From 544adb41077a10d299a1094f12ec55a5843a9bdb Mon Sep 17 00:00:00 2001 From: Jesper Juhl Date: Tue, 4 Mar 2008 14:29:00 -0800 Subject: [PATCH] markers: don't risk NULL deref in marker get_marker() may return NULL, so test for it. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Jesper Juhl Acked-by: Mathieu Desnoyers Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/marker.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/kernel/marker.c b/kernel/marker.c index 50effc01d9..48a4ea5aff 100644 --- a/kernel/marker.c +++ b/kernel/marker.c @@ -698,14 +698,12 @@ int marker_probe_unregister(const char *name, { struct marker_entry *entry; struct marker_probe_closure *old; - int ret = 0; + int ret = -ENOENT; mutex_lock(&markers_mutex); entry = get_marker(name); - if (!entry) { - ret = -ENOENT; + if (!entry) goto end; - } if (entry->rcu_pending) rcu_barrier(); old = marker_entry_remove_probe(entry, probe, probe_private); @@ -713,12 +711,15 @@ int marker_probe_unregister(const char *name, marker_update_probes(); /* may update entry */ mutex_lock(&markers_mutex); entry = get_marker(name); + if (!entry) + goto end; entry->oldptr = old; entry->rcu_pending = 1; /* write rcu_pending before calling the RCU callback */ smp_wmb(); call_rcu(&entry->rcu, free_old_closure); remove_marker(name); /* Ignore busy error message */ + ret = 0; end: mutex_unlock(&markers_mutex); return ret; -- 2.39.5