Messages in this thread Patch in this message | | | From | Petr Mladek <> | Subject | [PATCH] livepatch: RCU protect struct klp_func all the time when used in klp_ftrace_handler() | Date | Wed, 18 Feb 2015 18:02:13 +0100 |
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func->new_func has been accessed after rcu_read_unlock() in klp_ftrace_handler() and therefore the access was not protected.
Signed-off-by: Petr Mladek <pmladek@suse.cz> --- kernel/livepatch/core.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c index ff7f47d026ac..cde66192e20e 100644 --- a/kernel/livepatch/core.c +++ b/kernel/livepatch/core.c @@ -314,12 +314,12 @@ static void notrace klp_ftrace_handler(unsigned long ip, rcu_read_lock(); func = list_first_or_null_rcu(&ops->func_stack, struct klp_func, stack_node); - rcu_read_unlock(); - if (WARN_ON_ONCE(!func)) - return; + goto unlock; klp_arch_set_pc(regs, (unsigned long)func->new_func); +unlock: + rcu_read_unlock(); } static int klp_disable_func(struct klp_func *func) -- 1.8.5.6
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