Messages in this thread Patch in this message | | | From | Paul Gortmaker <> | Subject | [v2.6.34-stable 073/165] USB: pid_ns: ensure pid is not freed during kill_pid_info_as_uid | Date | Wed, 15 Aug 2012 15:46:57 -0400 |
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From: Serge Hallyn <serge.hallyn@canonical.com>
------------------- This is a commit scheduled for the next v2.6.34 longterm release. http://git.kernel.org/?p=linux/kernel/git/paulg/longterm-queue-2.6.34.git If you see a problem with using this for longterm, please comment. -------------------
commit aec01c5895051849ed842dc5b8794017a7751f28 upstream.
Alan Stern points out that after spin_unlock(&ps->lock) there is no guarantee that ps->pid won't be freed. Since kill_pid_info_as_uid() is called after the spin_unlock(), the pid passed to it must be pinned.
Reported-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> --- drivers/usb/core/devio.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c index 6088192..85a4967 100644 --- a/drivers/usb/core/devio.c +++ b/drivers/usb/core/devio.c @@ -409,7 +409,7 @@ static void async_completed(struct urb *urb) sinfo.si_errno = as->status; sinfo.si_code = SI_ASYNCIO; sinfo.si_addr = as->userurb; - pid = as->pid; + pid = get_pid(as->pid); uid = as->uid; euid = as->euid; secid = as->secid; @@ -424,9 +424,11 @@ static void async_completed(struct urb *urb) cancel_bulk_urbs(ps, as->bulk_addr); spin_unlock(&ps->lock); - if (signr) + if (signr) { kill_pid_info_as_uid(sinfo.si_signo, &sinfo, pid, uid, euid, secid); + put_pid(pid); + } wake_up(&ps->wait); } -- 1.7.12.rc2
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