On 9/22/21 11:03 AM, Bart Van Assche wrote:
On 9/22/21 10:54 AM, Jens Axboe wrote:
On 9/22/21 11:50 AM, Bart Van Assche wrote:
Skip queue mapping for shared tag sets. This patch fixes the following bug:
==================================================================
BUG: KASAN: null-ptr-deref in null_map_queues+0x131/0x1a0 [null_blk]
Read of size 8 at addr 0000000000000000 by task modprobe/4320
CPU: 9 PID: 4320 Comm: modprobe Tainted: G E 5.15.0-rc2-dbg+ #2
Call Trace:
show_stack+0x52/0x58
dump_stack_lvl+0x49/0x5e
kasan_report.cold+0x64/0xdb
__asan_load8+0x69/0x90
null_map_queues+0x131/0x1a0 [null_blk]
blk_mq_update_queue_map+0x122/0x1a0
blk_mq_alloc_tag_set+0x1e8/0x570
null_init_tag_set+0x197/0x220 [null_blk]
null_init+0x1dc/0x1000 [null_blk]
do_one_initcall+0xc7/0x440
do_init_module+0x10a/0x3d0
load_module+0x115c/0x1220
__do_sys_finit_module+0x124/0x1a0
__x64_sys_finit_module+0x42/0x50
do_syscall_64+0x35/0xb0
entry_SYSCALL_64_after_hwframe+0x44/0xae
Thanks Bart, do you mind if I fold this one in? I can add a Fixes-by tag
as well.
That sounds good to me. In case this patch would be retained: the word "Skip"
in the description should be changed into "Fix".
Unfortunately my patch is not good enough. I run into other crashes with this
patch applied since with this patch some hwctx pointers may be NULL:
BUG: KASAN: null-ptr-deref in blk_mq_free_rqs+0x1f4/0x380
Read of size 8 at addr 0000000000000090 by task modprobe/5085
CPU: 19 PID: 5085 Comm: modprobe Tainted: G E 5.15.0-rc1-dbg+ #7
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014
Call Trace:
show_stack+0x52/0x58
dump_stack_lvl+0x38/0x49
kasan_report.cold+0x64/0xdb
__asan_load8+0x69/0x90
blk_mq_free_rqs+0x1f4/0x380
blk_mq_sched_free_requests+0x98/0xc0
blk_cleanup_queue+0xe6/0x110
blk_cleanup_disk+0x1f/0x40
null_del_dev.part.0+0xdf/0x2b0 [null_blk]
null_exit+0x65/0xb4 [null_blk]
__do_sys_delete_module.constprop.0+0x1dd/0x2e0
__x64_sys_delete_module+0x1f/0x30
do_syscall_64+0x35/0xb0
entry_SYSCALL_64_after_hwframe+0x44/0xae
Bart.
