generic_set_cmd() and generic_get_cmd() use the low nibble of ctrl->bRequest as an index into con->data[]: u8 cmd = (ctrl->bRequest & 0x0F); /* 0 .. 15 */ ... con->data[cmd] = value; /* OOB when cmd >= 5 */ struct usb_audio_control (include/linux/usb/audio.h) declares data as a 5-element array, so indices 5 through 15 write (or read) up to 44 bytes past the end of the array on the heap. A malicious USB host can craft a class-specific SET_CUR / GET_CUR request with an arbitrary bRequest value, triggering the out-of-bounds access from an IRQ completion handler with no further preconditions. Add an ARRAY_SIZE() guard to both functions. Fixes: d355339eecd9 ("usb: gadget: function: make current f_uac1 implementation legacy") Cc: stable@vger.kernel.org Reviewed-by: Weibin Liu Signed-off-by: Liu Chao --- drivers/usb/gadget/function/f_uac1_legacy.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/usb/gadget/function/f_uac1_legacy.c b/drivers/usb/gadget/function/f_uac1_legacy.c index 3f52099a4..7c8d60c7e 100644 --- a/drivers/usb/gadget/function/f_uac1_legacy.c +++ b/drivers/usb/gadget/function/f_uac1_legacy.c @@ -797,6 +797,9 @@ f_audio_bind(struct usb_configuration *c, struct usb_function *f) static int generic_set_cmd(struct usb_audio_control *con, u8 cmd, int value) { + if (cmd >= ARRAY_SIZE(con->data)) + return -EINVAL; + con->data[cmd] = value; return 0; @@ -804,6 +807,9 @@ static int generic_set_cmd(struct usb_audio_control *con, u8 cmd, int value) static int generic_get_cmd(struct usb_audio_control *con, u8 cmd) { + if (cmd >= ARRAY_SIZE(con->data)) + return -EINVAL; + return con->data[cmd]; } -- 2.50.1