Messages in this thread Patch in this message | | | Date | Mon, 19 Aug 2019 07:01:06 -0700 | From | tip-bot for Michael Kelley <> | Subject | [tip:irq/urgent] genirq: Properly pair kobject_del() with kobject_add() |
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Commit-ID: e1ee29624746fbf667f80e8ae3815a76e4d1bd5b Gitweb: https://git.kernel.org/tip/e1ee29624746fbf667f80e8ae3815a76e4d1bd5b Author: Michael Kelley <mikelley@microsoft.com> AuthorDate: Thu, 1 Aug 2019 23:53:53 +0000 Committer: Thomas Gleixner <tglx@linutronix.de> CommitDate: Mon, 19 Aug 2019 15:56:28 +0200
genirq: Properly pair kobject_del() with kobject_add()
If alloc_descs() fails before irq_sysfs_init() has run, free_desc() in the cleanup path will call kobject_del() even though the kobject has not been added with kobject_add().
Fix this by making the call to kobject_del() conditional on whether irq_sysfs_init() has run.
This problem surfaced because commit aa30f47cf666 ("kobject: Add support for default attribute groups to kobj_type") makes kobject_del() stricter about pairing with kobject_add(). If the pairing is incorrrect, a WARNING and backtrace occur in sysfs_remove_group() because there is no parent.
[ tglx: Add a comment to the code ]
Fixes: ecb3f394c5db ("genirq: Expose interrupt information through sysfs") Signed-off-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/1564703564-4116-1-git-send-email-mikelley@microsoft.com
--- kernel/irq/irqdesc.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c index 9484e88dabc2..51f42f3caf09 100644 --- a/kernel/irq/irqdesc.c +++ b/kernel/irq/irqdesc.c @@ -437,8 +437,14 @@ static void free_desc(unsigned int irq) * * The sysfs entry must be serialized against a concurrent * irq_sysfs_init() as well. + * + * If irq_sysfs_init() has not yet been invoked (early boot), then + * irq_kobj_base is NULL and the descriptor was never added. + * kobject_del() complains about a object with no parent, so make + * it conditional. */ - kobject_del(&desc->kobj); + if (irq_kobj_base) + kobject_del(&desc->kobj); delete_irq_desc(irq); /*
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