KASAN found a UAF due to dangling pointer. As the report below says,
rmi_f11_attention() accesses drvdata->attn_data.data, which was freed in
rmi_irq_fn.
[ 311.424062] BUG: KASAN: use-after-free in
rmi_f11_attention+0x526/0x5e0 [rmi_core]
[ 311.424067] Read of size 27 at addr ffff88041fd610db by task
irq/131-i2c_hid/1162
[ 311.424075] CPU: 0 PID: 1162 Comm: irq/131-i2c_hid Not tainted
4.15.0-rc8+ #2
[ 311.424076] Hardware name: Razer Blade Stealth/Razer, BIOS 6.05
01/26/2017
[ 311.424078] Call Trace:
[ 311.424086] dump_stack+0xae/0x12d
[ 311.424090] ? _atomic_dec_and_lock+0x103/0x103
[ 311.424094] ? show_regs_print_info+0xa/0xa
[ 311.424099] ? input_handle_event+0x10b/0x810
[ 311.424104] print_address_description+0x65/0x229
[ 311.424108] kasan_report.cold.5+0xa7/0x281
[ 311.424117] rmi_f11_attention+0x526/0x5e0 [rmi_core]
[ 311.424123] ? memcpy+0x1f/0x50
[ 311.424132] ? rmi_f11_attention+0x526/0x5e0 [rmi_core]
[ 311.424143] ? rmi_f11_probe+0x1e20/0x1e20 [rmi_core]
[ 311.424153] ? rmi_process_interrupt_requests+0x220/0x2a0 [rmi_core]
[ 311.424163] ? rmi_irq_fn+0x22c/0x270 [rmi_core]
[ 311.424173] ? rmi_process_interrupt_requests+0x2a0/0x2a0 [rmi_core]
[ 311.424177] ? free_irq+0xa0/0xa0
[ 311.424180] ? irq_finalize_oneshot.part.39+0xeb/0x180
[ 311.424190] ? rmi_process_interrupt_requests+0x2a0/0x2a0 [rmi_core]
[ 311.424193] ? irq_thread_fn+0x3d/0x80
[ 311.424197] ? irq_finalize_oneshot.part.39+0x180/0x180
[ 311.424200] ? irq_thread+0x21d/0x290
[ 311.424203] ? irq_thread_check_affinity+0x170/0x170
[ 311.424207] ? remove_wait_queue+0x150/0x150
[ 311.424212] ? kasan_unpoison_shadow+0x30/0x40
[ 311.424214] ? __init_waitqueue_head+0xa0/0xd0
[ 311.424218] ? task_non_contending.cold.55+0x18/0x18
[ 311.424221] ? irq_forced_thread_fn+0xa0/0xa0
[ 311.424226] ? irq_thread_check_affinity+0x170/0x170
[ 311.424230] ? kthread+0x19e/0x1c0
[ 311.424233] ? kthread_create_worker_on_cpu+0xc0/0xc0
[ 311.424237] ? ret_from_fork+0x32/0x40
[ 311.424244] Allocated by task 899:
[ 311.424249] kasan_kmalloc+0xbf/0xe0
[ 311.424252] __kmalloc_track_caller+0xd9/0x1f0
[ 311.424255] kmemdup+0x17/0x40
[ 311.424264] rmi_set_attn_data+0xa4/0x1b0 [rmi_core]
[ 311.424269] rmi_raw_event+0x10b/0x1f0 [hid_rmi]
[ 311.424278] hid_input_report+0x1a8/0x2c0 [hid]
[ 311.424283] i2c_hid_irq+0x146/0x1d0 [i2c_hid]
[ 311.424286] irq_thread_fn+0x3d/0x80
[ 311.424288] irq_thread+0x21d/0x290
[ 311.424291] kthread+0x19e/0x1c0
[ 311.424293] ret_from_fork+0x32/0x40
[ 311.424296] Freed by task 1162:
[ 311.424300] kasan_slab_free+0x71/0xc0
[ 311.424303] kfree+0x90/0x190
[ 311.424311] rmi_irq_fn+0x1b2/0x270 [rmi_core]
[ 311.424319] rmi_irq_fn+0x257/0x270 [rmi_core]
[ 311.424322] irq_thread_fn+0x3d/0x80
[ 311.424324] irq_thread+0x21d/0x290
[ 311.424327] kthread+0x19e/0x1c0
[ 311.424330] ret_from_fork+0x32/0x40
[ 311.424334] The buggy address belongs to the object at
ffff88041fd610c0
which belongs to the cache kmalloc-64 of size 64
[ 311.424340] The buggy address is located 27 bytes inside of
64-byte region [ffff88041fd610c0, ffff88041fd61100)
[ 311.424344] The buggy address belongs to the page:
[ 311.424348] page:ffffea00107f5840 count:1 mapcount:0 mapping:
(null) index:0x0
[ 311.424353] flags: 0x17ffffc0000100(slab)
[ 311.424358] raw: 0017ffffc0000100 0000000000000000 0000000000000000
00000001802a002a
[ 311.424363] raw: dead000000000100 dead000000000200 ffff8804228036c0
0000000000000000
[ 311.424366] page dumped because: kasan: bad access detected
[ 311.424369] Memory state around the buggy address:
[ 311.424373] ffff88041fd60f80: 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00
[ 311.424377] ffff88041fd61000: fb fb fb fb fb fb fb fb fc fc fc fc
fb fb fb fb
[ 311.424381] >ffff88041fd61080: fb fb fb fb fc fc fc fc fb fb fb fb
fb fb fb fb
[ 311.424384] ^
[ 311.424387] ffff88041fd61100: fc fc fc fc fb fb fb fb fb fb fb fb
fc fc fc fc
[ 311.424391] ffff88041fd61180: fb fb fb fb fb fb fb fb fc fc fc fc
fb fb fb fb
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Nick Desaulniers <nick.desaulniers@xxxxxxxxx>
---
drivers/input/rmi4/rmi_driver.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/input/rmi4/rmi_driver.c b/drivers/input/rmi4/rmi_driver.c
index 4f2bb59..141ea22 100644
--- a/drivers/input/rmi4/rmi_driver.c
+++ b/drivers/input/rmi4/rmi_driver.c
@@ -230,8 +230,10 @@ static irqreturn_t rmi_irq_fn(int irq, void *dev_id)
rmi_dbg(RMI_DEBUG_CORE, &rmi_dev->dev,
"Failed to process interrupt request: %d\n", ret);
- if (count)
+ if (count) {
kfree(attn_data.data);
+ attn_data.data = NULL;
+ }
if (!kfifo_is_empty(&drvdata->attn_fifo))
return rmi_irq_fn(irq, dev_id);
--
2.7.4