| Message ID | 20221031055833.3966222-1-cuigaosheng1@huawei.com |
|---|---|
| State | Awaiting Upstream |
| Headers | show |
| Series | ext4: fix undefined behavior in bit shift for ext4_check_flag_values | expand |
On Mon, 31 Oct 2022 13:58:33 +0800, Gaosheng Cui wrote: > 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> > > [...] Applied, thanks! [1/1] ext4: fix undefined behavior in bit shift for ext4_check_flag_values commit: 0cd464d06ba0b9941dd285042909dc4d94adb373 Best regards,
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 8d5453852f98..e2d12e6c998d 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -558,7 +558,7 @@ 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)
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> --- fs/ext4/ext4.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)