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Avoid possible lock leaking.

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After r343619 ipfw uses own locking for packets flow. PULLUP_LEN() macro
is used in ipfw_chk() to make m_pullup(). When m_pullup() fails, it just
returns via `goto pullup_failed`. There are two places where PULLUP_LEN()
is called with IPFW_PF_RLOCK() held.

Add PULLUP_LEN_LOCKED() macro to use in these places to be able release
the lock, when m_pullup() fails.

Sponsored by:	Yandex LLC
This commit is contained in:
Andrey V. Elsukov 2019-07-29 12:55:48 +00:00
parent 0ce33c042e
commit d4e6a52959
1 changed files with 12 additions and 5 deletions
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17
sys/netpfil/ipfw/ip_fw2.c
View File

@ -1442,9 +1442,9 @@ ipfw_chk(struct ip_fw_args *args)
* pointer might become stale after other pullups (but we never use it
* this way).
*/
#define PULLUP_TO(_len, p, T) PULLUP_LEN(_len, p, sizeof(T))
#define PULLUP_TO(_len, p, T) PULLUP_LEN(_len, p, sizeof(T))
#define EHLEN (eh != NULL ? ((char *)ip - (char *)eh) : 0)
#define PULLUP_LEN(_len, p, T) \
#define _PULLUP_LOCKED(_len, p, T, unlock) \
do { \
int x = (_len) + T + EHLEN; \
if (mem) { \
@ -1453,12 +1453,18 @@ do { \
} else { \
if (__predict_false((m)->m_len < x)) { \
args->m = m = m_pullup(m, x); \
if (m == NULL) \
if (m == NULL) { \
unlock; \
goto pullup_failed; \
} \
} \
p = mtod(m, char *) + (_len) + EHLEN; \
} \
} while (0)
#define PULLUP_LEN(_len, p, T) _PULLUP_LOCKED(_len, p, T, )
#define PULLUP_LEN_LOCKED(_len, p, T) \
_PULLUP_LOCKED(_len, p, T, IPFW_PF_RUNLOCK(chain))
/*
* In case pointers got stale after pullups, update them.
*/
@ -2310,7 +2316,7 @@ do { \
case O_TCPOPTS:
if (proto == IPPROTO_TCP && offset == 0 && ulp){
PULLUP_LEN(hlen, ulp,
PULLUP_LEN_LOCKED(hlen, ulp,
(TCP(ulp)->th_off << 2));
match = tcpopts_match(TCP(ulp), cmd);
}
@ -2335,7 +2341,7 @@ do { \
uint16_t mss, *p;
int i;
PULLUP_LEN(hlen, ulp,
PULLUP_LEN_LOCKED(hlen, ulp,
(TCP(ulp)->th_off << 2));
if ((tcpopts_parse(TCP(ulp), &mss) &
IP_FW_TCPOPT_MSS) == 0)
@ -3182,6 +3188,7 @@ do { \
} /* end of inner loop, scan opcodes */
#undef PULLUP_LEN
#undef PULLUP_LEN_LOCKED
if (done)
break;