Date: Sun, 15 Sep 2019 14:12:49 +0000 From: bugzilla-noreply@freebsd.org To: bugs@FreeBSD.org Subject: [Bug 239973] Kernel Panic: device_get_ivars(9) returns NULL which leads to Null pointer dereference for multiple drivers Message-ID: <bug-239973-227-7ovrwmv3ri@https.bugs.freebsd.org/bugzilla/> In-Reply-To: <bug-239973-227@https.bugs.freebsd.org/bugzilla/> References: <bug-239973-227@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D239973 --- Comment #3 from Neeraj <neerajpal09@gmail.com> --- (In reply to Hans Petter Selasky from comment #2) yeah you right. Actually, as per the discussion going in the mailing list, other developers said that the patch is correct *if and only if want to preserve the ivars information* and preserving the info would be a long term solution. But, as you said that there might be a race, that devctl is=20 attaching/detaching drivers while USB is doing the same, it might go into t= he panic due to that. So, you are correct on the point that USB drivers are not supposed to be managed outside the USB enumeration thread. Using devctl on USB driver is n= ot supported. Only usbconfig is allowed to attach/detach USB devices. And, I also think that it is a better solution to blacklist devctl from touching USB device nodes or anything that parents to a usbusX, instead of patching all the devices. As, we already have usbconfig to do the same. --=20 You are receiving this mail because: You are the assignee for the bug.=
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