Kuniyuki Iwashima ba632ad0ba bpf: Fix a data-race around bpf_jit_limit. ...

[ Upstream commit 0947ae1121 ]

While reading bpf_jit_limit, it can be changed concurrently via sysctl,
WRITE_ONCE() in __do_proc_doulongvec_minmax(). The size of bpf_jit_limit
is long, so we need to add a paired READ_ONCE() to avoid load-tearing.

Fixes: ede95a63b5 ("bpf: add bpf_jit_limit knob to restrict unpriv allocations")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20220823215804.2177-1-kuniyu@amazon.com
Signed-off-by: Sasha Levin <sashal@kernel.org>

2022-09-08 11:23:58 +02:00

71 KiB

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