Re: BUG: KASAN: use-after-free in blk_mq_sched_tags_teardown
From: John Garry
Date: Thu Oct 21 2021 - 08:18:00 EST
On 21/10/2021 13:01, Naresh Kamboju wrote:
Following KASAN BUG noticed on linux next 20211021 while booting qemu-arm64
with allmodconfig.
Thanks for the report.
I can't read comments and have broken the same thing twice ... please
try this change:
---8<---
diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c
index e85b7556b096..6a9444848e3a 100644
--- a/block/blk-mq-sched.c
+++ b/block/blk-mq-sched.c
@@ -541,7 +541,7 @@ static void blk_mq_sched_tags_teardown(struct
request_queue *q, unsigned int fla
queue_for_each_hw_ctx(q, hctx, i) {
if (hctx->sched_tags) {
- if (!blk_mq_is_shared_tags(q->tag_set->flags))
+ if (!blk_mq_is_shared_tags(flags))
blk_mq_free_rq_map(hctx->sched_tags);
hctx->sched_tags = NULL;
}
--- >8 ---
thanks
[ 77.613151][ T5] BUG: KASAN: use-after-free in
blk_mq_sched_tags_teardown+0x54/0x140
[ 77.616733][ T5] Read of size 4 at addr ffff000010d9b258 by task
kworker/0:0/5
[ 77.620107][ T5]
[ 77.621306][ T5] CPU: 0 PID: 5 Comm: kworker/0:0 Tainted: G
W T 5.15.0-rc6-next-20211021 #1
4d661763b10b5f85042868a82a033ba2fc3e45c4
[ 77.626986][ T5] Hardware name: linux,dummy-virt (DT)
[ 77.629480][ T5] Workqueue: events kobject_delayed_cleanup
[ 77.632269][ T5] Call trace:
[ 77.633853][ T5] dump_backtrace+0x0/0x340
[ 77.635938][ T5] show_stack+0x34/0x80
[ 77.637934][ T5] dump_stack_lvl+0x88/0xd8
[ 77.640070][ T5] print_address_description.constprop.0+0x38/0x340
[ 77.643034][ T5] __kasan_report+0x160/0x200
[ 77.645227][ T5] kasan_report+0x5c/0x180
[ 77.647312][ T5] __asan_load4+0xc8/0x100
[ 77.649391][ T5] blk_mq_sched_tags_teardown+0x54/0x140
[ 77.651984][ T5] blk_mq_exit_sched+0x128/0x180
[ 77.654299][ T5] __elevator_exit+0x44/0x80
[ 77.656415][ T5] blk_release_queue+0x138/0x200
[ 77.658710][ T5] kobject_cleanup+0x144/0x200
[ 77.660971][ T5] kobject_delayed_cleanup+0x1c/0x40
[ 77.663404][ T5] process_one_work+0x50c/0x880
[ 77.665684][ T5] worker_thread+0x3ec/0x740
[ 77.667838][ T5] kthread+0x220/0x240
[ 77.669740][ T5] ret_from_fork+0x10/0x20
[ 77.671778][ T5]
[ 77.672974][ T5] Allocated by task 1:
[ 77.674888][ T5] kasan_save_stack+0x30/0x80
[ 77.677082][ T5] __kasan_kmalloc+0x78/0x100
[ 77.679235][ T5] kmem_cache_alloc_trace+0x360/0x400
[ 77.681707][ T5] add_mtd_blktrans_dev+0x274/0x6c0
[ 77.684079][ T5] mtdblock_add_mtd+0x110/0x180
[ 77.686333][ T5] blktrans_notify_add+0x68/0xc0
[ 77.688521][ T5] add_mtd_device+0x4e8/0x6c0
[ 77.690659][ T5] mtd_device_parse_register+0x13c/0x3c0
[ 77.693258][ T5] physmap_flash_probe+0x83c/0x8c0
[ 77.695630][ T5] platform_probe+0x98/0x140
[ 77.697776][ T5] really_probe+0x234/0x6c0
[ 77.699913][ T5] __driver_probe_device+0x144/0x240
[ 77.702307][ T5] driver_probe_device+0x68/0x140
[ 77.704502][ T5] __driver_attach+0x1f0/0x280
[ 77.706598][ T5] bus_for_each_dev+0xdc/0x1c0
[ 77.708669][ T5] driver_attach+0x40/0x80
[ 77.710621][ T5] bus_add_driver+0x1c0/0x300
[ 77.712660][ T5] driver_register+0x170/0x200
[ 77.714749][ T5] __platform_driver_register+0x50/0x80
