3.16.82-rc1 review patch. If anyone has any objections, please let me know.
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From: Denis Efremov efremov@linux.com
commit 315cee426f87658a6799815845788fde965ddaad upstream.
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 ilen check before memcpy() call in ar5523_cmd() to prevent an undefined behavior.
Cc: Pontus Fuchs pontus.fuchs@gmail.com Cc: Kalle Valo kvalo@codeaurora.org Cc: "David S. Miller" davem@davemloft.net Cc: David Laight David.Laight@ACULAB.COM Signed-off-by: Denis Efremov efremov@linux.com Signed-off-by: Kalle Valo kvalo@codeaurora.org Signed-off-by: Ben Hutchings ben@decadent.org.uk --- drivers/net/wireless/ath/ar5523/ar5523.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- 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,
if (flags & AR5523_CMD_FLAG_MAGIC) hdr->magic = cpu_to_be32(1 << 24); - memcpy(hdr + 1, idata, ilen); + if (ilen) + memcpy(hdr + 1, idata, ilen);
cmd->odata = odata; cmd->olen = olen;