The patch titled Subject: cpuidle: add checks to avoid NULL pointer dereference has been added to the -mm tree. Its filename is cpuidle-add-checks-to-avoid-null-pointer-dereference.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Srivatsa S. Bhat <srivatsa.bhat@xxxxxxxxxxxxxxxxxx> Subject: cpuidle: add checks to avoid NULL pointer dereference The existing check for dev == NULL in __cpuidle_register_device() is rendered useless because dev is dereferenced before the check itself. Moreover, correctly speaking, it is the job of the callers of this function, i.e., cpuidle_register_device() & cpuidle_enable_device() (which also happen to be exported functions) to ensure that __cpuidle_register_device() is called with a non-NULL dev. So add the necessary dev == NULL checks in the two callers and remove the (useless) check from __cpuidle_register_device(). Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@xxxxxxxxxxxxxxxxxx> Acked-by: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx> Cc: Len Brown <lenb@xxxxxxxxxx> Cc: "Brown, Len" <len.brown@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- drivers/cpuidle/cpuidle.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff -puN drivers/cpuidle/cpuidle.c~cpuidle-add-checks-to-avoid-null-pointer-dereference drivers/cpuidle/cpuidle.c --- a/drivers/cpuidle/cpuidle.c~cpuidle-add-checks-to-avoid-null-pointer-dereference +++ a/drivers/cpuidle/cpuidle.c @@ -285,6 +285,9 @@ int cpuidle_enable_device(struct cpuidle int ret, i; struct cpuidle_driver *drv = cpuidle_get_driver(); + if (!dev) + return -EINVAL; + if (dev->enabled) return 0; if (!drv || !cpuidle_curr_governor) @@ -369,8 +372,6 @@ static int __cpuidle_register_device(str struct device *cpu_dev = get_cpu_device((unsigned long)dev->cpu); struct cpuidle_driver *cpuidle_driver = cpuidle_get_driver(); - if (!dev) - return -EINVAL; if (!try_module_get(cpuidle_driver->owner)) return -EINVAL; @@ -395,6 +396,9 @@ int cpuidle_register_device(struct cpuid { int ret; + if (!dev) + return -EINVAL; + mutex_lock(&cpuidle_lock); if ((ret = __cpuidle_register_device(dev))) { _ Subject: Subject: cpuidle: add checks to avoid NULL pointer dereference Patches currently in -mm which might be from srivatsa.bhat@xxxxxxxxxxxxxxxxxx are cpuidle-add-checks-to-avoid-null-pointer-dereference.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html