| From | lizf@kernel ... | Subject | [PATCH 3.4 055/172] USB: usbfs: don't leak kernel data in siginfo | Date | Tue, 16 Jun 2015 16:35:09 +0800 |
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From: Alan Stern <stern@rowland.harvard.edu>
3.4.108-rc1 review patch. If anyone has any objections, please let me know.
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commit f0c2b68198589249afd2b1f2c4e8de8c03e19c16 upstream.
When a signal is delivered, the information in the siginfo structure is copied to userspace. Good security practice dicatates that the unused fields in this structure should be initialized to 0 so that random kernel stack data isn't exposed to the user. This patch adds such an initialization to the two places where usbfs raises signals.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Reported-by: Dave Mielke <dave@mielke.cc> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Zefan Li <lizefan@huawei.com> --- drivers/usb/core/devio.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c index 371fe69..d2ae3d9 100644 --- a/drivers/usb/core/devio.c +++ b/drivers/usb/core/devio.c @@ -444,6 +444,7 @@ static void async_completed(struct urb *urb) as->status = urb->status; signr = as->signr; if (signr) { + memset(&sinfo, 0, sizeof(sinfo)); sinfo.si_signo = as->signr; sinfo.si_errno = as->status; sinfo.si_code = SI_ASYNCIO; @@ -2091,6 +2092,7 @@ static void usbdev_remove(struct usb_device *udev) wake_up_all(&ps->wait); list_del_init(&ps->list); if (ps->discsignr) { + memset(&sinfo, 0, sizeof(sinfo)); sinfo.si_signo = ps->discsignr; sinfo.si_errno = EPIPE; sinfo.si_code = SI_ASYNCIO; -- 1.9.1
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