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author | Ananth N Mavinakayanahalli <ananth@in.ibm.com> | 2012-01-20 14:34:04 -0800 |
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committer | Greg Kroah-Hartman <gregkh@suse.de> | 2012-01-25 16:13:57 -0800 |
commit | 6ee7663e972835367a550bd6b9fecc1a9dc14ce1 (patch) | |
tree | dbce6c001ccf5319ccbd5a0b2b45a4f75756fa65 | |
parent | bdac3a105a1c8fdf89ea15404ad5c7bcec73d37a (diff) | |
download | lwn-6ee7663e972835367a550bd6b9fecc1a9dc14ce1.tar.gz lwn-6ee7663e972835367a550bd6b9fecc1a9dc14ce1.zip |
kprobes: initialize before using a hlist
commit d496aab567e7e52b3e974c9192a5de6e77dce32c upstream.
Commit ef53d9c5e ("kprobes: improve kretprobe scalability with hashed
locking") introduced a bug where we can potentially leak
kretprobe_instances since we initialize a hlist head after having used
it.
Initialize the hlist head before using it.
Reported by: Jim Keniston <jkenisto@us.ibm.com>
Acked-by: Jim Keniston <jkenisto@us.ibm.com>
Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Srinivasa D S <srinivasa@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
-rw-r--r-- | kernel/kprobes.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/kprobes.c b/kernel/kprobes.c index e5d84644823b..52fd0499573f 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -1077,6 +1077,7 @@ void __kprobes kprobe_flush_task(struct task_struct *tk) /* Early boot. kretprobe_table_locks not yet initialized. */ return; + INIT_HLIST_HEAD(&empty_rp); hash = hash_ptr(tk, KPROBE_HASH_BITS); head = &kretprobe_inst_table[hash]; kretprobe_table_lock(hash, &flags); @@ -1085,7 +1086,6 @@ void __kprobes kprobe_flush_task(struct task_struct *tk) recycle_rp_inst(ri, &empty_rp); } kretprobe_table_unlock(hash, &flags); - INIT_HLIST_HEAD(&empty_rp); hlist_for_each_entry_safe(ri, node, tmp, &empty_rp, hlist) { hlist_del(&ri->hlist); kfree(ri); |