From: Dongliang Mu <dzm91@hust.edu.cn>
To: Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Andrii Nakryiko <andrii@kernel.org>,
Martin KaFai Lau <kafai@fb.com>, Song Liu <songliubraving@fb.com>,
Yonghong Song <yhs@fb.com>,
John Fastabend <john.fastabend@gmail.com>,
KP Singh <kpsingh@kernel.org>
Cc: Dongliang Mu <mudongliangabcd@gmail.com>,
syzkaller <syzkaller@googlegroups.com>,
netdev@vger.kernel.org, bpf@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: [PATCH] bpf: cgroup: remove WARN_ON at bpf_cgroup_link_release
Date: Sun, 27 Feb 2022 21:40:08 +0800 [thread overview]
Message-ID: <20220227134009.1298488-1-dzm91@hust.edu.cn> (raw)
From: Dongliang Mu <mudongliangabcd@gmail.com>
When syzkaller injects fault into memory allocation at
bpf_prog_array_alloc, the kernel encounters a memory failure and
returns non-zero, thus leading to one WARN_ON at
bpf_cgroup_link_release. The stack trace is as follows:
__kmalloc+0x7e/0x3d0
bpf_prog_array_alloc+0x4f/0x60
compute_effective_progs+0x132/0x580
? __sanitizer_cov_trace_pc+0x1a/0x40
update_effective_progs+0x5e/0x260
__cgroup_bpf_detach+0x293/0x760
bpf_cgroup_link_release+0xad/0x400
bpf_link_free+0xca/0x190
bpf_link_put+0x161/0x1b0
bpf_link_release+0x33/0x40
__fput+0x286/0x9f0
Fix this by removing the WARN_ON for __cgroup_bpf_detach.
Reported-by: syzkaller <syzkaller@googlegroups.com>
Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com>
---
kernel/bpf/cgroup.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c
index 514b4681a90a..fdbdcee6c9fa 100644
--- a/kernel/bpf/cgroup.c
+++ b/kernel/bpf/cgroup.c
@@ -896,8 +896,8 @@ static void bpf_cgroup_link_release(struct bpf_link *link)
return;
}
- WARN_ON(__cgroup_bpf_detach(cg_link->cgroup, NULL, cg_link,
- cg_link->type));
+ __cgroup_bpf_detach(cg_link->cgroup, NULL, cg_link,
+ cg_link->type);
cg = cg_link->cgroup;
cg_link->cgroup = NULL;
--
2.25.1
next reply other threads:[~2022-02-27 13:41 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-27 13:40 Dongliang Mu [this message]
2022-03-01 16:28 ` [PATCH] bpf: cgroup: remove WARN_ON at bpf_cgroup_link_release Daniel Borkmann
2022-03-02 5:46 ` Dongliang Mu
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