From: David Ahern dsahern@kernel.org Subject: tools/accounting/getdelays.c: fix netlink attribute length

A recent change to the netlink code: 6e237d099fac ("netlink: Relax attr validation for fixed length types") logs a warning when programs send messages with invalid attributes (e.g., wrong length for a u32). Yafang reported this error message for tools/accounting/getdelays.c.

send_cmd() is wrongly adding 1 to the attribute length. As noted in include/uapi/linux/netlink.h nla_len should be NLA_HDRLEN + payload length, so drop the +1.

Link: http://lkml.kernel.org/r/20200327173111.63922-1-dsahern@kernel.org Fixes: 9e06d3f9f6b1 ("per task delay accounting taskstats interface: documentation fix") Signed-off-by: David Ahern dsahern@kernel.org Reported-by: Yafang Shao laoar.shao@gmail.com Tested-by: Yafang Shao laoar.shao@gmail.com Cc: Johannes Berg johannes@sipsolutions.net Cc: Shailabh Nagar nagar@watson.ibm.com Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org ---

tools/accounting/getdelays.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/tools/accounting/getdelays.c~getdelays-fix-netlink-attribute-length +++ a/tools/accounting/getdelays.c @@ -136,7 +136,7 @@ static int send_cmd(int sd, __u16 nlmsg_ msg.g.version = 0x1; na = (struct nlattr *) GENLMSG_DATA(&msg); na->nla_type = nla_type; - na->nla_len = nla_len + 1 + NLA_HDRLEN; + na->nla_len = nla_len + NLA_HDRLEN; memcpy(NLA_DATA(na), nla_data, nla_len); msg.n.nlmsg_len += NLMSG_ALIGN(na->nla_len);

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