Re: [PATCH v2 00/12] remove_conflicting_framebuffers() cleanup
On Fri, Aug 31, 2018 at 10:07:42AM +0100, Chris Wilson wrote: [...] > Ahah, someone is looking at remove_conflicting_framebuffers(). May I > interest you in a use-after-free? > [ 378.423513] stack segment: [#1] PREEMPT SMP PTI > [ 378.423530] CPU: 1 PID: 4338 Comm: pm_rpm Tainted: G U > 4.19.0-rc1-CI-CI_DRM_4746+ #1 > [ 378.423548] Hardware name: To Be Filled By O.E.M. To Be Filled By > O.E.M./J4205-ITX, BIOS P1.10 09/29/2016 > [ 378.423570] RIP: 0010:do_remove_conflicting_framebuffers+0x56/0x170 > [ 378.423587] Code: 49 8b 45 00 48 85 c0 74 50 f6 40 0a 08 74 4a 4d 85 e4 48 > 8b a8 78 04 00 00 74 1f 48 85 ed 74 1a 41 8b 0c 24 31 db 85 c9 74 10 <8b> 55 > 00 85 d2 75 42 83 c3 01 41 39 1c 24 77 f0 48 85 ed 74 1a 45 > [ 378.423620] RSP: 0018:c91dfa88 EFLAGS: 00010202 > [ 378.423632] RAX: 880274470008 RBX: RCX: > 0001 > [ 378.423646] RDX: 0001 RSI: a025c634 RDI: > 88025cc3b428 > [ 378.423660] RBP: 6b6b6b6b6b6b6b6b R08: 1edaddfa R09: > a025c634 > [ 378.423673] R10: c91dfae8 R11: 820de938 R12: > 88025cc3b428 > [ 378.423687] R13: 8234ca20 R14: 8234cb20 R15: > 0001 > [ 378.423701] FS: 7fcf03d0a980() GS:880277e8() > knlGS: > [ 378.423717] CS: 0010 DS: ES: CR0: 80050033 > [ 378.423729] CR2: 7fffece1fdb8 CR3: 0001fe32e000 CR4: > 003406e0 > [ 378.423742] Call Trace: > [ 378.423756] remove_conflicting_framebuffers+0x28/0x40 > [ 378.423856] i915_driver_load+0x7f5/0x10c0 [i915] [...] Looks like registered_fb[] entry is pointing to (partially?) freed or corrupted fb_info, but I can't see how this could be an effect of remove_conflicting_framebuffers(). Best Regards, Michał Mirosław ___ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization
Re: [PATCH v2 00/12] remove_conflicting_framebuffers() cleanup
Quoting Daniel Vetter (2018-08-31 10:04:39) > On Thu, Aug 30, 2018 at 11:00:01PM +0200, Michał Mirosław wrote: > > This series cleans up duplicated code for replacing firmware FB > > driver with proper DRI driver and adds handover support to > > Tegra driver. > > > > This is a sligtly updated version of a series sent on 24 Nov 2017. > > > > v2: > > - rebased on current drm-next > > - dropped staging/sm750fb changes > > - added kernel docs for DRM helpers > > > > Michał Mirosław (12): > > fbdev: show fbdev number for debugging > > fbdev: allow apertures == NULL in remove_conflicting_framebuffers() > > fbdev: add remove_conflicting_pci_framebuffers() > > drm/amdgpu: use simpler remove_conflicting_pci_framebuffers() > > drm/bochs: use simpler remove_conflicting_pci_framebuffers() > > drm/cirrus: use simpler remove_conflicting_pci_framebuffers() > > drm/mgag200: use simpler remove_conflicting_pci_framebuffers() > > drm/radeon: use simpler remove_conflicting_pci_framebuffers() > > drm/virtio: use simpler remove_conflicting_pci_framebuffers() > > drm/vc4: use simpler remove_conflicting_framebuffers(NULL) > > drm/sun4i: use simpler remove_conflicting_framebuffers(NULL) > > drm/tegra: kick out simplefb > > Looks very neat. A bit confused about the