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author | Yafang Shao <laoar.shao@gmail.com> | 2023-08-23 02:07:02 +0000 |
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committer | Alexei Starovoitov <ast@kernel.org> | 2023-08-23 09:37:29 -0700 |
commit | d75e30dddf73449bc2d10bb8e2f1a2c446bc67a2 (patch) | |
tree | 42d97e175fd3cd19be6a8fb6c2de96afb9f0646f /tools | |
parent | 29d67fdebc42af6466d1909c60fdd1ef4f3e5240 (diff) | |
download | linux-stable-d75e30dddf73449bc2d10bb8e2f1a2c446bc67a2.tar.gz linux-stable-d75e30dddf73449bc2d10bb8e2f1a2c446bc67a2.tar.bz2 linux-stable-d75e30dddf73449bc2d10bb8e2f1a2c446bc67a2.zip |
bpf: Fix issue in verifying allow_ptr_leaks
After we converted the capabilities of our networking-bpf program from
cap_sys_admin to cap_net_admin+cap_bpf, our networking-bpf program
failed to start. Because it failed the bpf verifier, and the error log
is "R3 pointer comparison prohibited".
A simple reproducer as follows,
SEC("cls-ingress")
int ingress(struct __sk_buff *skb)
{
struct iphdr *iph = (void *)(long)skb->data + sizeof(struct ethhdr);
if ((long)(iph + 1) > (long)skb->data_end)
return TC_ACT_STOLEN;
return TC_ACT_OK;
}
Per discussion with Yonghong and Alexei [1], comparison of two packet
pointers is not a pointer leak. This patch fixes it.
Our local kernel is 6.1.y and we expect this fix to be backported to
6.1.y, so stable is CCed.
[1]. https://lore.kernel.org/bpf/CAADnVQ+Nmspr7Si+pxWn8zkE7hX-7s93ugwC+94aXSy4uQ9vBg@mail.gmail.com/
Suggested-by: Yonghong Song <yonghong.song@linux.dev>
Suggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230823020703.3790-2-laoar.shao@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'tools')
0 files changed, 0 insertions, 0 deletions