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| author | Gaosheng Cui <cuigaosheng1@huawei.com> | 2022-10-31 14:25:36 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-11-16 11:57:10 +0300 |
| commit | fcbd2b336834bd24e1d9454ad5737856470c10d7 (patch) | |
| tree | a9273a1c24ee0868b3fd6a7b5cee58ca0441d30e | |
| parent | 8aae24b0ed767542e71159ba0756a1faea70a6b2 (diff) | |
| download | linux-fcbd2b336834bd24e1d9454ad5737856470c10d7.tar.xz | |
capabilities: fix undefined behavior in bit shift for CAP_TO_MASK
[ Upstream commit 46653972e3ea64f79e7f8ae3aa41a4d3fdb70a13 ]
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 security/commoncap.c:1252:2
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
cap_task_prctl+0x561/0x6f0
security_task_prctl+0x5a/0xb0
__x64_sys_prctl+0x61/0x8f0
do_syscall_64+0x58/0x80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
</TASK>
Fixes: e338d263a76a ("Add 64-bit capability support to the kernel")
Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Acked-by: Andrew G. Morgan <morgan@kernel.org>
Reviewed-by: Serge Hallyn <serge@hallyn.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | include/uapi/linux/capability.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/include/uapi/linux/capability.h b/include/uapi/linux/capability.h index 2ddb4226cd23..43a44538ec8d 100644 --- a/include/uapi/linux/capability.h +++ b/include/uapi/linux/capability.h @@ -427,7 +427,7 @@ struct vfs_ns_cap_data { */ #define CAP_TO_INDEX(x) ((x) >> 5) /* 1 << 5 == bits in __u32 */ -#define CAP_TO_MASK(x) (1 << ((x) & 31)) /* mask for indexed __u32 */ +#define CAP_TO_MASK(x) (1U << ((x) & 31)) /* mask for indexed __u32 */ #endif /* _UAPI_LINUX_CAPABILITY_H */ |