312d3d4f49
commit 3886a86e7e6cc6ce2ce93c440fecd8f42aed0ce7 upstream. A missing bounds check in vm_access() can lead to an out-of-bounds read or write in the adjacent memory area, since the len attribute is not validated before the memcpy later in the function, potentially hitting: [ 183.637831] BUG: unable to handle page fault for address: ffffc90000c86000 [ 183.637934] #PF: supervisor read access in kernel mode [ 183.637997] #PF: error_code(0x0000) - not-present page [ 183.638059] PGD 100000067 P4D 100000067 PUD 100258067 PMD 106341067 PTE 0 [ 183.638144] Oops: 0000 [#2] PREEMPT SMP NOPTI [ 183.638201] CPU: 3 PID: 1790 Comm: poc Tainted: G D 5.17.0-rc6-ci-drm-11296+ #1 [ 183.638298] Hardware name: Intel Corporation CoffeeLake Client Platform/CoffeeLake H DDR4 RVP, BIOS CNLSFWR1.R00.X208.B00.1905301319 05/30/2019 [ 183.638430] RIP: 0010:memcpy_erms+0x6/0x10 [ 183.640213] RSP: 0018:ffffc90001763d48 EFLAGS: 00010246 [ 183.641117] RAX: ffff888109c14000 RBX: ffff888111bece40 RCX: 0000000000000ffc [ 183.642029] RDX: 0000000000001000 RSI: ffffc90000c86000 RDI: ffff888109c14004 [ 183.642946] RBP: 0000000000000ffc R08: 800000000000016b R09: 0000000000000000 [ 183.643848] R10: ffffc90000c85000 R11: 0000000000000048 R12: 0000000000001000 [ 183.644742] R13: ffff888111bed190 R14: ffff888109c14000 R15: 0000000000001000 [ 183.645653] FS: 00007fe5ef807540(0000) GS:ffff88845b380000(0000) knlGS:0000000000000000 [ 183.646570] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 183.647481] CR2: ffffc90000c86000 CR3: 000000010ff02006 CR4: 00000000003706e0 [ 183.648384] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 183.649271] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 183.650142] Call Trace: [ 183.650988] <TASK> [ 183.651793] vm_access+0x1f0/0x2a0 [i915] [ 183.652726] __access_remote_vm+0x224/0x380 [ 183.653561] mem_rw.isra.0+0xf9/0x190 [ 183.654402] vfs_read+0x9d/0x1b0 [ 183.655238] ksys_read+0x63/0xe0 [ 183.656065] do_syscall_64+0x38/0xc0 [ 183.656882] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 183.657663] RIP: 0033:0x7fe5ef725142 [ 183.659351] RSP: 002b:00007ffe1e81c7e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 [ 183.660227] RAX: ffffffffffffffda RBX: 0000557055dfb780 RCX: 00007fe5ef725142 [ 183.661104] RDX: 0000000000001000 RSI: 00007ffe1e81d880 RDI: 0000000000000005 [ 183.661972] RBP: 00007ffe1e81e890 R08: 0000000000000030 R09: 0000000000000046 [ 183.662832] R10: 0000557055dfc2e0 R11: 0000000000000246 R12: 0000557055dfb1c0 [ 183.663691] R13: 00007ffe1e81e980 R14: 0000000000000000 R15: 0000000000000000 Changes since v1: - Updated if condition with range_overflows_t [Chris Wilson] Fixes: 9f909e215fea ("drm/i915: Implement vm_ops->access for gdb access into mmaps") Signed-off-by: Mastan Katragadda <mastanx.katragadda@intel.com> Suggested-by: Adam Zabrocki <adamza@microsoft.com> Reported-by: Jackson Cody <cody.jackson@intel.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Jon Bloomfield <jon.bloomfield@intel.com> Cc: Sudeep Dutt <sudeep.dutt@intel.com> Cc: <stable@vger.kernel.org> # v5.8+ Reviewed-by: Matthew Auld <matthew.auld@intel.com> [mauld: tidy up the commit message and add Cc: stable] Signed-off-by: Matthew Auld <matthew.auld@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20220303060428.1668844-1-mastanx.katragadda@intel.com (cherry picked from commit 661412e301e2ca86799aa4f400d1cf0bd38c57c6) Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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.