From 5962b35c1de3254a2f03b95efd3b7854b874d7b7 Mon Sep 17 00:00:00 2001 From: Neil Horman Date: Fri, 3 Feb 2012 05:18:43 +0000 Subject: [PATCH] netprio_cgroup: Fix obo in get_prioidx It was recently pointed out to me that the get_prioidx function sets a bit in the prioidx map prior to checking to see if the index being set is out of bounds. This patch corrects that, avoiding the possiblity of us writing beyond the end of the array Signed-off-by: Neil Horman Reported-by: Stanislaw Gruszka CC: Stanislaw Gruszka CC: "David S. Miller" Signed-off-by: David S. Miller --- net/core/netprio_cgroup.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/net/core/netprio_cgroup.c b/net/core/netprio_cgroup.c index 3a9fd4826b75..9ae183a9a381 100644 --- a/net/core/netprio_cgroup.c +++ b/net/core/netprio_cgroup.c @@ -58,11 +58,12 @@ static int get_prioidx(u32 *prio) spin_lock_irqsave(&prioidx_map_lock, flags); prioidx = find_first_zero_bit(prioidx_map, sizeof(unsigned long) * PRIOIDX_SZ); + if (prioidx == sizeof(unsigned long) * PRIOIDX_SZ) { + spin_unlock_irqrestore(&prioidx_map_lock, flags); + return -ENOSPC; + } set_bit(prioidx, prioidx_map); spin_unlock_irqrestore(&prioidx_map_lock, flags); - if (prioidx == sizeof(unsigned long) * PRIOIDX_SZ) - return -ENOSPC; - atomic_set(&max_prioidx, prioidx); *prio = prioidx; return 0;