[PATCH 6.4 187/737] bpf: fix bpf_dynptr_slice() to stop return an ERR_PTR.

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



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






[Index of Archives]     [Linux Kernel]     [Kernel Development Newbies]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite Hiking]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux