Commit-ID: a3125494cff084b098c80bb36fbe2061ffed9d52 Gitweb: http://git.kernel.org/tip/a3125494cff084b098c80bb36fbe2061ffed9d52 Author: Tony Luck <tony.l...@intel.com> AuthorDate: Wed, 6 Apr 2016 10:05:16 +0200 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Wed, 13 Apr 2016 10:54:00 +0200
x86/mce: Avoid using object after free in genpool When we loop over all queued machine check error records to pass them to the registered notifiers we use llist_for_each_entry(). But the loop calls gen_pool_free() for the entry in the body of the loop - and then the iterator looks at node->next after the free. Use llist_for_each_entry_safe() instead. Signed-off-by: Tony Luck <tony.l...@intel.com> Signed-off-by: Borislav Petkov <b...@suse.de> Cc: <sta...@vger.kernel.org> Cc: Gong Chen <gong.c...@linux.intel.com> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Thomas Gleixner <t...@linutronix.de> Cc: linux-edac <linux-e...@vger.kernel.org> Link: http://lkml.kernel.org/r/0205...@agluck-desk.sc.intel.com Link: http://lkml.kernel.org/r/1459929916-12852-4-git-send-email...@alien8.de Signed-off-by: Ingo Molnar <mi...@kernel.org> --- arch/x86/kernel/cpu/mcheck/mce-genpool.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/cpu/mcheck/mce-genpool.c b/arch/x86/kernel/cpu/mcheck/mce-genpool.c index 0a85010..2658e2a 100644 --- a/arch/x86/kernel/cpu/mcheck/mce-genpool.c +++ b/arch/x86/kernel/cpu/mcheck/mce-genpool.c @@ -29,7 +29,7 @@ static char gen_pool_buf[MCE_POOLSZ]; void mce_gen_pool_process(void) { struct llist_node *head; - struct mce_evt_llist *node; + struct mce_evt_llist *node, *tmp; struct mce *mce; head = llist_del_all(&mce_event_llist); @@ -37,7 +37,7 @@ void mce_gen_pool_process(void) return; head = llist_reverse_order(head); - llist_for_each_entry(node, head, llnode) { + llist_for_each_entry_safe(node, tmp, head, llnode) { mce = &node->mce; atomic_notifier_call_chain(&x86_mce_decoder_chain, 0, mce); gen_pool_free(mce_evt_pool, (unsigned long)node, sizeof(*node));
