linux-user: Check for bad event numbers in epoll_wait
The kernel checks that the maxevents parameter to epoll_wait is non-negative and not larger than EP_MAX_EVENTS. Add this check to our implementation, so that: * we fail these cases EINVAL rather than EFAULT * we don't pass negative or overflowing values to the lock_user() size calculation Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
This commit is contained in:
		
							parent
							
								
									700fa58e4b
								
							
						
					
					
						commit
						2ba7fae3bd
					
				| 
						 | 
				
			
			@ -11501,6 +11501,11 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
 | 
			
		|||
        int maxevents = arg3;
 | 
			
		||||
        int timeout = arg4;
 | 
			
		||||
 | 
			
		||||
        if (maxevents <= 0 || maxevents > TARGET_EP_MAX_EVENTS) {
 | 
			
		||||
            ret = -TARGET_EINVAL;
 | 
			
		||||
            break;
 | 
			
		||||
        }
 | 
			
		||||
 | 
			
		||||
        target_ep = lock_user(VERIFY_WRITE, arg2,
 | 
			
		||||
                              maxevents * sizeof(struct target_epoll_event), 1);
 | 
			
		||||
        if (!target_ep) {
 | 
			
		||||
| 
						 | 
				
			
			
 | 
			
		|||
| 
						 | 
				
			
			@ -2585,6 +2585,9 @@ struct target_epoll_event {
 | 
			
		|||
    abi_uint events;
 | 
			
		||||
    target_epoll_data_t data;
 | 
			
		||||
} TARGET_EPOLL_PACKED;
 | 
			
		||||
 | 
			
		||||
#define TARGET_EP_MAX_EVENTS (INT_MAX / sizeof(struct target_epoll_event))
 | 
			
		||||
 | 
			
		||||
#endif
 | 
			
		||||
struct target_rlimit64 {
 | 
			
		||||
    uint64_t rlim_cur;
 | 
			
		||||
| 
						 | 
				
			
			
 | 
			
		|||
		Loading…
	
		Reference in New Issue