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Pengpeng Hou
7c31f7a599
[ Upstream commit5c14a19d5b] s3fwrn82_uart_read() reports the number of accepted bytes to the serdev core. The current code consumes bytes into recv_skb and may already deliver a complete frame before allocating a fresh receive buffer. If that alloc_skb() fails, the callback returns 0 even though it has already consumed bytes, and it leaves recv_skb as NULL for the next receive callback. That breaks the receive_buf() accounting contract and can also lead to a NULL dereference on the next skb_put_u8(). Allocate the receive skb lazily before consuming the next byte instead. If allocation fails, return the number of bytes already accepted. Fixes:3f52c2cb7e("nfc: s3fwrn5: Support a UART interface") Signed-off-by: Pengpeng Hou <pengpeng@iscas.ac.cn> Link: https://patch.msgid.link/20260402042148.65236-1-pengpeng@iscas.ac.cn Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>