Re: [PATCH] null_blk: Fix a NULL pointer dereference

[Bart Van Assche <bvanassche@xxxxxxx>]

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.

Hi Jens,

That sounds good to me. In case this patch would be retained: the word "Skip"
in the description should be changed into "Fix".

Thanks,

Bart.