Hi guys,
JFYI, While doing some testing on v5.9-rc1, I stumbled across this:
[ 218.792457]
==================================================================
[ 218.799686] BUG: KASAN: use-after-free in bt_iter+0x80/0xf8
[ 218.805248] Read of size 8 at addr ffff002a084d8a00 by task fio/1554
[ 218.811589]
[ 218.813074] CPU: 37 PID: 1554 Comm: fio Not tainted
5.9.0-rc1-31278-g9689aa7be1cb-dirty #755
[ 218.821499] Hardware name: Huawei D06 /D06, BIOS Hisilicon D06 UEFI
RC0 - V1.16.01 03/15/2019
[ 218.830012] Call trace:
[ 218.832453] dump_backtrace+0x0/0x2d0
[ 218.836106] show_stack+0x18/0x28
[ 218.839412] dump_stack+0xf4/0x168
[ 218.842806] print_address_description.constprop.12+0x6c/0x4ec
[ 218.848628] kasan_report+0x130/0x200
[ 218.852279] __asan_load8+0x9c/0xd8
[ 218.855757] bt_iter+0x80/0xf8
[ 218.858801] blk_mq_queue_tag_busy_iter+0x2dc/0x528
[ 218.863670] blk_mq_in_flight+0x80/0xb8
[ 218.867496] part_stat_show+0xd8/0x238
[ 218.871237] dev_attr_show+0x44/0x90
[ 218.874804] sysfs_kf_seq_show+0x128/0x1c0
[ 218.878890] kernfs_seq_show+0xa0/0xb8
[ 218.882630] seq_read+0x1c0/0x7d0
[ 218.885935] kernfs_fop_read+0x70/0x330
[ 218.889762] vfs_read+0xe4/0x250
[ 218.892980] ksys_read+0xc8/0x178
[ 218.896285] __arm64_sys_read+0x44/0x58
[ 218.900112] el0_svc_common.constprop.2+0xc4/0x1e8
[ 218.904893] do_el0_svc+0x90/0xa0
[ 218.908198] el0_sync_handler+0x150/0x1b8
[ 218.912196] el0_sync+0x158/0x180
[ 218.915498]
[ 218.916979] Allocated by task 1553:
[ 218.920459] kasan_save_stack+0x28/0x58
[ 218.924284] __kasan_kmalloc.isra.6+0xcc/0xf0
[ 218.928630] kasan_slab_alloc+0x18/0x28
[ 218.932457] slab_post_alloc_hook+0x64/0x2b8
[ 218.936717] kmem_cache_alloc+0x160/0x260
[ 218.940719] getname_flags+0x68/0x240
[ 218.944371] user_path_at_empty+0x30/0x68
[ 218.948370] vfs_statx+0xf8/0x200
[ 218.951674] __do_sys_newfstatat+0x84/0xd8
[ 218.955760] __arm64_sys_newfstatat+0x54/0x68
[ 218.960107] el0_svc_common.constprop.2+0xc4/0x1e8
[ 218.964888] do_el0_svc+0x90/0xa0
[ 218.968192] el0_sync_handler+0x150/0x1b8
[ 218.972191] el0_sync+0x158/0x180
[ 218.975493]
[ 218.976974] Freed by task 1553:
[ 218.980104] kasan_save_stack+0x28/0x58
[ 218.983928] kasan_set_track+0x28/0x40
[ 218.987667] kasan_set_free_info+0x24/0x48
[ 218.991752] __kasan_slab_free+0x104/0x188
[ 218.995838] kasan_slab_free+0x14/0x20
[ 218.999577] slab_free_freelist_hook+0x8c/0x190
[ 219.004097] kmem_cache_free+0x98/0x3e0
[ 219.007923] putname+0x8c/0xa8
[ 219.010968] filename_lookup.part.70+0x130/0x1e8
[ 219.015575] user_path_at_empty+0x50/0x68
[ 219.019573] vfs_statx+0xf8/0x200
[ 219.022878] __do_sys_newfstatat+0x84/0xd8
[ 219.026963] __arm64_sys_newfstatat+0x54/0x68
[ 219.031310] el0_svc_common.constprop.2+0xc4/0x1e8
[ 219.036091] do_el0_svc+0x90/0xa0
[ 219.039396] el0_sync_handler+0x150/0x1b8
[ 219.043394] el0_sync+0x158/0x180
[ 219.046696]
[ 219.048178] The buggy address belongs to the object at ffff002a084d8000
[ 219.048178] which belongs to the cache names_cache of size 4096
[ 219.060771] The buggy address is located 2560 bytes inside of
[ 219.060771] 4096-byte region [ffff002a084d8000, ffff002a084d9000)
