1. 26 Apr, 2024 39 commits
  2. 24 Apr, 2024 1 commit
    • Dan Carpenter's avatar
      media: stk1160: fix bounds checking in stk1160_copy_video() · faa4364b
      Dan Carpenter authored
      The subtract in this condition is reversed.  The ->length is the length
      of the buffer.  The ->bytesused is how many bytes we have copied thus
      far.  When the condition is reversed that means the result of the
      subtraction is always negative but since it's unsigned then the result
      is a very high positive value.  That means the overflow check is never
      true.
      
      Additionally, the ->bytesused doesn't actually work for this purpose
      because we're not writing to "buf->mem + buf->bytesused".  Instead, the
      math to calculate the destination where we are writing is a bit
      involved.  You calculate the number of full lines already written,
      multiply by two, skip a line if necessary so that we start on an odd
      numbered line, and add the offset into the line.
      
      To fix this buffer overflow, just take the actual destination where we
      are writing, if the offset is already out of bounds print an error and
      return.  Otherwise, write up to buf->length bytes.
      
      Fixes: 9cb2173e ("[media] media: Add stk1160 new driver (easycap replacement)")
      Signed-off-by: default avatarDan Carpenter <dan.carpenter@linaro.org>
      Reviewed-by: default avatarRicardo Ribalda <ribalda@chromium.org>
      Signed-off-by: default avatarHans Verkuil <hverkuil-cisco@xs4all.nl>
      faa4364b