tree 15da7ed745edf3ccc4c6cdea0dcb26d8802a87e0
parent 014536d85fcb2da7031b90ab7d8c7fbfb053fe29
author Jakub Sitnicki <jakub@cloudflare.com> 1716808807 +0200
committer Oleksandr Tymoshenko <ovt@google.com> 1719425420 +0000

bpf: Allow delete from sockmap/sockhash only if update is allowed

[ Upstream commit 98e948fb60d41447fd8d2d0c3b8637fc6b6dc26d ]

We have seen an influx of syzkaller reports where a BPF program attached to
a tracepoint triggers a locking rule violation by performing a map_delete
on a sockmap/sockhash.

We don't intend to support this artificial use scenario. Extend the
existing verifier allowed-program-type check for updating sockmap/sockhash
to also cover deleting from a map.

From now on only BPF programs which were previously allowed to update
sockmap/sockhash can delete from these map types.

BUG=b/349317653
TEST=presubmit
RELEASE_NOTE=Fixes CVE-2024-38662 in the Linux kernel

cos-patch: security-moderate
Fixes: ff9105993240 ("bpf, sockmap: Prevent lock inversion deadlock in map delete elem")
Reported-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Reported-by: syzbot+ec941d6e24f633a59172@syzkaller.appspotmail.com
Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: syzbot+ec941d6e24f633a59172@syzkaller.appspotmail.com
Acked-by: John Fastabend <john.fastabend@gmail.com>
Closes: https://syzkaller.appspot.com/bug?extid=ec941d6e24f633a59172
Link: https://lore.kernel.org/bpf/20240527-sockmap-verify-deletes-v1-1-944b372f2101@cloudflare.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Oleksandr Tymoshenko <ovt@google.com>
Change-Id: Ic2b02f7f5f64ab2af7f16b987c2befd270ed2d9d
Signed-off-by: Oleksandr Tymoshenko <ovt@google.com>
Reviewed-on: https://cos-review.googlesource.com/c/third_party/kernel/+/75054
Tested-by: Cusky Presubmit Bot <presubmit@cos-infra-prod.iam.gserviceaccount.com>
Reviewed-by: Arnav Kansal <rnv@google.com>
Reviewed-by: Kevin Berry <kpberry@google.com>