3.2.97-rc1 review patch. If anyone has any objections, please let me know.
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From: Takashi Iwai tiwai@suse.de
commit 7682e399485fe19622b6fd82510b1f4551e48a25 upstream.
The usx2y driver allocates the stream read/write buffers in continuous pages depending on the stream setup, and this may spew the kernel warning messages with a stack trace like: WARNING: CPU: 1 PID: 1846 at mm/page_alloc.c:3883 __alloc_pages_slowpath+0x1ef2/0x2d70 Modules linked in: CPU: 1 PID: 1846 Comm: kworker/1:2 Not tainted ....
It may confuse user as if it were any serious error, although this is no fatal error and the driver handles the error case gracefully. Since the driver has already some sanity check of the given size (128 and 256 pages), it can't pass any crazy value. So it's merely page fragmentation.
This patch adds __GFP_NOWARN to each caller for suppressing such kernel warnings. The original issue was spotted by syzkaller.
Reported-by: Andrey Konovalov andreyknvl@google.com Tested-by: Andrey Konovalov andreyknvl@google.com Signed-off-by: Takashi Iwai tiwai@suse.de Signed-off-by: Ben Hutchings ben@decadent.org.uk --- sound/usb/usx2y/usb_stream.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
--- a/sound/usb/usx2y/usb_stream.c +++ b/sound/usb/usx2y/usb_stream.c @@ -192,7 +192,8 @@ struct usb_stream *usb_stream_new(struct }
pg = get_order(read_size); - sk->s = (void *) __get_free_pages(GFP_KERNEL|__GFP_COMP|__GFP_ZERO, pg); + sk->s = (void *) __get_free_pages(GFP_KERNEL|__GFP_COMP|__GFP_ZERO| + __GFP_NOWARN, pg); if (!sk->s) { snd_printk(KERN_WARNING "couldn't __get_free_pages()\n"); goto out; @@ -212,7 +213,8 @@ struct usb_stream *usb_stream_new(struct pg = get_order(write_size);
sk->write_page = - (void *)__get_free_pages(GFP_KERNEL|__GFP_COMP|__GFP_ZERO, pg); + (void *)__get_free_pages(GFP_KERNEL|__GFP_COMP|__GFP_ZERO| + __GFP_NOWARN, pg); if (!sk->write_page) { snd_printk(KERN_WARNING "couldn't __get_free_pages()\n"); usb_stream_free(sk);