Re: [PATCH] binfmt_misc: fix shift-out-of-bounds in check_special_flags
From: Kees Cook
Date: Fri Dec 02 2022 - 16:58:38 EST
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