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authorJohan Hovold <johan@kernel.org>2018-08-21 11:59:52 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-09-26 08:36:36 +0200
commitb1507f458d22fe86334ebc53b8f26de74598c37a (patch)
tree68223613ef046f1e3182ac267fc053c0c2331f46
parent4236e40a9d4facd4b3e6c67ccc1e486d6254cf50 (diff)
USB: serial: io_ti: fix array underflow in completion handler
commit 691a03cfe8ca483f9c48153b869d354e4ae3abef upstream. As reported by Dan Carpenter, a malicious USB device could set port_number to a negative value and we would underflow the port array in the interrupt completion handler. As these devices only have one or two ports, fix this by making sure we only consider the seventh bit when determining the port number (and ignore bits 0xb0 which are typically set to 0x30). Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable <stable@vger.kernel.org> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/usb/serial/io_ti.h2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/usb/serial/io_ti.h b/drivers/usb/serial/io_ti.h
index 1bd67b24f916..bc9ff5ebd67c 100644
--- a/drivers/usb/serial/io_ti.h
+++ b/drivers/usb/serial/io_ti.h
@@ -178,7 +178,7 @@ struct ump_interrupt {
} __attribute__((packed));
-#define TIUMP_GET_PORT_FROM_CODE(c) (((c) >> 4) - 3)
+#define TIUMP_GET_PORT_FROM_CODE(c) (((c) >> 6) & 0x01)
#define TIUMP_GET_FUNC_FROM_CODE(c) ((c) & 0x0f)
#define TIUMP_INTERRUPT_CODE_LSR 0x03
#define TIUMP_INTERRUPT_CODE_MSR 0x04