redonkable/alistair23-linux
redonkable/alistair23-linux
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[FIB]: Avoid using static variables without proper locking

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fib_trie_seq_show() uses two helper functions, rtn_scope() and
rtn_type() that can write to static storage without locking.

Just pass to them a temporary buffer to avoid potential corruption
(probably not triggerable but still...)

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet 2008-01-14 23:09:56 -08:00 committed by David S. Miller
parent 39a6d06300
commit 28d36e3702
1 changed files with 12 additions and 10 deletions
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22
net/ipv4/fib_trie.c
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@ -2284,10 +2284,8 @@ static void seq_indent(struct seq_file *seq, int n)
while (n-- > 0) seq_puts(seq, " "); while (n-- > 0) seq_puts(seq, " ");
} }
static inline const char *rtn_scope(enum rt_scope_t s) static inline const char *rtn_scope(char *buf, size_t len, enum rt_scope_t s)
{ {
static char buf[32];
switch (s) { switch (s) {
case RT_SCOPE_UNIVERSE: return "universe"; case RT_SCOPE_UNIVERSE: return "universe";
case RT_SCOPE_SITE: return "site"; case RT_SCOPE_SITE: return "site";
@ -2295,7 +2293,7 @@ static inline const char *rtn_scope(enum rt_scope_t s)
case RT_SCOPE_HOST: return "host"; case RT_SCOPE_HOST: return "host";
case RT_SCOPE_NOWHERE: return "nowhere"; case RT_SCOPE_NOWHERE: return "nowhere";
default: default:
snprintf(buf, sizeof(buf), "scope=%d", s); snprintf(buf, len, "scope=%d", s);
return buf; return buf;
} }
} }
@ -2315,13 +2313,11 @@ static const char *rtn_type_names[__RTN_MAX] = {
[RTN_XRESOLVE] = "XRESOLVE", [RTN_XRESOLVE] = "XRESOLVE",
}; };
static inline const char *rtn_type(unsigned t) static inline const char *rtn_type(char *buf, size_t len, unsigned t)
{ {
static char buf[32];
if (t < __RTN_MAX && rtn_type_names[t]) if (t < __RTN_MAX && rtn_type_names[t])
return rtn_type_names[t]; return rtn_type_names[t];
snprintf(buf, sizeof(buf), "type %u", t); snprintf(buf, len, "type %u", t);
return buf; return buf;
} }
@ -2359,13 +2355,19 @@ static int fib_trie_seq_show(struct seq_file *seq, void *v)
seq_printf(seq, " |-- %d.%d.%d.%d\n", NIPQUAD(val)); seq_printf(seq, " |-- %d.%d.%d.%d\n", NIPQUAD(val));
for (i = 32; i >= 0; i--) { for (i = 32; i >= 0; i--) {
struct leaf_info *li = find_leaf_info(l, i); struct leaf_info *li = find_leaf_info(l, i);
if (li) { if (li) {
struct fib_alias *fa; struct fib_alias *fa;
list_for_each_entry_rcu(fa, &li->falh, fa_list) { list_for_each_entry_rcu(fa, &li->falh, fa_list) {
char buf1[32], buf2[32];
seq_indent(seq, iter->depth+1); seq_indent(seq, iter->depth+1);
seq_printf(seq, " /%d %s %s", i, seq_printf(seq, " /%d %s %s", i,
rtn_scope(fa->fa_scope), rtn_scope(buf1, sizeof(buf1),
rtn_type(fa->fa_type)); fa->fa_scope),
rtn_type(buf2, sizeof(buf2),
fa->fa_type));
if (fa->fa_tos) if (fa->fa_tos)
seq_printf(seq, "tos =%d\n", seq_printf(seq, "tos =%d\n",
fa->fa_tos); fa->fa_tos);