Re: [PATCH net 2/3] bpf: fix splat for illegal devmap percpu allocation
On 10/17/2017 07:55 AM, Daniel Borkmann wrote:
> It was reported that syzkaller was able to trigger a splat on
> devmap percpu allocation due to illegal/unsupported allocation
> request size passed to __alloc_percpu():
>
> [ 70.094249] illegal size (32776) or align (8) for percpu allocation
> [ 70.094256] [ cut here ]
> [ 70.094259] WARNING: CPU: 3 PID: 3451 at mm/percpu.c:1365
> pcpu_alloc+0x96/0x630
> [...]
> [ 70.094325] Call Trace:
> [ 70.094328] __alloc_percpu_gfp+0x12/0x20
> [ 70.094330] dev_map_alloc+0x134/0x1e0
> [ 70.094331] SyS_bpf+0x9bc/0x1610
> [ 70.094333] ? selinux_task_setrlimit+0x5a/0x60
> [ 70.094334] ? security_task_setrlimit+0x43/0x60
> [ 70.094336] entry_SYSCALL_64_fastpath+0x1a/0xa5
>
> This was due to too large max_entries for the map such that we
> surpassed the upper limit of PCPU_MIN_UNIT_SIZE. It's fine to
> fail naturally here, so switch to __alloc_percpu_gfp() and pass
> __GFP_NOWARN instead.
>
> Fixes: 11393cc9b9be ("xdp: Add batching support to redirect map")
> Reported-by: Mark Rutland
> Reported-by: Shankara Pailoor
> Reported-by: Richard Weinberger
> Signed-off-by: Daniel Borkmann
> Cc: John Fastabend
> ---
Thanks!
Acked-by: John Fastabend
Re: [PATCH net 2/3] bpf: fix splat for illegal devmap percpu allocation
On 10/17/2017 07:55 AM, Daniel Borkmann wrote:
> It was reported that syzkaller was able to trigger a splat on
> devmap percpu allocation due to illegal/unsupported allocation
> request size passed to __alloc_percpu():
>
> [ 70.094249] illegal size (32776) or align (8) for percpu allocation
> [ 70.094256] [ cut here ]
> [ 70.094259] WARNING: CPU: 3 PID: 3451 at mm/percpu.c:1365
> pcpu_alloc+0x96/0x630
> [...]
> [ 70.094325] Call Trace:
> [ 70.094328] __alloc_percpu_gfp+0x12/0x20
> [ 70.094330] dev_map_alloc+0x134/0x1e0
> [ 70.094331] SyS_bpf+0x9bc/0x1610
> [ 70.094333] ? selinux_task_setrlimit+0x5a/0x60
> [ 70.094334] ? security_task_setrlimit+0x43/0x60
> [ 70.094336] entry_SYSCALL_64_fastpath+0x1a/0xa5
>
> This was due to too large max_entries for the map such that we
> surpassed the upper limit of PCPU_MIN_UNIT_SIZE. It's fine to
> fail naturally here, so switch to __alloc_percpu_gfp() and pass
> __GFP_NOWARN instead.
>
> Fixes: 11393cc9b9be ("xdp: Add batching support to redirect map")
> Reported-by: Mark Rutland
> Reported-by: Shankara Pailoor
> Reported-by: Richard Weinberger
> Signed-off-by: Daniel Borkmann
> Cc: John Fastabend
> ---
Thanks!
Acked-by: John Fastabend
Re: [PATCH net 2/3] bpf: fix splat for illegal devmap percpu allocation
On Tue, Oct 17, 2017 at 04:55:53PM +0200, Daniel Borkmann wrote:
> It was reported that syzkaller was able to trigger a splat on
> devmap percpu allocation due to illegal/unsupported allocation
> request size passed to __alloc_percpu():
>
> [ 70.094249] illegal size (32776) or align (8) for percpu allocation
> [ 70.094256] [ cut here ]
> [ 70.094259] WARNING: CPU: 3 PID: 3451 at mm/percpu.c:1365
> pcpu_alloc+0x96/0x630
> [...]
> [ 70.094325] Call Trace:
> [ 70.094328] __alloc_percpu_gfp+0x12/0x20
> [ 70.094330] dev_map_alloc+0x134/0x1e0
> [ 70.094331] SyS_bpf+0x9bc/0x1610
> [ 70.094333] ? selinux_task_setrlimit+0x5a/0x60
> [ 70.094334] ? security_task_setrlimit+0x43/0x60
> [ 70.094336] entry_SYSCALL_64_fastpath+0x1a/0xa5
>
> This was due to too large max_entries for the map such that we
> surpassed the upper limit of PCPU_MIN_UNIT_SIZE. It's fine to
> fail naturally here, so switch to __alloc_percpu_gfp() and pass
> __GFP_NOWARN instead.
>
> Fixes: 11393cc9b9be ("xdp: Add batching support to redirect map")
> Reported-by: Mark Rutland
> Reported-by: Shankara Pailoor
> Reported-by: Richard Weinberger
> Signed-off-by: Daniel Borkmann
> Cc: John Fastabend
Acked-by: Alexei Starovoitov
Re: [PATCH net 2/3] bpf: fix splat for illegal devmap percpu allocation
On Tue, Oct 17, 2017 at 04:55:53PM +0200, Daniel Borkmann wrote:
> It was reported that syzkaller was able to trigger a splat on
> devmap percpu allocation due to illegal/unsupported allocation
> request size passed to __alloc_percpu():
>
> [ 70.094249] illegal size (32776) or align (8) for percpu allocation
> [ 70.094256] [ cut here ]
> [ 70.094259] WARNING: CPU: 3 PID: 3451 at mm/percpu.c:1365
> pcpu_alloc+0x96/0x630
> [...]
