From: Denis Efremov > Sent: 30 September 2019 15:02 > > memcpy() call with "idata == NULL && ilen == 0" results in undefined > behavior in ar5523_cmd(). For example, NULL is passed in callchain > "ar5523_stat_work() -> ar5523_cmd_write() -> ar5523_cmd()". This patch > adds idata check before memcpy() call in ar5523_cmd() to prevent an > undefined behavior. > ... > Signed-off-by: Denis Efremov <efremov@xxxxxxxxx> > --- > drivers/net/wireless/ath/ar5523/ar5523.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/net/wireless/ath/ar5523/ar5523.c b/drivers/net/wireless/ath/ar5523/ar5523.c > index b94759daeacc..f25af5bc5282 100644 > --- a/drivers/net/wireless/ath/ar5523/ar5523.c > +++ b/drivers/net/wireless/ath/ar5523/ar5523.c > @@ -255,7 +255,8 @@ static int ar5523_cmd(struct ar5523 *ar, u32 code, const void *idata, > > if (flags & AR5523_CMD_FLAG_MAGIC) > hdr->magic = cpu_to_be32(1 << 24); > - memcpy(hdr + 1, idata, ilen); > + if (idata) > + memcpy(hdr + 1, idata, ilen); That would be better as if (ilen) ... David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)
