot <hulkci@huawei.com>
> > > Signed-off-by: Nanyong Sun <sunnanyong@huawei.com>
> > > ---
> > >  net/ipv4/cipso_ipv4.c | 1 +
> > >  1 file changed, 1 insertion(+)
> >
> > Nice catch, thanks for fixing this.
> >
> > Acked-by: Paul Moore <paul@paul-moore.com>
> >
> > > diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c
> > > index d6e3a92841e3..099259fc826a 100644
> > > --- a/net/ipv4/cipso_ipv4.c
> > > +++ b/net/ipv4/cipso_ipv4.c
> > > @@ -471,6 +471,7 @@ void cipso_v4_doi_free(struct cipso_v4_doi *doi_def)
> > >                 kfree(doi_def->map.std->lvl.local);
> > >                 kfree(doi_def->map.std->cat.cipso);
> > >                 kfree(doi_def->map.std->cat.local);
> > > +               kfree(doi_def->map.std);
> > >                 break;
> > >         }
> > >         kfree(doi_def);
>
> Hi kernel developers,
>
> I doubt this patch may cause invalid free in other functions where
> map.std is not allocated or initialized, such as
> netlbl_cipsov4_add_local, netlbl_cipsov4_add_pass.
>
> Take netlbl_cipsov4_add_pass as an example, any failure after the
> doi_def allocation failure will go to cipso_v4_doi_free, and free
> doi_def->map.std.

Sorry for the false alarm.

The new added kfree(doi_def->map.std) is under the condition - case
CIPSO_V4_MAP_TRANS. So there will be not invalid free. Sorry about
this.

