mirror of
https://github.com/hardkernel/linux.git
synced 2026-06-10 12:57:06 +09:00
e3cb0c7102
The commit111e7b15cf("x86/ioperm: Extend IOPL config to control ioperm() as well") replaced X86_IOPL_EMULATION with X86_IOPL_IOPERM. However it appears that there was at least one spot missed as tss_update_io_bitmap() still had a reference to it contained in the code. The result of this is that it exposed a NULL pointer dereference as seen below with a linux-next next-20191120 kernel: BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: 0000 [#1] SMP PTI CPU: 5 PID: 1542 Comm: ovs-vswitchd Tainted: G W 5.4.0-rc8-next-20191120 #125 RIP: 0010:tss_update_io_bitmap+0x4e/0x180 Code: 10 31 c0 65 48 03 1d 69 54 5d 6d 65 48 8b 04 25 40 8c 01 00 48 8b 10 \ f7 c2 00 00 40 00 0f 84 8c 00 00 00 4c 8b a0 c0 22 00 00 <49> 8b 04 \ 24 48 39 43 68 74 2e 8b 53 70 41 39 54 24 0c 48 8d 7b 78 RSP: 0018:ffffb8888a0ebf08 EFLAGS: 00010006 RAX: ffff8a429811a680 RBX: ffff8a4c3f946000 RCX: 0000000000000011 RDX: 0000000000400080 RSI: 0000000000400080 RDI: 0000000000000000 RBP: ffffb8888a0ebf30 R08: 00007ffffb5d7ce0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f68a9635c40(0000) GS:ffff8a4c3f940000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000103572a001 CR4: 00000000001606e0 Call Trace: ? syscall_slow_exit_work+0x39/0xdb do_syscall_64+0x1a5/0x200 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f68a7aff797 Fixes:111e7b15cf("x86/ioperm: Extend IOPL config to control ioperm() as well") Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Rik van Riel <riel@surriel.com> Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/20191120222426.3060.18462.stgit@localhost.localdomain
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.