On 2019/9/19 14:36, Greg KH wrote: > On Thu, Sep 19, 2019 at 10:58:06AM +0800, Xiaoming Ni wrote: >> Registering the same notifier to a hook repeatedly can cause the hook >> list to form a ring or lose other members of the list. >> >> case1: An infinite loop in notifier_chain_register() can cause soft lockup >> atomic_notifier_chain_register(&test_notifier_list, &test1); >> atomic_notifier_chain_register(&test_notifier_list, &test1); >> atomic_notifier_chain_register(&test_notifier_list, &test2); >> >> case2: An infinite loop in notifier_chain_register() can cause soft lockup >> atomic_notifier_chain_register(&test_notifier_list, &test1); >> atomic_notifier_chain_register(&test_notifier_list, &test1); >> atomic_notifier_call_chain(&test_notifier_list, 0, NULL); >> >> case3: lose other hook test2 >> atomic_notifier_chain_register(&test_notifier_list, &test1); >> atomic_notifier_chain_register(&test_notifier_list, &test2); >> atomic_notifier_chain_register(&test_notifier_list, &test1); >> >> case4: Unregister returns 0, but the hook is still in the linked list, >> and it is not really registered. If you call notifier_call_chain >> after ko is unloaded, it will trigger oops. >> >> If the system is configured with softlockup_panic and the same >> hook is repeatedly registered on the panic_notifier_list, it >> will cause a loop panic. >> >> Add a check in notifier_chain_register(), >> Intercepting duplicate registrations to avoid infinite loops >> >> Signed-off-by: Xiaoming Ni <nixiaoming@xxxxxxxxxx> >> Reviewed-by: Vasily Averin <vvs@xxxxxxxxxxxxx> >> --- >> kernel/notifier.c | 5 ++++- >> 1 file changed, 4 insertions(+), 1 deletion(-) > > <formletter> > > This is not the correct way to submit patches for inclusion in the > stable kernel tree. Please read: > https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html > for how to do this properly. > thanks for your guidance I thought that as long as the code exists in the stable branch, it should be copied to stable@xxxxxxxxxx it is my mistake, These patches are intended to be sent to the main line. Should I resend it again? > </formletter> > > Same thing goes for all of the patches in this series. > > thanks, > > greg k-h > > . > thanks Xiaoming Ni
