Re: [Devel] [PATCH rh7] keys, user: Fix high order allocation in user_instantiate()
On 9/14/20 1:55 PM, Andrey Ryabinin wrote:
> Adding user key might trigger 4-order allocation which is unreliable
> in case of fragmented memory:
>
> [ cut here ]
> WARNING: CPU: 3 PID: 134927 at mm/page_alloc.c:3533
> __alloc_pages_nodemask+0x1b1/0x600
> order 4 >= 3, gfp 0x40d0
> Kernel panic - not syncing: panic_on_warn set ...
> CPU: 3 PID: 134927 Comm: add_key01 ve: 0 Kdump: loaded Tainted: G
> OE 3.10.0-1127.18.2.vz7.163.15 #1 163.15
> Hardware name: Virtuozzo KVM, BIOS 1.11.0-2.vz7.2 04/01/2014
> Call Trace:
> dump_stack+0x19/0x1b
> panic+0xe8/0x21f
> __warn+0xfa/0x100
> warn_slowpath_fmt+0x5f/0x80
> __alloc_pages_nodemask+0x1b1/0x600
> alloc_pages_current+0x98/0x110
> kmalloc_order+0x18/0x40
> kmalloc_order_trace+0x26/0xa0
> __kmalloc+0x281/0x2a0
> user_instantiate+0x47/0x90
> __key_instantiate_and_link+0x54/0x100
> key_create_or_update+0x398/0x490
> SyS_add_key+0x12c/0x220
> system_call_fastpath+0x25/0x2a
>
> Use kvmalloc() to avoid potential -ENOMEM due to fragmentation.
>
> https://jira.sw.ru/browse/PSBM-107794
> Signed-off-by: Andrey Ryabinin
> ---
> security/keys/user_defined.c | 11 +++
> 1 file changed, 7 insertions(+), 4 deletions(-)
>
> diff --git a/security/keys/user_defined.c b/security/keys/user_defined.c
> index bc8d3227dc4b..b13d70b69069 100644
> --- a/security/keys/user_defined.c
> +++ b/security/keys/user_defined.c
> @@ -9,6 +9,7 @@
> * 2 of the License, or (at your option) any later version.
> */
>
> +#include
> #include
> #include
> #include
> @@ -75,7 +76,7 @@ int user_instantiate(struct key *key, struct
> key_preparsed_payload *prep)
> goto error;
>
> ret = -ENOMEM;
> - upayload = kmalloc(sizeof(*upayload) + datalen, GFP_KERNEL);
> + upayload = kvmalloc(sizeof(*upayload) + datalen, GFP_KERNEL);
> if (!upayload)
> goto error;
>
> @@ -96,7 +97,8 @@ static void user_free_payload_rcu(struct rcu_head *head)
> struct user_key_payload *payload;
>
> payload = container_of(head, struct user_key_payload, rcu);
> - kzfree(payload);
> + memset(payload, 0, sizeof(*payload) + payload->datalen);
> + kvfree(payload);
> }
>
> /*
> @@ -115,7 +117,7 @@ int user_update(struct key *key, struct
> key_preparsed_payload *prep)
>
> /* construct a replacement payload */
> ret = -ENOMEM;
> - upayload = kmalloc(sizeof(*upayload) + datalen, GFP_KERNEL);
> + upayload = kvmalloc(sizeof(*upayload) + datalen, GFP_KERNEL);
> if (!upayload)
> goto error;
>
> @@ -182,7 +184,8 @@ void user_destroy(struct key *key)
> {
> struct user_key_payload *upayload = key->payload.data;
>
> - kzfree(upayload);
> + memset(upayload, 0, sizeof(*upayload) + upayload->datalen);
> + kvfree(upayload);
> }
>
> EXPORT_SYMBOL_GPL(user_destroy);
can you pls add #PSBM-107794 into subject line. This will keep track of
the issue
in the kernel changelog
___
Devel mailing list
Devel@openvz.org
https://lists.openvz.org/mailman/listinfo/devel
[Devel] [PATCH rh7] keys, user: Fix high order allocation in user_instantiate()
Adding user key might trigger 4-order allocation which is unreliable
in case of fragmented memory:
[ cut here ]
WARNING: CPU: 3 PID: 134927 at mm/page_alloc.c:3533
__alloc_pages_nodemask+0x1b1/0x600
order 4 >= 3, gfp 0x40d0
Kernel panic - not syncing: panic_on_warn set ...
CPU: 3 PID: 134927 Comm: add_key01 ve: 0 Kdump: loaded Tainted: G OE
3.10.0-1127.18.2.vz7.163.15 #1 163.15
Hardware name: Virtuozzo KVM, BIOS 1.11.0-2.vz7.2 04/01/2014
Call Trace:
dump_stack+0x19/0x1b
panic+0xe8/0x21f
__warn+0xfa/0x100
warn_slowpath_fmt+0x5f/0x80
__alloc_pages_nodemask+0x1b1/0x600
alloc_pages_current+0x98/0x110
kmalloc_order+0x18/0x40
kmalloc_order_trace+0x26/0xa0
__kmalloc+0x281/0x2a0
user_instantiate+0x47/0x90
__key_instantiate_and_link+0x54/0x100
key_create_or_update+0x398/0x490
SyS_add_key+0x12c/0x220
system_call_fastpath+0x25/0x2a
Use kvmalloc() to avoid potential -ENOMEM due to fragmentation.
https://jira.sw.ru/browse/PSBM-107794
Signed-off-by: Andrey Ryabinin
---
security/keys/user_defined.c | 11 +++
1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/security/keys/user_defined.c b/security/keys/user_defined.c
index bc8d3227dc4b..b13d70b69069 100644
--- a/security/keys/user_defined.c
+++ b/security/keys/user_defined.c
@@ -9,6 +9,7 @@
* 2 of the License, or (at your option) any later version.
*/
+#include
#include
#include
#include
@@ -75,7 +76,7 @@ int user_instantiate(struct key *key, struct
key_preparsed_payload *prep)
goto error;
ret = -ENOMEM;
- upayload = kmalloc(sizeof(*upayload) + datalen, GFP_KERNEL);
+ upayload = kvmalloc(sizeof(*upayload) + datalen, GFP_KERNEL);
if (!upayload)
goto error;
@@ -96,7 +97,8 @@ static void user_free_payload_rcu(struct rcu_head *head)
struct user_key_payload *payload;
payload = container_of(head, struct user_key_payload, rcu);
- kzfree(payload);
+ memset(payload, 0, sizeof(*payload) + payload->datalen);
+ kvfree(payload);
}
/*
@@ -115,7 +117,7 @@ int user_update(struct key *key, struct
key_preparsed_payload *prep)
/* construct a replacement payload */
ret = -ENOMEM;
- upayload = kmalloc(sizeof(*upayload) + datalen, GFP_KERNEL);
+ upayload = kvmalloc(sizeof(*upayload) + datalen, GFP_KERNEL);
if (!upayload)
goto error;
@@ -182,7 +184,8 @@ void user_destroy(struct key *key)
{
struct user_key_payload *upayload = key->payload.data;
- kzfree(upayload);
+ memset(upayload, 0, sizeof(*upayload) + upayload->datalen);
+ kvfree(upayload);
}
EXPORT_SYMBOL_GPL(user_destroy);
--
2.26.2
___
Devel mailing list
Devel@openvz.org
https://lists.openvz.org/mailman/listinfo/devel
