lkml.org 
[lkml]   [2022]   [Aug]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 5.10 472/545] iommu/vt-d: avoid invalid memory access via node_online(NUMA_NO_NODE)
    Date
    From: Alexander Lobakin <alexandr.lobakin@intel.com>

    [ Upstream commit b0b0b77ea611e3088e9523e60860f4f41b62b235 ]

    KASAN reports:

    [ 4.668325][ T0] BUG: KASAN: wild-memory-access in dmar_parse_one_rhsa (arch/x86/include/asm/bitops.h:214 arch/x86/include/asm/bitops.h:226 include/asm-generic/bitops/instrumented-non-atomic.h:142 include/linux/nodemask.h:415 drivers/iommu/intel/dmar.c:497)
    [ 4.676149][ T0] Read of size 8 at addr 1fffffff85115558 by task swapper/0/0
    [ 4.683454][ T0]
    [ 4.685638][ T0] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.19.0-rc3-00004-g0e862838f290 #1
    [ 4.694331][ T0] Hardware name: Supermicro SYS-5018D-FN4T/X10SDV-8C-TLN4F, BIOS 1.1 03/02/2016
    [ 4.703196][ T0] Call Trace:
    [ 4.706334][ T0] <TASK>
    [ 4.709133][ T0] ? dmar_parse_one_rhsa (arch/x86/include/asm/bitops.h:214 arch/x86/include/asm/bitops.h:226 include/asm-generic/bitops/instrumented-non-atomic.h:142 include/linux/nodemask.h:415 drivers/iommu/intel/dmar.c:497)

    after converting the type of the first argument (@nr, bit number)
    of arch_test_bit() from `long` to `unsigned long`[0].

    Under certain conditions (for example, when ACPI NUMA is disabled
    via command line), pxm_to_node() can return %NUMA_NO_NODE (-1).
    It is valid 'magic' number of NUMA node, but not valid bit number
    to use in bitops.
    node_online() eventually descends to test_bit() without checking
    for the input, assuming it's on caller side (which might be good
    for perf-critical tasks). There, -1 becomes %ULONG_MAX which leads
    to an insane array index when calculating bit position in memory.

    For now, add an explicit check for @node being not %NUMA_NO_NODE
    before calling test_bit(). The actual logics didn't change here
    at all.

    [0] https://github.com/norov/linux/commit/0e862838f290147ea9c16db852d8d494b552d38d

    Fixes: ee34b32d8c29 ("dmar: support for parsing Remapping Hardware Static Affinity structure")
    Cc: stable@vger.kernel.org # 2.6.33+
    Reported-by: kernel test robot <oliver.sang@intel.com>
    Signed-off-by: Alexander Lobakin <alexandr.lobakin@intel.com>
    Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
    Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
    Signed-off-by: Yury Norov <yury.norov@gmail.com>
    Signed-off-by: Sasha Levin <sashal@kernel.org>
    ---
    drivers/iommu/intel/dmar.c | 2 +-
    1 file changed, 1 insertion(+), 1 deletion(-)

    diff --git a/drivers/iommu/intel/dmar.c b/drivers/iommu/intel/dmar.c
    index 70d569b80ecf..0bc497f4cb9f 100644
    --- a/drivers/iommu/intel/dmar.c
    +++ b/drivers/iommu/intel/dmar.c
    @@ -497,7 +497,7 @@ static int dmar_parse_one_rhsa(struct acpi_dmar_header *header, void *arg)
    if (drhd->reg_base_addr == rhsa->base_address) {
    int node = pxm_to_node(rhsa->proximity_domain);

    - if (!node_online(node))
    + if (node != NUMA_NO_NODE && !node_online(node))
    node = NUMA_NO_NODE;
    drhd->iommu->node = node;
    return 0;
    --
    2.35.1


    \
     
     \ /
      Last update: 2022-08-19 18:46    [W:2.217 / U:0.348 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site