* [PATCH AUTOSEL 5.0 22/34] tools: bpftool: fix infinite loop in map create
[not found] <20190516113932.8348-1-sashal@kernel.org>
@ 2019-05-16 11:39 ` Sasha Levin
2019-05-16 11:39 ` [PATCH AUTOSEL 5.0 23/34] bpf: Fix preempt_enable_no_resched() abuse Sasha Levin
1 sibling, 0 replies; 2+ messages in thread
From: Sasha Levin @ 2019-05-16 11:39 UTC (permalink / raw)
To: linux-kernel, stable
Cc: Alban Crequy, Quentin Monnet, Song Liu, Jakub Kicinski,
Daniel Borkmann, Alexei Starovoitov, Sasha Levin, netdev, bpf
From: Alban Crequy <alban@kinvolk.io>
[ Upstream commit 8694d8c1f82cccec9380e0d3720b84eee315dfb7 ]
"bpftool map create" has an infinite loop on "while (argc)". The error
case is missing.
Symptoms: when forgetting to type the keyword 'type' in front of 'hash':
$ sudo bpftool map create /sys/fs/bpf/dir/foobar hash key 8 value 8 entries 128
(infinite loop, taking all the CPU)
^C
After the patch:
$ sudo bpftool map create /sys/fs/bpf/dir/foobar hash key 8 value 8 entries 128
Error: unknown arg hash
Fixes: 0b592b5a01be ("tools: bpftool: add map create command")
Signed-off-by: Alban Crequy <alban@kinvolk.io>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Acked-by: Song Liu <songliubraving@fb.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
tools/bpf/bpftool/map.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/tools/bpf/bpftool/map.c b/tools/bpf/bpftool/map.c
index 1ef1ee2280a28..227766d9f43b1 100644
--- a/tools/bpf/bpftool/map.c
+++ b/tools/bpf/bpftool/map.c
@@ -1111,6 +1111,9 @@ static int do_create(int argc, char **argv)
return -1;
}
NEXT_ARG();
+ } else {
+ p_err("unknown arg %s", *argv);
+ return -1;
}
}
--
2.20.1
^ permalink raw reply related [flat|nested] 2+ messages in thread* [PATCH AUTOSEL 5.0 23/34] bpf: Fix preempt_enable_no_resched() abuse
[not found] <20190516113932.8348-1-sashal@kernel.org>
2019-05-16 11:39 ` [PATCH AUTOSEL 5.0 22/34] tools: bpftool: fix infinite loop in map create Sasha Levin
@ 2019-05-16 11:39 ` Sasha Levin
1 sibling, 0 replies; 2+ messages in thread
From: Sasha Levin @ 2019-05-16 11:39 UTC (permalink / raw)
To: linux-kernel, stable
Cc: Peter Zijlstra, Roman Gushchin, Alexei Starovoitov,
Daniel Borkmann, Sasha Levin, netdev, bpf
From: Peter Zijlstra <peterz@infradead.org>
[ Upstream commit 0edd6b64d1939e9e9168ff27947995bb7751db5d ]
Unless the very next line is schedule(), or implies it, one must not use
preempt_enable_no_resched(). It can cause a preemption to go missing and
thereby cause arbitrary delays, breaking the PREEMPT=y invariant.
Cc: Roman Gushchin <guro@fb.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
include/linux/bpf.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index e734f163bd0b9..1fbd7672e4b37 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -455,7 +455,7 @@ int bpf_prog_array_copy(struct bpf_prog_array __rcu *old_array,
} \
_out: \
rcu_read_unlock(); \
- preempt_enable_no_resched(); \
+ preempt_enable(); \
_ret; \
})
--
2.20.1
^ permalink raw reply related [flat|nested] 2+ messages in thread