Re: [PATCH v3 1/1] pgo: Fix sleep in atomic section in prf_open() v3

[Kees Cook]

On Sat, 5 Jun 2021 21:31:29 +0300, Jarmo Tiitto wrote:
> In prf_open() the required buffer size can be so large that
> vzalloc() may sleep thus triggering bug:
> 
> ======
>  BUG: sleeping function called from invalid context at include/linux/sched/mm.h:201
>  in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 337, name: cat
>  CPU: 1 PID: 337 Comm: cat Not tainted 5.13.0-rc2-24-hack+ #154
>  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
>  Call Trace:
>   dump_stack+0xc7/0x134
>   ___might_sleep+0x177/0x190
>   __might_sleep+0x5a/0x90
>   kmem_cache_alloc_node_trace+0x6b/0x3a0
>   ? __get_vm_area_node+0xcd/0x1b0
>   ? dput+0x283/0x300
>   __get_vm_area_node+0xcd/0x1b0
>   __vmalloc_node_range+0x7b/0x420
>   ? prf_open+0x1da/0x580
>   ? prf_open+0x32/0x580
>   ? __llvm_profile_instrument_memop+0x36/0x50
>   vzalloc+0x54/0x60
>   ? prf_open+0x1da/0x580
>   prf_open+0x1da/0x580
>   full_proxy_open+0x211/0x370
>   ....
> ======
> 
> [...]

Applied to for-next/clang/features, thanks! I made some additional tweaks
on top of this, in a separate patch I just sent out.

[1/1] pgo: Fix sleep in atomic section in prf_open() v3
      https://git.kernel.org/kees/c/d13b0485a7bb

-- 
Kees Cook