6.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Kui-Feng Lee <thinker.li@xxxxxxxxx> [ Upstream commit 5426700e6841bf72e652e34b5cec68eadf442435 ] Verify if the pointer obtained from bpf_xdp_pointer() is either an error or NULL before returning it. The function bpf_dynptr_slice() mistakenly returned an ERR_PTR. Instead of solely checking for NULL, it should also verify if the pointer returned by bpf_xdp_pointer() is an error or NULL. Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> Closes: https://lore.kernel.org/bpf/d1360219-85c3-4a03-9449-253ea905f9d1@moroto.mountain/ Fixes: 66e3a13e7c2c ("bpf: Add bpf_dynptr_slice and bpf_dynptr_slice_rdwr") Suggested-by: Alexei Starovoitov <alexei.starovoitov@xxxxxxxxx> Signed-off-by: Kui-Feng Lee <thinker.li@xxxxxxxxx> Acked-by: Yonghong Song <yonghong.song@xxxxxxxxx> Link: https://lore.kernel.org/r/20230803231206.1060485-1-thinker.li@xxxxxxxxx Signed-off-by: Martin KaFai Lau <martin.lau@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- kernel/bpf/helpers.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index f12565ba136b0..8c5daa841704b 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -2218,7 +2218,7 @@ __bpf_kfunc void *bpf_dynptr_slice(const struct bpf_dynptr_kern *ptr, u32 offset case BPF_DYNPTR_TYPE_XDP: { void *xdp_ptr = bpf_xdp_pointer(ptr->data, ptr->offset + offset, len); - if (xdp_ptr) + if (!IS_ERR_OR_NULL(xdp_ptr)) return xdp_ptr; bpf_xdp_copy_buf(ptr->data, ptr->offset + offset, buffer, len, false); -- 2.40.1
