<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <style type="text/css" style="display:none;"> P {margin-top:0;margin-bottom:0;} </style> </head> <body dir="ltr"> <div><span style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">Thank you all!</span></div> <div class="elementToProof"><span style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof"><br> </span></div> <div class="elementToProof"><span style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">Regards,<br> </span></div> <div class="elementToProof"><span style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">Lingkai<br> </span></div> <div class="elementToProof" style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);"> <br> </div> <div id="appendonsend"></div> <hr style="display:inline-block;width:98%" tabindex="-1"> <div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" style="font-size:11pt" color="#000000"><b>From:</b> Christian König <christian.koenig@amd.com><br> <b>Sent:</b> Thursday, December 7, 2023 1:55 PM<br> <b>To:</b> Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>; Linus Walleij <linus.walleij@linaro.org>; Lingkai Dong <Lingkai.Dong@arm.com>; Tvrtko Ursulin <tvrtko.ursulin@intel.com><br> <b>Cc:</b> nd <nd@arm.com>; dri-devel@lists.freedesktop.org <dri-devel@lists.freedesktop.org><br> <b>Subject:</b> Re: [PATCH] drm: Fix FD ownership check in drm_master_check_perm()</font> <div> </div> </div> <div class="BodyFragment"><font size="2"><span style="font-size:11pt;"> <div class="PlainText">Am 07.12.23 um 11:22 schrieb Tvrtko Ursulin:<br> ><br> ><br> > On 07/12/2023 10:18, Christian König wrote:<br> >> Am 07.12.23 um 11:12 schrieb Linus Walleij:<br> >>> On Wed, Dec 6, 2023 at 2:52 PM Lingkai Dong <Lingkai.Dong@arm.com> <br> >>> wrote:<br> >>><br> >>>> The DRM subsystem keeps a record of the owner of a DRM device file<br> >>>> descriptor using thread group ID (TGID) instead of process ID <br> >>>> (PID), to<br> >>>> ensures all threads within the same userspace process are <br> >>>> considered the<br> >>>> owner. However, the DRM master ownership check compares the current<br> >>>> thread's PID against the record, so the thread is incorrectly <br> >>>> considered to<br> >>>> be not the FD owner if the PID is not equal to the TGID. This <br> >>>> causes DRM<br> >>>> ioctls to be denied master privileges, even if the same thread that <br> >>>> opened<br> >>>> the FD performs an ioctl. Fix this by checking TGID.<br> >>>><br> >>>> Fixes: 4230cea89cafb ("drm: Track clients by tgid and not tid")<br> >>>> Signed-off-by: Lingkai Dong <lingkai.dong@arm.com><br> >>> Paging the patch author (Tvrko) and committer (Christian).<br> >>> Here is the patch if you don't have it in your mailbox:<br> >>> <a href="https://lore.kernel.org/dri-devel/PA6PR08MB107665920BE9A96658CDA04CE8884A@PA6PR08MB10766.eurprd08.prod.outlook.com/"> https://lore.kernel.org/dri-devel/PA6PR08MB107665920BE9A96658CDA04CE8884A@PA6PR08MB10766.eurprd08.prod.outlook.com/</a> <br> >>><br> >>><br> >>> I'm seeing this as well (on Android).<br> >>><br> >>> Tvrko, Christian: can you look at this?<br> >><br> >> Good catch, looks like we missed this occasion while switching from <br> >> PID to TGID.<br> ><br> > Oops, yes..<br> ><br> > Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com><br> ><br> >>> Will you apply it to the AMD tree for fixes if it looks OK<br> >>> or does it go elsewhere?<br> >><br> >> I can push this to drm-misc-fixes as long as nobody objects in the <br> >> next hour or so.<br> >><br> >> CC: stable? If yes which versions?<br> ><br> > Cc: <stable@vger.kernel.org> # v6.4+<br> <br> And pushed to drm-misc-fixes.<br> <br> Thanks,<br> Christian.<br> <br> ><br> > Regards,<br> ><br> > Tvrtko<br> <br> </div> </span></font></div> </body> </html>