6.5-stable review patch. If anyone has any objections, please let me know.
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From: Kui-Feng Lee thinker.li@gmail.com
[ 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@linaro.org Closes: https://lore.kernel.org/bpf/d1360219-85c3-4a03-9449-253ea905f9d1@moroto.moun... Fixes: 66e3a13e7c2c ("bpf: Add bpf_dynptr_slice and bpf_dynptr_slice_rdwr") Suggested-by: Alexei Starovoitov alexei.starovoitov@gmail.com Signed-off-by: Kui-Feng Lee thinker.li@gmail.com Acked-by: Yonghong Song yonghong.song@linux.dev Link: https://lore.kernel.org/r/20230803231206.1060485-1-thinker.li@gmail.com Signed-off-by: Martin KaFai Lau martin.lau@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- 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 9e80efa59a5d6..8812397a5cd96 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -2243,7 +2243,7 @@ __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;
if (!buffer__opt)