From b971e7ac834e9f4bda96d5a96ae9abccd01c1dd8 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Mon, 10 Nov 2008 21:43:08 -0800 Subject: [PATCH] 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: Alexey Dobriyan Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/ipv4/proc.c | 58 +++++++++++++++++++++++++------------------------ 1 file changed, 30 insertions(+), 28 deletions(-) diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c index 8f5a403f6f6b..a631a1f110ca 100644 --- a/net/ipv4/proc.c +++ b/net/ipv4/proc.c @@ -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 } -- GitLab