[ 77.717148][ T5] physmap_init+0x5c/0xfc
[ 77.719074][ T5] do_one_initcall+0xb0/0x2c0
[ 77.721127][ T5] do_initcalls+0x17c/0x244
[ 77.723109][ T5] kernel_init_freeable+0x2d4/0x378
[ 77.725376][ T5] kernel_init+0x34/0x180
[ 77.727304][ T5] ret_from_fork+0x10/0x20
[ 77.729261][ T5]
[ 77.730367][ T5] Freed by task 1:
[ 77.732009][ T5] kasan_save_stack+0x30/0x80
[ 77.734083][ T5] kasan_set_track+0x30/0x80
[ 77.736085][ T5] kasan_set_free_info+0x34/0x80
[ 77.738261][ T5] ____kasan_slab_free+0xfc/0x1c0
[ 77.740433][ T5] __kasan_slab_free+0x3c/0x80
[ 77.742518][ T5] slab_free_freelist_hook+0x1d4/0x2c0
[ 77.744892][ T5] kfree+0x160/0x300
[ 77.746618][ T5] blktrans_dev_release+0x64/0x100
[ 77.748821][ T5] del_mtd_blktrans_dev+0x1c0/0x240
[ 77.751079][ T5] mtdblock_remove_dev+0x28/0x80
[ 77.753246][ T5] blktrans_notify_remove+0xa4/0x140
[ 77.755507][ T5] del_mtd_device+0x84/0x1c0
[ 77.757541][ T5] mtd_device_unregister+0x90/0xc0
[ 77.759764][ T5] physmap_flash_remove+0x58/0x180
[ 77.762012][ T5] platform_remove+0x48/0xc0
[ 77.764032][ T5] __device_release_driver+0x1dc/0x340
[ 77.766393][ T5] driver_detach+0x138/0x200
[ 77.768396][ T5] bus_remove_driver+0x100/0x180
[ 77.770554][ T5] driver_unregister+0x64/0xc0
[ 77.772633][ T5] platform_driver_unregister+0x28/0x80
[ 77.775042][ T5] physmap_init+0xc4/0xfc
[ 77.776994][ T5] do_one_initcall+0xb0/0x2c0
[ 77.779028][ T5] do_initcalls+0x17c/0x244
[ 77.781023][ T5] kernel_init_freeable+0x2d4/0x378
[ 77.783269][ T5] kernel_init+0x34/0x180
[ 77.785196][ T5] ret_from_fork+0x10/0x20
[ 77.787135][ T5]
[ 77.788230][ T5] The buggy address belongs to the object at
ffff000010d9b200
[ 77.788230][ T5] which belongs to the cache kmalloc-512 of size 512
[ 77.793866][ T5] The buggy address is located 88 bytes inside of
[ 77.793866][ T5] 512-byte region [ffff000010d9b200, ffff000010d9b400)
[ 77.799169][ T5] The buggy address belongs to the page:
[ 77.801555][ T5] page:fffffc0000436600 refcount:1 mapcount:0
mapping:0000000000000000 index:0x0 pfn:0x50d98
[ 77.805683][ T5] head:fffffc0000436600 order:2
compound_mapcount:0 compound_pincount:0
[ 77.809109][ T5] flags:
0x1fffe0000010200(slab|head|node=0|zone=0|lastcpupid=0xffff)
[ 77.812496][ T5] raw: 01fffe0000010200 fffffc0000436408
fffffc0000436908 ffff000006c03080
[ 77.816037][ T5] raw: 0000000000000000 00000000000a000a
00000001ffffffff 0000000000000000
[ 77.819566][ T5] page dumped because: kasan: bad access detected
[ 77.822255][ T5]
[ 77.823357][ T5] Memory state around the buggy address:
[ 77.825747][ T5] ffff000010d9b100: fc fc fc fc fc fc fc fc fc
fc fc fc fc fc fc fc
[ 77.829081][ T5] ffff000010d9b180: fc fc fc fc fc fc fc fc fc
fc fc fc fc fc fc fc
[ 77.832393][ T5] >ffff000010d9b200: fa fb fb fb fb fb fb fb fb
fb fb fb fb fb fb fb
[ 77.835714][ T5] ^
[ 77.838602][ T5] ffff000010d9b280: fb fb fb fb fb fb fb fb fb
fb fb fb fb fb fb fb
[ 77.841936][ T5] ffff000010d9b300: fb fb fb fb fb fb fb fb fb
fb fb fb fb fb fb fb
full boot log link,
https://pastebin.com/xL5MYSD6
Reported-by: Linux Kernel Functional Testing <lkft@xxxxxxxxxx>
--
Linaro LKFT
https://lkft.linaro.org