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When booting Hyper-V Generation 2 guests KASAN reports the following out-of-bounds access: BUG: KASAN: slab-out-of-bounds in fb_is_primary_device+0x58/0x70 at addr ffff880079cf0eb0 Read of size 8 by task swapper/0/1 ... [<ffffffff81581308>] dump_stack+0x63/0x8b [<ffffffff812e1f99>] print_trailer+0xf9/0x150 [<ffffffff812e7344>] object_err+0x34/0x40 [<ffffffff812e9630>] kasan_report_error+0x230/0x550 [<ffffffff812e9ee8>] kasan_report+0x58/0x60 [<ffffffff812e4500>] ? ___slab_alloc+0x80/0x490 [<ffffffff81878a28>] ? fb_is_primary_device+0x58/0x70 [<ffffffff812e87cd>] __asan_load8+0x5d/0x70 [<ffffffff81878a28>] fb_is_primary_device+0x58/0x70 [<ffffffff8162357a>] register_framebuffer+0xda/0x5b0 [<ffffffff816234a0>] ? remove_conflicting_framebuffers+0x50/0x50 ... The issue is caused by the to_pci_dev() call with no check that the given info->device is in fact a PCI device and some FB devices (Hyper-V FB, EFI FB,...) are not. While on it, clean up the function. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Cc: Bjorn Helgaas <helgaas@kernel.org> Cc: Cathy Avery <cavery@redhat.com> Cc: K. Y. Srinivasan <kys@microsoft.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1458030033-10122-1-git-send-email-vkuznets@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
40 lines
874 B
C
40 lines
874 B
C
/*
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* Copyright (C) 2007 Antonino Daplas <adaplas@gmail.com>
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file COPYING in the main directory of this archive
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* for more details.
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*
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*/
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#include <linux/fb.h>
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#include <linux/pci.h>
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#include <linux/module.h>
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#include <linux/vgaarb.h>
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int fb_is_primary_device(struct fb_info *info)
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{
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struct device *device = info->device;
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struct pci_dev *default_device = vga_default_device();
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struct pci_dev *pci_dev;
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struct resource *res;
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if (!device || !dev_is_pci(device))
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return 0;
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pci_dev = to_pci_dev(device);
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if (default_device) {
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if (pci_dev == default_device)
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return 1;
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return 0;
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}
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res = pci_dev->resource + PCI_ROM_RESOURCE;
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if (res->flags & IORESOURCE_ROM_SHADOW)
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return 1;
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return 0;
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}
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EXPORT_SYMBOL(fb_is_primary_device);
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MODULE_LICENSE("GPL");
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