>
> static int netlbl_cipsov4_add_pass(struct genl_info *info,
>   struct netlbl_audit *audit_info)
> {
> int ret_val;
> struct cipso_v4_doi *doi_def = NULL;
>
> if (!info->attrs[NLBL_CIPSOV4_A_TAGLST])
> return -EINVAL;
>
> doi_def = kmalloc(sizeof(*doi_def), GFP_KERNEL);
> if (doi_def == NULL)
> return -ENOMEM;
> doi_def->type = CIPSO_V4_MAP_PASS;
>
> ret_val = netlbl_cipsov4_add_common(info, doi_def);
> if (ret_val != 0)
> goto add_pass_failure;
>
> ret_val = cipso_v4_doi_add(doi_def, audit_info);
> if (ret_val != 0)
> goto add_pass_failure;
> return 0;
>
> add_pass_failure:
> cipso_v4_doi_free(doi_def);
> return ret_val;
> }
>
> [1] https://elixir.bootlin.com/linux/latest/source/net/netlabel/netlabel_cipso_v4.c#L326
>
> > > --
> > > 2.18.0.huawei.25
> >
> > --
> > paul moore
> > www.paul-moore.com
Paul Moore June 8, 2021, 2:56 a.m. UTC | #4
On Mon, Jun 7, 2021 at 10:31 PM Dongliang Mu <mudongliangabcd@gmail.com> wrote:
> On Tue, Jun 8, 2021 at 9:57 AM Paul Moore <paul@paul-moore.com> wrote:
> > On Mon, Jun 7, 2021 at 9:19 PM Nanyong Sun <sunnanyong@huawei.com> wrote:
> > >
> > > Reported by syzkaller:
> > > BUG: memory leak
> > > unreferenced object 0xffff888105df7000 (size 64):
> > > comm "syz-executor842", pid 360, jiffies 4294824824 (age 22.546s)
> > > hex dump (first 32 bytes):
> > > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
> > > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
> > > backtrace:
> > > [<00000000e67ed558>] kmalloc include/linux/slab.h:590 [inline]
> > > [<00000000e67ed558>] kzalloc include/linux/slab.h:720 [inline]
> > > [<00000000e67ed558>] netlbl_cipsov4_add_std net/netlabel/netlabel_cipso_v4.c:145 [inline]
> > > [<00000000e67ed558>] netlbl_cipsov4_add+0x390/0x2340 net/netlabel/netlabel_cipso_v4.c:416
> > > [<0000000006040154>] genl_family_rcv_msg_doit.isra.0+0x20e/0x320 net/netlink/genetlink.c:739
> > > [<00000000204d7a1c>] genl_family_rcv_msg net/netlink/genetlink.c:783 [inline]
> > > [<00000000204d7a1c>] genl_rcv_msg+0x2bf/0x4f0 net/netlink/genetlink.c:800
> > > [<00000000c0d6a995>] netlink_rcv_skb+0x134/0x3d0 net/netlink/af_netlink.c:2504
> > > [<00000000d78b9d2c>] genl_rcv+0x24/0x40 net/netlink/genetlink.c:811
> > > [<000000009733081b>] netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline]
> > > [<000000009733081b>] netlink_unicast+0x4a0/0x6a0 net/netlink/af_netlink.c:1340
> > > [<00000000d5fd43b8>] netlink_sendmsg+0x789/0xc70 net/netlink/af_netlink.c:1929
> > > [<000000000a2d1e40>] sock_sendmsg_nosec net/socket.c:654 [inline]
> > > [<000000000a2d1e40>] sock_sendmsg+0x139/0x170 net/socket.c:674
> > > [<00000000321d1969>] ____sys_sendmsg+0x658/0x7d0 net/socket.c:2350
> > > [<00000000964e16bc>] ___sys_sendmsg+0xf8/0x170 net/socket.c:2404
> > > [<000000001615e288>] __sys_sendmsg+0xd3/0x190 net/socket.c:2433
> > > [<000000004ee8b6a5>] do_syscall_64+0x37/0x90 arch/x86/entry/common.c:47
> > > [<00000000171c7cee>] entry_SYSCALL_64_after_hwframe+0x44/0xae
> > >
> > > The memory of doi_def->map.std pointing is allocated in
> > > netlbl_cipsov4_add_std, but no place has freed it. It should be
> > > freed in cipso_v4_doi_free which frees the cipso DOI resource.
> > >
> > > Fixes: 96cb8e3313c7a ("[NetLabel]: CIPSOv4 and Unlabeled packet integration")
> > > Reported-by: Hulk Robot <hulkci@huawei.com>
> > > Signed-off-by: Nanyong Sun <sunnanyong@huawei.com>
> > > ---
> > >  net/ipv4/cipso_ipv4.c | 1 +
> > >  1 file changed, 1 insertion(+)
> >
> > Nice catch, thanks for fixing this.
> >
> > Acked-by: Paul Moore <paul@paul-moore.com>
> >
> > > diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c
> > > index d6e3a92841e3..099259fc826a 100644
> > > --- a/net/ipv4/cipso_ipv4.c
> > > +++ b/net/ipv4/cipso_ipv4.c
> > > @@ -471,6 +471,7 @@ void cipso_v4_doi_free(struct cipso_v4_doi *doi_def)
> > >                 kfree(doi_def->map.std->lvl.local);
> > >                 kfree(doi_def->map.std->cat.cipso);
> > >                 kfree(doi_def->map.std->cat.local);
> > > +               kfree(doi_def->map.std);
> > >                 break;
> > >         }
> > >         kfree(doi_def);
>
> Hi kernel developers,
>
> I doubt this patch may cause invalid free in other functions where
> map.std is not allocated or initialized, such as
> netlbl_cipsov4_add_local, netlbl_cipsov4_add_pass.

It isn't perfectly clear to me if you are implying there is a problem
with the proposed patch or not, so I thought it might help to try and
add some clarity.

The patch above frees the cipso_v4_doi->map.std field, which is only
valid when the cipso_v4_doi->type field is equal to
CIPSO_V4_MAP_TRANS.  This is why the cipso_v4_doi_free() function
checks the type field before freeing the cipso_v4_doi->map related
fields, and why the proposed patch places the new kfree() inside that
conditional code block.

