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From:   Kees Cook <keescook@chromium.org>
To:     ebiederm@xmission.com, liushixin2@huawei.com,
        Al Viro <viro@zeniv.linux.org.uk>
Cc:     Kees Cook <keescook@chromium.org>, linux-fsdevel@vger.kernel.org,
        linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] binfmt_misc: fix shift-out-of-bounds in check_special_flags
Date:   Fri,  2 Dec 2022 13:58:29 -0800
Message-Id: <167001830861.1882545.11740816202645494659.b4-ty@chromium.org>
In-Reply-To: <20221102025123.1117184-1-liushixin2@huawei.com>
References: <20221102025123.1117184-1-liushixin2@huawei.com>
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On Wed, 2 Nov 2022 10:51:23 +0800, Liu Shixin wrote:
> UBSAN reported a shift-out-of-bounds warning:
> 
>  left shift of 1 by 31 places cannot be represented in type 'int'
>  Call Trace:
>   <TASK>
>   __dump_stack lib/dump_stack.c:88 [inline]
>   dump_stack_lvl+0x8d/0xcf lib/dump_stack.c:106
>   ubsan_epilogue+0xa/0x44 lib/ubsan.c:151
>   __ubsan_handle_shift_out_of_bounds+0x1e7/0x208 lib/ubsan.c:322
>   check_special_flags fs/binfmt_misc.c:241 [inline]
>   create_entry fs/binfmt_misc.c:456 [inline]
>   bm_register_write+0x9d3/0xa20 fs/binfmt_misc.c:654
>   vfs_write+0x11e/0x580 fs/read_write.c:582
>   ksys_write+0xcf/0x120 fs/read_write.c:637
>   do_syscall_x64 arch/x86/entry/common.c:50 [inline]
>   do_syscall_64+0x34/0x80 arch/x86/entry/common.c:80
>   entry_SYSCALL_64_after_hwframe+0x63/0xcd
>  RIP: 0033:0x4194e1
> 
> [...]

Applied to for-next/execve, thanks!

[1/1] binfmt_misc: fix shift-out-of-bounds in check_special_flags
      https://git.kernel.org/kees/c/6a46bf558803

-- 
Kees Cook