When responding to an affinity hint we directly copied a cpumask value,
intsead of using cpumask_copy. According to cpumask.h this is not
correct because cpumask_t is only guaranteed to have enough space for
the number of CPUs in the system, and may not be as big as we expect.
Thus a direct copy results in an out-of-bound read and potentially
a crash if the pages are aligned just right. This will be easily
detected on a kernel with KASAN enabled:
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", 2016-09-14)
Signed-off-by: Jacob Keller <jacob.e.kel...@intel.com>
Cc: sta...@vger.kernel.org # 4.10+
---
This updates the commit message for the original fix, and indicates that
it fixes a potential crash, as well as tagged the commit for stable and
added a Fixes to indicate which commit this fixes.
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(-)
diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c
b/drivers/net/ethernet/intel/i40e/i40e_main.c
index 397f1bcaed3e..50a7260b32c2 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -3450,7 +3450,7 @@ static void i40e_irq_affinity_notify(struct
irq_affinity_notify *notify,
struct i40e_q_vector *q_vector =
container_of(notify, struct i40e_q_vector, affinity_notify);
- q_vector->affinity_mask = *mask;
+ cpumask_copy(&q_vector->affinity_mask, mask);
}
/**
diff --git a/drivers/net/ethernet/intel/i40evf/i40evf_main.c
b/drivers/net/ethernet/intel/i40evf/i40evf_main.c
index 1ffd55e06a49..87175a14740e 100644
--- a/drivers/net/ethernet/intel/i40evf/i40evf_main.c
+++ b/drivers/net/ethernet/intel/i40evf/i40evf_main.c
@@ -520,7 +520,7 @@ static void i40evf_irq_affinity_notify(struct
irq_affinity_notify *notify,
struct i40e_q_vector *q_vector =
container_of(notify, struct i40e_q_vector, affinity_notify);
- q_vector->affinity_mask = *mask;
+ cpumask_copy(&q_vector->affinity_mask, mask);
}
/**
--
2.14.1.323.g792488f9a5e1
