Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 4.9 02/60] acpi, nfit: fix acpi_nfit_flush_probe() crash | Date | Mon, 13 Feb 2017 05:03:34 -0800 |
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4.9-stable review patch. If anyone has any objections, please let me know.
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From: Dan Williams <dan.j.williams@intel.com>
commit e471486c13b82b1338d49c798f78bb62b1ed0a9e upstream.
We queue an on-stack work item to 'nfit_wq' and wait for it to complete as part of a 'flush_probe' request. However, if the user cancels the wait we need to make sure the item is flushed from the queue otherwise we are leaving an out-of-scope stack address on the work list.
BUG: unable to handle kernel paging request at ffffbcb3c72f7cd0 IP: [<ffffffffa9413a7b>] __list_add+0x1b/0xb0 [..] RIP: 0010:[<ffffffffa9413a7b>] [<ffffffffa9413a7b>] __list_add+0x1b/0xb0 RSP: 0018:ffffbcb3c7ba7c00 EFLAGS: 00010046 [..] Call Trace: [<ffffffffa90bb11a>] insert_work+0x3a/0xc0 [<ffffffffa927fdda>] ? seq_open+0x5a/0xa0 [<ffffffffa90bb30a>] __queue_work+0x16a/0x460 [<ffffffffa90bbb08>] queue_work_on+0x38/0x40 [<ffffffffc0cf2685>] acpi_nfit_flush_probe+0x95/0xc0 [nfit] [<ffffffffc0cf25d0>] ? nfit_visible+0x40/0x40 [nfit] [<ffffffffa9571495>] wait_probe_show+0x25/0x60 [<ffffffffa9546b30>] dev_attr_show+0x20/0x50
Fixes: 7ae0fa439faf ("nfit, libnvdimm: async region scrub workqueue") Reviewed-by: Vishal Verma <vishal.l.verma@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- drivers/acpi/nfit/core.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
--- a/drivers/acpi/nfit/core.c +++ b/drivers/acpi/nfit/core.c @@ -2704,6 +2704,7 @@ static int acpi_nfit_flush_probe(struct struct acpi_nfit_desc *acpi_desc = to_acpi_nfit_desc(nd_desc); struct device *dev = acpi_desc->dev; struct acpi_nfit_flush_work flush; + int rc; /* bounce the device lock to flush acpi_nfit_add / acpi_nfit_notify */ device_lock(dev); @@ -2716,7 +2717,10 @@ static int acpi_nfit_flush_probe(struct INIT_WORK_ONSTACK(&flush.work, flush_probe); COMPLETION_INITIALIZER_ONSTACK(flush.cmp); queue_work(nfit_wq, &flush.work); - return wait_for_completion_interruptible(&flush.cmp); + + rc = wait_for_completion_interruptible(&flush.cmp); + cancel_work_sync(&flush.work); + return rc; } static int acpi_nfit_clear_to_send(struct nvdimm_bus_descriptor *nd_desc,
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