From 205ac16628aca9093931fcbdb4bcd00d0eb94132 Mon Sep 17 00:00:00 2001 From: Gaosheng Cui Date: Mon, 31 Oct 2022 13:58:33 +0800 Subject: [PATCH] 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: 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 Fixes: 9a4c80194713 ("ext4: ensure Inode flags consistency are checked at build time") Signed-off-by: Gaosheng Cui Link: https://lore.kernel.org/r/20221031055833.3966222-1-cuigaosheng1@huawei.com Signed-off-by: Theodore Ts'o Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman --- fs/ext4/ext4.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 2d84030d7b7fc..ae4f13c8fc8d8 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -559,7 +559,7 @@ enum { * * It's not paranoia if the Murphy's Law really *is* out to get you. :-) */ -#define TEST_FLAG_VALUE(FLAG) (EXT4_##FLAG##_FL == (1 << EXT4_INODE_##FLAG)) +#define TEST_FLAG_VALUE(FLAG) (EXT4_##FLAG##_FL == (1U << EXT4_INODE_##FLAG)) #define CHECK_FLAG_VALUE(FLAG) BUILD_BUG_ON(!TEST_FLAG_VALUE(FLAG)) static inline void ext4_check_flag_values(void)