dac960: fix undefined behavior on empty string

Fix undefined behavior due to a buffer underrun if an empty string is
written to the proc file.

Signed-off-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Michael Buesch 2009-09-22 16:43:36 -07:00 committed by Linus Torvalds
parent c02e3f361c
commit e898893399

View File

@ -6562,7 +6562,7 @@ static int DAC960_ProcWriteUserCommand(struct file *file,
if (copy_from_user(CommandBuffer, Buffer, Count)) return -EFAULT;
CommandBuffer[Count] = '\0';
Length = strlen(CommandBuffer);
if (CommandBuffer[Length-1] == '\n')
if (Length > 0 && CommandBuffer[Length-1] == '\n')
CommandBuffer[--Length] = '\0';
if (Controller->FirmwareType == DAC960_V1_Controller)
return (DAC960_V1_ExecuteUserCommand(Controller, CommandBuffer)