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| author | Michael Brown | 2011-07-16 02:46:12 +0200 |
|---|---|---|
| committer | Michael Brown | 2011-07-16 02:49:47 +0200 |
| commit | 17f09dfe03a8c6b46d30844d3cee28266b6971fe (patch) | |
| tree | 519f0c558d7e5dc4a2387fcc16ab3d7c6405b7d1 /src/net/retry.c | |
| parent | [ipv4] Use broadcast link-layer address for all broadcast IPv4 addresses (diff) | |
| download | ipxe-17f09dfe03a8c6b46d30844d3cee28266b6971fe.tar.gz ipxe-17f09dfe03a8c6b46d30844d3cee28266b6971fe.tar.xz ipxe-17f09dfe03a8c6b46d30844d3cee28266b6971fe.zip | |
[retry] Fix potential use-after-free in timer_expired()
timer->refcnt is allowed to be NULL, in which case the timer's
expired() method may end up freeing the timer object.
Discovered using valgrind.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Diffstat (limited to 'src/net/retry.c')
| -rw-r--r-- | src/net/retry.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/src/net/retry.c b/src/net/retry.c index 0aa165ab..7e20f0c8 100644 --- a/src/net/retry.c +++ b/src/net/retry.c @@ -148,6 +148,7 @@ void stop_timer ( struct retry_timer *timer ) { * @v timer Retry timer */ static void timer_expired ( struct retry_timer *timer ) { + struct refcnt *refcnt = timer->refcnt; int fail; /* Stop timer without performing RTT calculations */ @@ -169,8 +170,9 @@ static void timer_expired ( struct retry_timer *timer ) { /* Call expiry callback */ timer->expired ( timer, fail ); + /* If refcnt is NULL, then timer may already have been freed */ - ref_put ( timer->refcnt ); + ref_put ( refcnt ); } /** |