On Tue, 2017-08-15 at 12:30 +0200, Stefano Brivio wrote:
> The cpumask used in i40e{,vf}_irq_affinity_notify() is allocated
> by irq_affinity_notify() with alloc_cpumask_var(), which doesn't
> allocate NR_CPUS bits, but only nr_cpumask_bits bits. If we just
> dereference it, we'll read way more than what is allocated, e.g.
> 1024 bytes vs. 8 bytes allocated on x86_64 machine with 24 CPUs.
>
> Use cpumask_copy() instead. A comprehensive explanation is given
> in the comments about cpumask_var_t, in include/linux/cpumask.h.
>
> KASAN reports:
> [ 25.242312] BUG: KASAN: slab-out-of-bounds in
> i40e_irq_affinity_notify+0x30/0x50 [i40e] at addr ffff880462eea960
> [ 25.242315] Read of size 1024 by task kworker/2:1/170
> [ 25.242322] CPU: 2 PID: 170 Comm: kworker/2:1 Not tainted 4.11.0-
> 22.el7a.x86_64 #1
> [ 25.242325] Hardware name: HP ProLiant DL380 Gen9, BIOS P89
> 05/06/2015
> [ 25.242336] Workqueue: events irq_affinity_notify
> [ 25.242340] Call Trace:
> [ 25.242350] dump_stack+0x63/0x8d
> [ 25.242358] kasan_object_err+0x21/0x70
> [ 25.242364] kasan_report+0x288/0x540
> [ 25.242397] ? i40e_irq_affinity_notify+0x30/0x50 [i40e]
> [ 25.242403] check_memory_region+0x13c/0x1a0
> [ 25.242408] __asan_loadN+0xf/0x20
> [ 25.242440] i40e_irq_affinity_notify+0x30/0x50 [i40e]
> [ 25.242446] irq_affinity_notify+0x1b4/0x230
> [ 25.242452] ? irq_set_affinity_notifier+0x130/0x130
> [ 25.242457] ? kasan_slab_free+0x89/0xc0
> [ 25.242466] process_one_work+0x32f/0x6f0
> [ 25.242472] worker_thread+0x89/0x770
> [ 25.242481] ? pci_mmcfg_check_reserved+0xc0/0xc0
> [ 25.242488] kthread+0x18c/0x1e0
> [ 25.242493] ? process_one_work+0x6f0/0x6f0
> [ 25.242499] ? kthread_create_on_node+0xc0/0xc0
> [ 25.242506] ret_from_fork+0x2c/0x40
> [ 25.242511] Object at ffff880462eea960, in cache kmalloc-8 size: 8
> [ 25.242513] Allocated:
> [ 25.242514] PID = 170
> [ 25.242522] save_stack_trace+0x1b/0x20
> [ 25.242529] save_stack+0x46/0xd0
> [ 25.242533] kasan_kmalloc+0xad/0xe0
> [ 25.242537] __kmalloc_node+0x12c/0x2b0
> [ 25.242542] alloc_cpumask_var_node+0x3c/0x60
> [ 25.242546] alloc_cpumask_var+0xe/0x10
> [ 25.242550] irq_affinity_notify+0x94/0x230
> [ 25.242555] process_one_work+0x32f/0x6f0
> [ 25.242559] worker_thread+0x89/0x770
> [ 25.242564] kthread+0x18c/0x1e0
> [ 25.242568] ret_from_fork+0x2c/0x40
> [ 25.242569] Freed:
> [ 25.242570] PID = 0
> [ 25.242572] (stack is not available)
> [ 25.242573] Memory state around the buggy address:
> [ 25.242578] ffff880462eea800: fc fc 00 fc fc 00 fc fc 00 fc fc 00
> fc fc fb fc
> [ 25.242582] ffff880462eea880: fc fb fc fc fb fc fc 00 fc fc 00 fc
> fc 00 fc fc
> [ 25.242586] >ffff880462eea900: 00 fc fc 00 fc fc 00 fc fc fb fc fc
> 00 fc fc fc
> [
> 25.242588]
> ^
> [ 25.242592] ffff880462eea980: fc fc fc fc fc fc fc fc fc fc fc fc
> fc fc fc fc
> [ 25.242596] ffff880462eeaa00: fc fc fc fc fc fc fc fc fc fc fc fc
> fc fc fc fc
> [ 25.242597]
> ==================================================================
>
> Fixes: 96db776a3682 ("i40e/i40evf: fix interrupt affinity bug")
> Signed-off-by: Stefano Brivio <sbri...@redhat.com>
> ---
> This should be considered for -stable, back to 4.10.
>
> drivers/net/ethernet/intel/i40e/i40e_main.c | 2 +-
> drivers/net/ethernet/intel/i40evf/i40evf_main.c | 2 +-
> 2 files changed, 2 insertions(+), 2 deletions(-)
This is already resolved with a previous patch from Jacob Keller, see
the following commit in my tree:
commit f15ac286b0d111499e0fec4b50c8c870ad3b4573
Author: Jacob Keller <jacob.e.kel...@intel.com>
Date: Wed Aug 16 17:12:00 2017 -0700
i40e: use cpumask_copy instead of direct assignment
According to the header file cpumask.h, we shouldn't be directly
copying
a cpumask_t, since its a bitmap and might not be copied correctly.
Lets
use the provided cpumask_copy() function instead.
Signed-off-by: Jacob Keller <jacob.e.kel...@intel.com>
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