Re: [PATCH v2] bpf: Fix integer overflow in prealloc_elems_and_freelist()

From: patchwork-bot+netdevbpf
Date: Thu Sep 30 2021 - 12:20:12 EST


Hello:

This patch was applied to bpf/bpf.git (refs/heads/master):

On Thu, 30 Sep 2021 22:55:45 +0900 you wrote:
> In prealloc_elems_and_freelist(), the multiplication to calculate the
> size passed to bpf_map_area_alloc() could lead to an integer overflow.
> As a result, out-of-bounds write could occur in pcpu_freelist_populate()
> as reported by KASAN:
>
> [...]
> [ 16.968613] BUG: KASAN: slab-out-of-bounds in pcpu_freelist_populate+0xd9/0x100
> [ 16.969408] Write of size 8 at addr ffff888104fc6ea0 by task crash/78
> [ 16.970038]
> [ 16.970195] CPU: 0 PID: 78 Comm: crash Not tainted 5.15.0-rc2+ #1
> [ 16.970878] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014
> [ 16.972026] Call Trace:
> [ 16.972306] dump_stack_lvl+0x34/0x44
> [ 16.972687] print_address_description.constprop.0+0x21/0x140
> [ 16.973297] ? pcpu_freelist_populate+0xd9/0x100
> [ 16.973777] ? pcpu_freelist_populate+0xd9/0x100
> [ 16.974257] kasan_report.cold+0x7f/0x11b
> [ 16.974681] ? pcpu_freelist_populate+0xd9/0x100
> [ 16.975190] pcpu_freelist_populate+0xd9/0x100
> [ 16.975669] stack_map_alloc+0x209/0x2a0
> [ 16.976106] __sys_bpf+0xd83/0x2ce0
> [...]
>
> [...]

Here is the summary with links:
- [v2] bpf: Fix integer overflow in prealloc_elems_and_freelist()
https://git.kernel.org/bpf/bpf/c/30e29a9a2bc6

You are awesome, thank you!
--
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html