On Tue, May 21, 2024 at 11:18:26AM +0100, Ignat Korchagin wrote:
From: Jiri Olsa jolsa@kernel.org
commit 117211aa739a926e6555cfea883be84bee6f1695 upstream.
Pengfei Xu reported [1] Syzkaller/KASAN issue found in bpf_link_show_fdinfo.
The reason is missing BPF_LINK_TYPE invocation for uprobe multi link and for several other links, adding that.
[1] https://lore.kernel.org/bpf/ZXptoKRSLspnk2ie@xpf.sh.intel.com/
Fixes: 89ae89f53d20 ("bpf: Add multi uprobe link") Fixes: e420bed02507 ("bpf: Add fd-based tcx multi-prog infra with link support") Fixes: 84601d6ee68a ("bpf: add bpf_link support for BPF_NETFILTER programs") Fixes: 35dfaad7188c ("netkit, bpf: Add bpf programmable net device") Reported-by: Pengfei Xu pengfei.xu@intel.com Signed-off-by: Jiri Olsa jolsa@kernel.org Signed-off-by: Andrii Nakryiko andrii@kernel.org Tested-by: Pengfei Xu pengfei.xu@intel.com Acked-by: Hou Tao houtao1@huawei.com Link: https://lore.kernel.org/bpf/20231215230502.2769743-1-jolsa@kernel.org Cc: stable@vger.kernel.org # 6.6 Signed-off-by: Ignat Korchagin ignat@cloudflare.com
Hi,
We have experienced a KASAN warning in production on a 6.6 kernel, similar to [1]. This backported patch was adjusted to apply onto 6.6 stable branch: the only change is dropping the BPF_LINK_TYPE(BPF_LINK_TYPE_NETKIT, netkit) definition from the header as netkit was only introduced in 6.7 and 6.7 has the backport already.
I was not able to run the syzkaller reproducer from [1], but we have not seen the KASAN warning in production since applying this patch internally.
Looks good, thanks for the backport, now queued up.
greg k-h