If we look at netlalbel_cipsov4_add_pass() we see that the first thing
it does after allocating a cipso_v4_doi struct is to set the type
field to CIPSO_V4_MAP_PASS.  Any calls to cipso_v4_doi_free after this
point will not end up calling the proposed kfree() addition due to the
cipso_v4_doi->type check.

We see something very similar with netlbl_cipsov4_add_local(),
although in this case the type field is set to CIPSO_V4_MAP_LOCAL.
This type value will also not trigger the proposed kfree().

If you are aware of any other potential issues with this patch please
do let us know, but from what I can see, the two concerns you
presented here are not problems with the current or proposed code.
patchwork-bot+netdevbpf@kernel.org June 8, 2021, 6:40 p.m. UTC | #5
Hello:

This patch was applied to netdev/net.git (refs/heads/master):

On Tue, 8 Jun 2021 09:51:58 +0800 you wrote:
> Reported by syzkaller:
> BUG: memory leak
> unreferenced object 0xffff888105df7000 (size 64):
> comm "syz-executor842", pid 360, jiffies 4294824824 (age 22.546s)
> hex dump (first 32 bytes):
> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
> backtrace:
> [<00000000e67ed558>] kmalloc include/linux/slab.h:590 [inline]
> [<00000000e67ed558>] kzalloc include/linux/slab.h:720 [inline]
> [<00000000e67ed558>] netlbl_cipsov4_add_std net/netlabel/netlabel_cipso_v4.c:145 [inline]
> [<00000000e67ed558>] netlbl_cipsov4_add+0x390/0x2340 net/netlabel/netlabel_cipso_v4.c:416
> [<0000000006040154>] genl_family_rcv_msg_doit.isra.0+0x20e/0x320 net/netlink/genetlink.c:739
> [<00000000204d7a1c>] genl_family_rcv_msg net/netlink/genetlink.c:783 [inline]
> [<00000000204d7a1c>] genl_rcv_msg+0x2bf/0x4f0 net/netlink/genetlink.c:800
> [<00000000c0d6a995>] netlink_rcv_skb+0x134/0x3d0 net/netlink/af_netlink.c:2504
> [<00000000d78b9d2c>] genl_rcv+0x24/0x40 net/netlink/genetlink.c:811
> [<000000009733081b>] netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline]
> [<000000009733081b>] netlink_unicast+0x4a0/0x6a0 net/netlink/af_netlink.c:1340
> [<00000000d5fd43b8>] netlink_sendmsg+0x789/0xc70 net/netlink/af_netlink.c:1929
> [<000000000a2d1e40>] sock_sendmsg_nosec net/socket.c:654 [inline]
> [<000000000a2d1e40>] sock_sendmsg+0x139/0x170 net/socket.c:674
> [<00000000321d1969>] ____sys_sendmsg+0x658/0x7d0 net/socket.c:2350
> [<00000000964e16bc>] ___sys_sendmsg+0xf8/0x170 net/socket.c:2404
> [<000000001615e288>] __sys_sendmsg+0xd3/0x190 net/socket.c:2433
> [<000000004ee8b6a5>] do_syscall_64+0x37/0x90 arch/x86/entry/common.c:47
> [<00000000171c7cee>] entry_SYSCALL_64_after_hwframe+0x44/0xae
> 
> [...]

Here is the summary with links:
  - net: ipv4: fix memory leak in netlbl_cipsov4_add_std
    https://git.kernel.org/netdev/net/c/d612c3f3fae2

You are awesome, thank you!
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diff mbox series

Patch

diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c
index d6e3a92841e3..099259fc826a 100644
--- a/net/ipv4/cipso_ipv4.c
+++ b/net/ipv4/cipso_ipv4.c
@@ -471,6 +471,7 @@  void cipso_v4_doi_free(struct cipso_v4_doi *doi_def)
 		kfree(doi_def->map.std->lvl.local);
 		kfree(doi_def->map.std->cat.cipso);
 		kfree(doi_def->map.std->cat.local);
+		kfree(doi_def->map.std);
 		break;
 	}
 	kfree(doi_def);