From: Gaosheng Cui <cuigaosheng1@xxxxxxxxxx>
[ 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@xxxxxxxxxx>
Acked-by: Andrew G. Morgan <morgan@xxxxxxxxxx>
Reviewed-by: Serge Hallyn <serge@xxxxxxxxxx>
Signed-off-by: Paul Moore <paul@xxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
include/uapi/linux/capability.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/uapi/linux/capability.h b/include/uapi/linux/capability.h
index 463d1ba2232a..3d61a0ae055d 100644
--- a/include/uapi/linux/capability.h
+++ b/include/uapi/linux/capability.h
@@ -426,7 +426,7 @@ 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 */
--
2.35.1