> [ 70.094325] Call Trace:
> [ 70.094328] __alloc_percpu_gfp+0x12/0x20
> [ 70.094330] dev_map_alloc+0x134/0x1e0
> [ 70.094331] SyS_bpf+0x9bc/0x1610
> [ 70.094333] ? selinux_task_setrlimit+0x5a/0x60
> [ 70.094334] ? security_task_setrlimit+0x43/0x60
> [ 70.094336] entry_SYSCALL_64_fastpath+0x1a/0xa5
>
> This was due to too large max_entries for the map such that we
> surpassed the upper limit of PCPU_MIN_UNIT_SIZE. It's fine to
> fail naturally here, so switch to __alloc_percpu_gfp() and pass
> __GFP_NOWARN instead.
>
> Fixes: 11393cc9b9be ("xdp: Add batching support to redirect map")
> Reported-by: Mark Rutland
> Reported-by: Shankara Pailoor
> Reported-by: Richard Weinberger
> Signed-off-by: Daniel Borkmann
> Cc: John Fastabend
Acked-by: Alexei Starovoitov
[PATCH net 2/3] bpf: fix splat for illegal devmap percpu allocation
It was reported that syzkaller was able to trigger a splat on
devmap percpu allocation due to illegal/unsupported allocation
request size passed to __alloc_percpu():
[ 70.094249] illegal size (32776) or align (8) for percpu allocation
[ 70.094256] [ cut here ]
[ 70.094259] WARNING: CPU: 3 PID: 3451 at mm/percpu.c:1365
pcpu_alloc+0x96/0x630
[...]
[ 70.094325] Call Trace:
[ 70.094328] __alloc_percpu_gfp+0x12/0x20
[ 70.094330] dev_map_alloc+0x134/0x1e0
[ 70.094331] SyS_bpf+0x9bc/0x1610
[ 70.094333] ? selinux_task_setrlimit+0x5a/0x60
[ 70.094334] ? security_task_setrlimit+0x43/0x60
[ 70.094336] entry_SYSCALL_64_fastpath+0x1a/0xa5
This was due to too large max_entries for the map such that we
surpassed the upper limit of PCPU_MIN_UNIT_SIZE. It's fine to
fail naturally here, so switch to __alloc_percpu_gfp() and pass
__GFP_NOWARN instead.
Fixes: 11393cc9b9be ("xdp: Add batching support to redirect map")
Reported-by: Mark Rutland
Reported-by: Shankara Pailoor
Reported-by: Richard Weinberger
Signed-off-by: Daniel Borkmann
Cc: John Fastabend
---
kernel/bpf/devmap.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c
index e093d9a..920428d 100644
--- a/kernel/bpf/devmap.c
+++ b/kernel/bpf/devmap.c
@@ -111,8 +111,9 @@ static struct bpf_map *dev_map_alloc(union bpf_attr *attr)
err = -ENOMEM;
/* A per cpu bitfield with a bit per possible net device */
- dtab->flush_needed = __alloc_percpu(dev_map_bitmap_size(attr),
- __alignof__(unsigned long));
+ dtab->flush_needed = __alloc_percpu_gfp(dev_map_bitmap_size(attr),
+ __alignof__(unsigned long),
+ GFP_KERNEL | __GFP_NOWARN);
if (!dtab->flush_needed)
goto free_dtab;
--
1.9.3
[PATCH net 2/3] bpf: fix splat for illegal devmap percpu allocation
It was reported that syzkaller was able to trigger a splat on
devmap percpu allocation due to illegal/unsupported allocation
request size passed to __alloc_percpu():
[ 70.094249] illegal size (32776) or align (8) for percpu allocation
[ 70.094256] [ cut here ]
[ 70.094259] WARNING: CPU: 3 PID: 3451 at mm/percpu.c:1365
pcpu_alloc+0x96/0x630
[...]
[ 70.094325] Call Trace:
[ 70.094328] __alloc_percpu_gfp+0x12/0x20
[ 70.094330] dev_map_alloc+0x134/0x1e0
[ 70.094331] SyS_bpf+0x9bc/0x1610
[ 70.094333] ? selinux_task_setrlimit+0x5a/0x60
[ 70.094334] ? security_task_setrlimit+0x43/0x60
[ 70.094336] entry_SYSCALL_64_fastpath+0x1a/0xa5
This was due to too large max_entries for the map such that we
surpassed the upper limit of PCPU_MIN_UNIT_SIZE. It's fine to
fail naturally here, so switch to __alloc_percpu_gfp() and pass
__GFP_NOWARN instead.
Fixes: 11393cc9b9be ("xdp: Add batching support to redirect map")
Reported-by: Mark Rutland
Reported-by: Shankara Pailoor
Reported-by: Richard Weinberger
Signed-off-by: Daniel Borkmann
Cc: John Fastabend
---
kernel/bpf/devmap.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c
index e093d9a..920428d 100644
--- a/kernel/bpf/devmap.c
+++ b/kernel/bpf/devmap.c
@@ -111,8 +111,9 @@ static struct bpf_map *dev_map_alloc(union bpf_attr *attr)
err = -ENOMEM;
/* A per cpu bitfield with a bit per possible net device */
- dtab->flush_needed = __alloc_percpu(dev_map_bitmap_size(attr),
- __alignof__(unsigned long));
+ dtab->flush_needed = __alloc_percpu_gfp(dev_map_bitmap_size(attr),
+ __alignof__(unsigned long),
+ GFP_KERNEL | __GFP_NOWARN);
if (!dtab->flush_needed)
goto free_dtab;
--
1.9.3
