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authorXi Wang <xi.wang@gmail.com>2011-12-22 13:35:22 +0000
committerDavid S. Miller <davem@davemloft.net>2011-12-22 22:34:56 -0500
commita0a129f8b6cff54ab479324a54aefdab5db4f240 (patch)
treed3e74b3a59e0fd9c1173852d200eb8491918a3ff
parente688a604807647c9450f9c12a7cb6d027150a895 (diff)
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rps: fix insufficient bounds checking in store_rps_dev_flow_table_cnt()
Setting a large rps_flow_cnt like (1 << 30) on 32-bit platform will cause a kernel oops due to insufficient bounds checking. if (count > 1<<30) { /* Enforce a limit to prevent overflow */ return -EINVAL; } count = roundup_pow_of_two(count); table = vmalloc(RPS_DEV_FLOW_TABLE_SIZE(count)); Note that the macro RPS_DEV_FLOW_TABLE_SIZE(count) is defined as: ... + (count * sizeof(struct rps_dev_flow)) where sizeof(struct rps_dev_flow) is 8. (1 << 30) * 8 will overflow 32 bits. This patch replaces the magic number (1 << 30) with a symbolic bound. Suggested-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Xi Wang <xi.wang@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--net/core/net-sysfs.c7
1 files changed, 5 insertions, 2 deletions
diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
index c71c434a4c05..385aefe53648 100644
--- a/net/core/net-sysfs.c
+++ b/net/core/net-sysfs.c
@@ -665,11 +665,14 @@ static ssize_t store_rps_dev_flow_table_cnt(struct netdev_rx_queue *queue,
if (count) {
int i;
- if (count > 1<<30) {
+ if (count > INT_MAX)
+ return -EINVAL;
+ count = roundup_pow_of_two(count);
+ if (count > (ULONG_MAX - sizeof(struct rps_dev_flow_table))
+ / sizeof(struct rps_dev_flow)) {
/* Enforce a limit to prevent overflow */
return -EINVAL;
}
- count = roundup_pow_of_two(count);
table = vmalloc(RPS_DEV_FLOW_TABLE_SIZE(count));
if (!table)
return -ENOMEM;