ext4: fix undefined behavior in bit shift for ext4_check_flag_values
authorGaosheng Cui <cuigaosheng1@huawei.com>
Mon, 31 Oct 2022 05:58:33 +0000 (13:58 +0800)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Sat, 7 Jan 2023 10:11:58 +0000 (11:11 +0100)
commit7753d6657873a2523a9989e6c09090cd503bbcda
treeb0e42e3eba32b65b730cb76fa70a514444fad864
parent7908b8a541b1578cc61b4da7f19b604a931441da
ext4: fix undefined behavior in bit shift for ext4_check_flag_values

commit 3bf678a0f9c017c9ba7c581541dbc8453452a7ae upstream.

Shifting signed 32-bit value by 31 bits is undefined, so changing
significant bit to unsigned. The UBSAN warning calltrace like below:

UBSAN: shift-out-of-bounds in fs/ext4/ext4.h:591:2
left shift of 1 by 31 places cannot be represented in type 'int'
Call Trace:
 <TASK>
 dump_stack_lvl+0x7d/0xa5
 dump_stack+0x15/0x1b
 ubsan_epilogue+0xe/0x4e
 __ubsan_handle_shift_out_of_bounds+0x1e7/0x20c
 ext4_init_fs+0x5a/0x277
 do_one_initcall+0x76/0x430
 kernel_init_freeable+0x3b3/0x422
 kernel_init+0x24/0x1e0
 ret_from_fork+0x1f/0x30
 </TASK>

Fixes: 9a4c80194713 ("ext4: ensure Inode flags consistency are checked at build time")
Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Link: https://lore.kernel.org/r/20221031055833.3966222-1-cuigaosheng1@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
fs/ext4/ext4.h