[ 219.072668] The buggy address belongs to the page:
[ 219.077456] page:0000000099a7b02f refcount:1 mapcount:0
mapping:0000000000000000 index:0x0 pfn:0x2a084d8
[ 219.086924] head:0000000099a7b02f order:3 compound_mapcount:0
compound_pincount:0
[ 219.094396] flags: 0x2ffff00000010200(slab|head)
[ 219.099006] raw: 2ffff00000010200 dead000000000100 dead000000000122
ffff002a53180f00
[ 219.106739] raw: 0000000000000000 0000000000070007 00000001ffffffff
0000000000000000
[ 219.114469] page dumped because: kasan: bad access detected
[ 219.120028]
[ 219.121507] Memory state around the buggy address:
[ 219.126287] ffff002a084d8900: fb fb fb fb fb fb fb fb fb fb fb fb fb
fb fb fb
[ 219.133499] ffff002a084d8980: fb fb fb fb fb fb fb fb fb fb fb fb fb
fb fb fb
[ 219.140709] >ffff002a084d8a00: fb fb fb fb fb fb fb fb fb fb fb fb fb
fb fb fb
[ 219.147918] ^
[ 219.151135] ffff002a084d8a80: fb fb fb fb fb fb fb fb fb fb fb fb fb
fb fb fb
[ 219.158347] ffff002a084d8b00: fb fb fb fb fb fb fb fb fb fb fb fb fb
fb fb fb
[ 219.165555]
==================================================================
Here's my steps to recreate (some may be redundant):
root@ubuntu:/sys/class/block/sda/queue# more scheduler
[mq-deadline] kyber bfq none
fio /home/john/sda.fio # just run fio on sda
echo 400 > nr_requests
fio /home/john/sda.fio
echo 30 > nr_requests
fio /home/john/sda.fio
echo none > scheduler
fio /home/john/sda.fio [issue triggered here]
I assume that this is a block issue, I'll have a look when I can.
Cheers,
john
Some config options (in addition to KASAN):
john@htsatcamb-server:~/kernel-dev4$ more .config | grep BLK
CONFIG_BLK_CGROUP=y
CONFIG_BLK_DEV_INITRD=y
CONFIG_CRYPTO_AES_ARM64_CE_BLK=y
CONFIG_CRYPTO_AES_ARM64_NEON_BLK=m
CONFIG_BLK_RQ_ALLOC_TIME=y
CONFIG_BLK_SCSI_REQUEST=y
CONFIG_BLK_CGROUP_RWSTAT=y
CONFIG_BLK_DEV_BSG=y
CONFIG_BLK_DEV_BSGLIB=y
CONFIG_BLK_DEV_INTEGRITY=y
CONFIG_BLK_DEV_INTEGRITY_T10=y
CONFIG_BLK_DEV_ZONED=y
CONFIG_BLK_DEV_THROTTLING=y
# CONFIG_BLK_DEV_THROTTLING_LOW is not set
CONFIG_BLK_CMDLINE_PARSER=y
CONFIG_BLK_WBT=y
CONFIG_BLK_CGROUP_IOLATENCY=y
CONFIG_BLK_CGROUP_IOCOST=y
CONFIG_BLK_WBT_MQ=y
CONFIG_BLK_DEBUG_FS=y
CONFIG_BLK_DEBUG_FS_ZONED=y
CONFIG_BLK_SED_OPAL=y
# CONFIG_BLK_INLINE_ENCRYPTION is not set
CONFIG_BLK_MQ_PCI=y
CONFIG_BLK_MQ_VIRTIO=y
CONFIG_BLK_PM=y
CONFIG_MTD_BLKDEVS=y
CONFIG_BLK_DEV=y
CONFIG_BLK_DEV_NULL_BLK=m
CONFIG_BLK_DEV_PCIESSD_MTIP32XX=y
CONFIG_BLK_DEV_UMEM=y
CONFIG_BLK_DEV_LOOP=y
CONFIG_BLK_DEV_LOOP_MIN_COUNT=8
CONFIG_BLK_DEV_CRYPTOLOOP=y
CONFIG_BLK_DEV_DRBD=y
CONFIG_BLK_DEV_NBD=y
# CONFIG_BLK_DEV_SKD is not set
# CONFIG_BLK_DEV_SX8 is not set
# CONFIG_BLK_DEV_RAM is not set
CONFIG_XEN_BLKDEV_FRONTEND=y
# CONFIG_XEN_BLKDEV_BACKEND is not set
CONFIG_VIRTIO_BLK=y
CONFIG_BLK_DEV_RBD=y
# CONFIG_BLK_DEV_RSXX is not set
# CONFIG_BLK_DEV_NVME is not set
CONFIG_BLK_DEV_SD=y
# CONFIG_BLK_DEV_SR is not set
# CONFIG_BLK_DEV_3W_XXXX_RAID is not set
CONFIG_BLK_DEV_MD=y
CONFIG_BLK_DEV_DM_BUILTIN=y
CONFIG_BLK_DEV_DM=y
# NOTE: USB_STORAGE depends on SCSI but BLK_DEV_SD may
# CONFIG_SQUASHFS_4K_DEVBLK_SIZE is not set
# CONFIG_PSTORE_BLK is not set