drm changes in the fbdev-titled > patches 1&3, but I guess we can merge as-is. Up to you whether you want to > split or not I'd say. Ahah, someone is looking at remove_conflicting_framebuffers(). May I interest you in a use-after-free? [ 378.423513] stack segment: [#1] PREEMPT SMP PTI [ 378.423530] CPU: 1 PID: 4338 Comm: pm_rpm Tainted: G U 4.19.0-rc1-CI-CI_DRM_4746+ #1 [ 378.423548] Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./J4205-ITX, BIOS P1.10 09/29/2016 [ 378.423570] RIP: 0010:do_remove_conflicting_framebuffers+0x56/0x170 [ 378.423587] Code: 49 8b 45 00 48 85 c0 74 50 f6 40 0a 08 74 4a 4d 85 e4 48 8b a8 78 04 00 00 74 1f 48 85 ed 74 1a 41 8b 0c 24 31 db 85 c9 74 10 <8b> 55 00 85 d2 75 42 83 c3 01 41 39 1c 24 77 f0 48 85 ed 74 1a 45 [ 378.423620] RSP: 0018:c91dfa88 EFLAGS: 00010202 [ 378.423632] RAX: 880274470008 RBX: RCX: 0001 [ 378.423646] RDX: 0001 RSI: a025c634 RDI: 88025cc3b428 [ 378.423660] RBP: 6b6b6b6b6b6b6b6b R08: 1edaddfa R09: a025c634 [ 378.423673] R10: c91dfae8 R11: 820de938 R12: 88025cc3b428 [ 378.423687] R13: 8234ca20 R14: 8234cb20 R15: 0001 [ 378.423701] FS: 7fcf03d0a980() GS:880277e8() knlGS: [ 378.423717] CS: 0010 DS: ES: CR0: 80050033 [ 378.423729] CR2: 7fffece1fdb8 CR3: 0001fe32e000 CR4: 003406e0 [ 378.423742] Call Trace: [ 378.423756] remove_conflicting_framebuffers+0x28/0x40 [ 378.423856] i915_driver_load+0x7f5/0x10c0 [i915] [ 378.423873] ? _raw_spin_unlock_irqrestore+0x4c/0x60 [ 378.423887] ? lockdep_hardirqs_on+0xe0/0x1b0 [ 378.423962] i915_pci_probe+0x29/0xa0 [i915] [ 378.423977] pci_device_probe+0xa1/0x130 [ 378.423990] really_probe+0x25d/0x3c0 [ 378.424002] driver_probe_device+0x10a/0x120 [ 378.424013] __driver_attach+0xdb/0x100 [ 378.424025] ? driver_probe_device+0x120/0x120 [ 378.424037] bus_for_each_dev+0x74/0xc0 [ 378.424048] bus_add_driver+0x15f/0x250 [ 378.424060] ? 0xa069d000 [ 378.424070] driver_register+0x56/0xe0 [ 378.424080] ? 0xa069d000 [ 378.424090] do_one_initcall+0x58/0x2e0 [ 378.424101] ? rcu_lockdep_current_cpu_online+0x8f/0xd0 [ 378.424116] ? do_init_module+0x1d/0x1ea [ 378.424127] ? rcu_read_lock_sched_held+0x6f/0x80 [ 378.424141] ? kmem_cache_alloc_trace+0x264/0x290 [ 378.424154] do_init_module+0x56/0x1ea [ 378.424167] load_module+0x26ba/0x29a0 [ 378.424182] ? vfs_read+0x122/0x140 [ 378.424199] ? __se_sys_finit_module+0xd3/0xf0 [ 378.424210] __se_sys_finit_module+0xd3/0xf0 [ 378.424226] do_syscall_64+0x55/0x190 [ 378.424237] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 378.424249] RIP: 0033:0x7fcf02f9b839 [ 378.424258] Code: 00 f3 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 1f f6 2c 00 f7 d8 64 89 01 48 [ 378.424290] RSP: 002b:7fffece21f58 EFLAGS: 0246 ORIG_RAX: 0139 [ 378.424307] RAX: ffda RBX: 56344e1a4d80 RCX: 7fcf02f9b839 [ 378.424321] RDX: RSI: 7fcf026470e5 RDI: 0003 [ 378.424336] RBP: 7fcf026470e5 R08: R09: [ 378.424349] R10: 0003 R11: 0246 R12: [ 378.424363] R13: 56344e1a R14: R15: 56344e1a4d80 https://intel-gfx-ci.01.org/tree/drm-tip/IGT_4613/fi-bxt-j4205/dmesg0.log -Chris ___ Virtualization mailing list
