diff options
| author | Daniel Borkmann <daniel@iogearbox.net> | 2018-02-14 15:31:00 +0100 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2018-02-14 08:59:37 -0800 |
| commit | 9c481b908b011398b1491752271cd1e2c9ad5758 (patch) | |
| tree | 34373d78f0fab592edde75fec9631b43a56897ad /kernel/bpf/core.c | |
| parent | 7fc17e909edfb9bf421ee04e981d3d474175c7c7 (diff) | |
| download | linux-9c481b908b011398b1491752271cd1e2c9ad5758.tar.gz | |
bpf: fix bpf_prog_array_copy_to_user warning from perf event prog query
syzkaller tried to perform a prog query in perf_event_query_prog_array()
where struct perf_event_query_bpf had an ids_len of 1,073,741,353 and
thus causing a warning due to failed kcalloc() allocation out of the
bpf_prog_array_copy_to_user() helper. Given we cannot attach more than
64 programs to a perf event, there's no point in allowing huge ids_len.
Therefore, allow a buffer that would fix the maximum number of ids and
also add a __GFP_NOWARN to the temporary ids buffer.
Fixes: f371b304f12e ("bpf/tracing: allow user space to query prog array on the same tp")
Fixes: 0911287ce32b ("bpf: fix bpf_prog_array_copy_to_user() issues")
Reported-by: syzbot+cab5816b0edbabf598b3@syzkaller.appspotmail.com
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'kernel/bpf/core.c')
| -rw-r--r-- | kernel/bpf/core.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index 29ca9208dcfa..d315b393abdd 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -1590,7 +1590,7 @@ int bpf_prog_array_copy_to_user(struct bpf_prog_array __rcu *progs, * so always copy 'cnt' prog_ids to the user. * In a rare race the user will see zero prog_ids */ - ids = kcalloc(cnt, sizeof(u32), GFP_USER); + ids = kcalloc(cnt, sizeof(u32), GFP_USER | __GFP_NOWARN); if (!ids) return -ENOMEM; rcu_read_lock(); |