7.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ji-Ze Hong (Peter Hong) commit 7f85d1170575645f9f327062d78017a23b2714eb upstream. The struct f81604_int_data defines 9 bytes of interrupt data: - Byte 0: Status register (sr) - Byte 1: Interrupt register (isrc) - Byte 2: Interrupt enable register (ier) - Byte 3: Arbitration lost capture (alc) - Byte 4: Error code capture (ecc) - Byte 5: Error warning limit register (ewlr) - Byte 6: RX error counter (rxerr) - Byte 7: TX error counter (txerr) - Byte 8: Reserved (val) The hardware sends exactly 9 bytes for the interrupt endpoint. However, the struct was defined with __aligned(4) attribute which caused the compiler to pad the struct to 12 bytes. This causes a problem in f81604_read_int_callback() where the short URB check compares urb->actual_length against sizeof(*data). When sizeof(struct f81604_int_data) is 12 but the hardware only sends 9 bytes, the check fails and valid interrupt messages are discarded. This results in the driver only being able to transmit once because the TX complete interrupt is never processed. Fix this by removing the __aligned(4) attribute so the struct size matches the actual hardware data size of 9 bytes. Fixes: 7299b1b39a25 ("can: usb: f81604: handle short interrupt urb messages properly") Cc: stable@vger.kernel.org Reported-by: Dynetrex, Admin Closes: https://lore.kernel.org/all/A3834A07-5639-4779-844F-C5843DFC3928@dynetrex.com/ Signed-off-by: Ji-Ze Hong (Peter Hong) Acked-by: Greg Kroah-Hartman Tested-by: Drew Willey Link: https://patch.msgid.link/20260824-f81604-fix-v2-1-fc9be5581394@fintek.com.tw Signed-off-by: Marc Kleine-Budde Signed-off-by: Greg Kroah-Hartman --- drivers/net/can/usb/f81604.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/net/can/usb/f81604.c +++ b/drivers/net/can/usb/f81604.c @@ -169,7 +169,7 @@ struct f81604_int_data { u8 rxerr; u8 txerr; u8 val; -} __packed __aligned(4); +} __packed; struct f81604_sff { __be16 id;