From: Peilin Ye <yepeilin.cs@gmail.com> stable inclusion from stable-5.10.2 commit d3f4117b0275b2fb2de3a034fe1060a80104833f bugzilla: 46859 -------------------------------- commit 0032ce0f85a269a006e91277be5fdbc05fad8426 upstream. ptrace_get_syscall_info() is potentially copying uninitialized stack memory to userspace, since the compiler may leave a 3-byte hole near the beginning of `info`. Fix it by adding a padding field to `struct ptrace_syscall_info`. Fixes: 201766a20e30 ("ptrace: add PTRACE_GET_SYSCALL_INFO request") Suggested-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Peilin Ye <yepeilin.cs@gmail.com> Reviewed-by: Dmitry V. Levin <ldv@altlinux.org> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20200801152044.230416-1-yepeilin.cs@gmail.com Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- include/uapi/linux/ptrace.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/include/uapi/linux/ptrace.h b/include/uapi/linux/ptrace.h index a71b6e3b03eb..83ee45fa634b 100644 --- a/include/uapi/linux/ptrace.h +++ b/include/uapi/linux/ptrace.h @@ -81,7 +81,8 @@ struct seccomp_metadata { struct ptrace_syscall_info { __u8 op; /* PTRACE_SYSCALL_INFO_* */ - __u32 arch __attribute__((__aligned__(sizeof(__u32)))); + __u8 pad[3]; + __u32 arch; __u64 instruction_pointer; __u64 stack_pointer; union { -- 2.25.0