Commit b971e7ac authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

net: fix /proc/net/snmp as memory corruptor



icmpmsg_put() can happily corrupt kernel memory, using a static
table and forgetting to reset an array index in a loop.

Remove the static array since its not safe without proper locking.
Signed-off-by: default avatarAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: default avatarEric Dumazet <dada1@cosmosbay.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 013cd397
......@@ -237,43 +237,45 @@ static const struct snmp_mib snmp4_net_list[] = {
SNMP_MIB_SENTINEL
};
static void icmpmsg_put_line(struct seq_file *seq, unsigned long *vals,
unsigned short *type, int count)
{
int j;
if (count) {
seq_printf(seq, "\nIcmpMsg:");
for (j = 0; j < count; ++j)
seq_printf(seq, " %sType%u",
type[j] & 0x100 ? "Out" : "In",
type[j] & 0xff);
seq_printf(seq, "\nIcmpMsg:");
for (j = 0; j < count; ++j)
seq_printf(seq, " %lu", vals[j]);
}
}
static void icmpmsg_put(struct seq_file *seq)
{
#define PERLINE 16
int j, i, count;
static int out[PERLINE];
int i, count;
unsigned short type[PERLINE];
unsigned long vals[PERLINE], val;
struct net *net = seq->private;
count = 0;
for (i = 0; i < ICMPMSG_MIB_MAX; i++) {
if (snmp_fold_field((void **) net->mib.icmpmsg_statistics, i))
out[count++] = i;
if (count < PERLINE)
continue;
seq_printf(seq, "\nIcmpMsg:");
for (j = 0; j < PERLINE; ++j)
seq_printf(seq, " %sType%u", i & 0x100 ? "Out" : "In",
i & 0xff);
seq_printf(seq, "\nIcmpMsg: ");
for (j = 0; j < PERLINE; ++j)
seq_printf(seq, " %lu",
snmp_fold_field((void **) net->mib.icmpmsg_statistics,
out[j]));
seq_putc(seq, '\n');
}
if (count) {
seq_printf(seq, "\nIcmpMsg:");
for (j = 0; j < count; ++j)
seq_printf(seq, " %sType%u", out[j] & 0x100 ? "Out" :
"In", out[j] & 0xff);
seq_printf(seq, "\nIcmpMsg:");
for (j = 0; j < count; ++j)
seq_printf(seq, " %lu", snmp_fold_field((void **)
net->mib.icmpmsg_statistics, out[j]));
val = snmp_fold_field((void **) net->mib.icmpmsg_statistics, i);
if (val) {
type[count] = i;
vals[count++] = val;
}
if (count == PERLINE) {
icmpmsg_put_line(seq, vals, type, count);
count = 0;
}
}
icmpmsg_put_line(seq, vals, type, count);
#undef PERLINE
}
......
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